Euro S50 Double Vanos Procedure (E36)

The following information is provided for reference purposes only; therefore, you should use it at your own risk: Euro S50 Double Vanos. In addition, in no event shall Beisan Systems, LLC or its members be liable for incidental, consequential, or special loss or damages of any kind, however, caused..

Introduction

“Vanos” is BMW’s name for its variable valve timing units. Vanos units, for example, take on various shapes and designs depending on the car year and model (engine model).

The vanos discussed here is BMW part # 11-36-1-404-701. In fact , it’s a double vanos, which means that both the intake and exhaust valve timing can be varied. Furthermore , this vanos unit is part of the BMW 6-cylinder engine Euro S50B32. Notably , three car models incorporated this engine: the 3-series Euro E36 M3 (96-99), as well as the Euro Z3 M Coupe (98-00) and the Euro Z3 M Roadster (96-00).

The Vanos has been experiencing a failure, primarily due to the deterioration of the Vanos intake rod seal. Buna rubber (Buna-N, NBR, Nitrile), a common rubber material, makes the cup seal; however, it has limited temperature and chemical resistance. Unfortunately, it performs poorly in the Vanos/engine environment. The seal hardens, shrinks, and develops flat surfaces. As a result, this deterioration causes the seal to lose its functional characteristics, leading to Vanos failure. Experts have consulted BMW about other Vanos failures in the past; however, BMW decided not to address the issues, stating, “We will not pursue further development.” BMW does not offer the Vanos rod seal as a separate part.

Euro S50 Double Vanos

You can replace the Buna rod seal with a Viton rubber rod seal. In fact, Viton (FKM, Fluorocarbon) has similar functional characteristics to Buna, but it has much higher temperature and chemical resistance characteristics. Euro S50 Double Vanos, an even better solution is to replace the rod seal with a Teflon equivalent. Specifically, Teflon (PTFE filled) has a much lower friction property and is more appropriate for dynamic sealing than rubber. It’s compatible with the engine environment and is a standard material for this rod cup seal design. An O-ring provides energizing support for the Teflon when inserted into the cup. In fact, manufacturers best make the O-ring from Viton to handle the engine environment.

The Vanos intake piston seal can develop issues due to the Teflon ring and Viton rubber backing. Specifically, the seal can tilt and wear unevenly, caused by two main factors. First, a rod seal failure leads to leakage from an oil chamber on one side, while pressure from the opposite oil chamber forces the seal to tilt. Second, the piston seal cavity is too wide, due to the introduction of a paper gasket between piston parts. Although this gasket prevents rotation during assembly, it has no function afterward. To resolve the issue, you should replace the rod seal with one that doesn’t fail, which will eliminate oil leakage. Additionally, removing the paper gasket restores the correct piston seal cavity width, preventing unnecessary space and allowing the seal to function properly.

The vanos exhaust piston seals can also fail in their function. There are two piston seals, and each consists of a Teflon ring with a backing Viton O-ring. The failure is due to loose seal fit. This problem appears to result from a combination of Teflon material wear and O-ring compression set (flattening).

BMW M3 E36 Engine

The Teflon filler material is Bronze, which is appropriate for this vanos application. On the other hand , Viton comes in variations of materials, and some are less susceptible to compression set.

To address the piston seals problem, the solution involves slightly thickening the Teflon rings while also using Viton O-rings that are less prone to compression set. Importantly, the Beisan-sourced Viton O-rings have consistently demonstrated excellent compression set characteristics over time.

The Euro S50 Double Vanos also fail, and in some cases, this causes an external oil leak. In contrast, the older O-rings, which are made from Buna, tend to harden and flatten.
Replacing the O-rings with Viton O-rings has proven to be ineffective. Specifically, the Viton O-rings shred under the high oil pressure. As a result, BMW has redesigned the solenoid O-rings for the S62 engine (E39 M5) Vanos unit. Interestingly, the S62 Vanos solenoids are identical to the Euro S50 Vanos solenoids and, therefore, share the same O-rings.

On the other hand, the new S62 solenoid O-rings are not only made from Viton but also feature multiple facets, which significantly enhance their performance. These facets work to divert oil flow away from the O-ring, thereby preventing it from shredding. Similarly, these facets function to redirect the oil flow, effectively keeping the O-ring from shredding.
Furthermore, the new S62 vanos solenoid O-rings represent the correct design and can be used for this application. It’s worth noting that these O-rings are purchased directly from BMW and are not included in the Beisan seals kit.

Additionally, the Vanos system incorporates multiple O-rings for static sealing. With the exception of one, all the O-rings are made from Viton, which is the ideal material for this purpose.

. But over time, as a result, they experience compression set (flattening) and therefore need replacement.
The static sealing O-rings can be replaced with a set of Viton O-rings.

A Vanos seals/O-rings repair kit is available for purchase through Beisan Systems (bee-saan) on their website: www.beisansystems.com/products. This kit includes a replacement intake rod Teflon cup seal, which features an inserted Viton O-ring, as well as an intake piston seal composed of a Teflon ring and a machined Viton rubber ring. Additionally , the kit provides exhaust piston seals, which feature slightly thickened Teflon rings and backup Viton O-rings, as well as a replacement set of the static Viton O-rings.

Symptoms

Cars experience the following issues:
There is an overall loss of torque and power, especially in the lower RPM range, below 3k. Additionally , drivers may notice bogging and surging at 3k RPM, along with uneven power distribution and RPM transitions. Engine hesitations are also common in the lower RPM range, particularly below 3k. Moreover , a louder idle and intermittent idle RPM hiccups can occur, leading to difficult takeoffs. In some cases , turning on the AC results in a noticeable loss of power or bogging, and fuel consumption tends to increase.

Repairing the vanos seals provides significant improvements:
Firstly , there is an overall increase in torque and power, particularly in the lower RPM range, below 3k. Furthermore , the repair resolves bogging and surging at 3k RPM, resulting in smooth and even power distribution and RPM transitions. Engine hesitations in the lower RPM range, below 3k, are also eliminated. In addition , the idle becomes quieter and more stable, while takeoffs become smooth and effortless. Notably , performance improves even when the AC is on, and fuel consumption is reduced.

Diagnosis

Repair Procedure

The following is a Euro S50 Double Vanos R&R (remove and replace) procedure. In contrast, the valve cover gaskets and bolt grommets on the Euro S50 engine are made from Viton, and thus do not fail or need replacement.

Repair Time: 5 hours for a mechanic, 7+ hours for DIY.

Parts, Tools, and Shop Supplies:

Parts with the part number pattern xx-xx-x-xxx-xxx are genuine BMW parts and can be purchased directly from a BMW dealership. Additionally, Beisan Systems offers only the Vanos seals repair kit.

Euro S50 double vanos seals repair kit (BS041) $80/each (www.beisansystems.com)

You will need the following components:
4 x large solenoid O-ring (11-36-7-830-828) at $2.29 each, and 4 x small solenoid O-ring (11-36-7-830-829) at $3.38 each.

Note: The are sourced from the Euro S50 Double Vanos system. Importantly , these O-rings have been redesigned with multiple facets to withstand high oil pressure and prevent shredding. Additionally , they are made from Viton, a material specifically chosen for its ability to resist high engine temperatures as well as synthetic oil degradation.

Euro S50 Double Vanos
The following components are available at the specified prices:

Vanos oil filter (11-36-1-401-973): $16.27 each
Vanos oil filter washer (07-11-9-963-073): $0.09 each

Additionally:

Euro S50 Double Vanos intake solenoid cover gasket (11-36-1-402-659): $7.84 each
Vanos exhaust solenoid cover gasket (11-36-1-404-154): $7.84 each

Finally:Intake Splined Shaft and Piston Self-Locking Nut (11-36-1-313-170): $5.42 each.

Note: These parts are essential for maintaining the proper functioning of the Vanos system. As a result, they help ensure optimal performance and longevity.

Euro S50 Double Vanos
Tools and Equipment Required:

Hand Tools:
- 2 x putty knives (small, medium)
- Straight pick, hook pick, 90-degree pick
- Razor knife
- Medium-nose pliers (small)
Wrenches:
- 24mm combo wrench (not shown)
- 22mm combo wrench
- 12mm combo wrench
- 10mm combo wrench
- 7mm combo wrench
Screwdrivers and Accessories:
- Flathead screwdriver (medium head)
- Tack lifter
- Magnet pickup
- Mirror (medium)
Sockets and Bits:
- 24mm socket (1/2″)
- 10mm socket (3/8″)
- 4mm socket (6-point, 1/4″)
- 6mm hex bit socket (3/8″)
- 5mm hex bit socket (3/8″)
- 4mm hex bit socket (3/8″)
- 1/2″ to 3/8″ socket adapter
- 3/8″ to 1/4″ socket adapter
Ratchets:
- 1/2″ ratchet
- 3/8″ ratchet
- 1/4″ ratchet
- 1/2″ long-arm ratchet
- 3/8″ long-arm ratchet
Extensions:
- 3/8″ socket extension (short)
Torque Wrenches:
- Torque wrench (5 Nm [4 ft-lb], 12 Nm [9 ft-lb])

Note: These tools are essential for performing precise and efficient repairs, ensuring the job is done correctly.. Ensure all tools are in good condition before starting the task.

BMW Crankshaft Turning Socket (83-30-0-491-056): $68.04 each. However, it can be substituted with a 36mm 12-point socket (1/2″).

Mechanical Fan Removal Tools:

Wrenches and Holders:
- 32mm combo wrench
- BMW water pump pulley holder (part # 83-30-0-491-046): $37.76 each
Striking Tool:
- Handheld sledge hammer (3 lb)

Note: The BMW water pump pulley holder is available from aftermarket vendors and is often listed on platforms like eBay. Additionally, it is typically sold under its original BMW part number, 115030.

Tip: Using the correct tools not only ensures the safe and efficient removal of the mechanical fan but also prevents damage to surrounding components. Therefore, always verify that the tools are compatible with your specific vehicle model. It is often also available as part of a combination tool set, which includes a 32mm slim open wrench.

Materials and Tools Needed:

Cleaning Supplies:
- Paper towels
- Water-based cleaner (e.g., Simple Green, diluted 1:10)
- Brake cleaner
- Spray lubricant
- Assembly oil (or general-purpose lubricant oil)
Additional Supplies:
- Parts plate (to organize small components)
- Gasket sealant
- Magic marker (for labeling or marking parts)
- Small hose clamp (smallest standard size)

Repair Procedure Overview:

Preparation:

Ensure the car engine is completely cold before beginning the repair procedure. This is crucial for safety and to prevent damage to components.

Note that “Right” and “Left” designations are determined from the front of the car, as if standing at the hood facing the engine.

Removal Steps:

Fan and Shroud Removal:
Follow the specific steps for removing the fan and shroud, as these may vary depending on the vehicle model. For example, for the Euro E36 M3, refer to the dedicated procedure for fan and shroud removal.

Valve Cover Removal:
Next, proceed with the removal of the valve cover, ensuring that all bolts and fasteners are carefully organized on the parts plate to avoid any confusion during reassembly.

1. Remove the Engine Top Cover:

2. Disconnect the Ignition Coil Electrical Cable Connectors:
For each coil, pull up on the coil connector’s metal lock, then pull off the electrical cable connector.

3. Remove the Coil Electrical Cable Mounting Bracket:
Next, detach the 2 mounting nuts (10mm socket, 3/8″ ratchet & extension). Finally, remove the bracket from the mounting studs.

Step-by-Step Instructions:

Wedge the boot securely between the air conditioning valve stem and the upper cable harness boot

Remove the Rear Boot Rubber Block:

Begin by removing the coil cables’ rear boot rubber block from the valve cover. To do this, it can typically be done by gently prying it loose or unclipping it, depending on the design.

Reposition the Cables, Bracket, and Boot:

Once the rubber block is removed, carefully rotate the coil cables, bracket, and boot to the side.

Remove coils.
Remove 2 mounting nuts at each coil using a 10mm socket and 3/8″ ratchet, and extension. Then, pull up and out all coils.
Note: Maintain coil/cylinder association for reinstallation. This is not necessary but is good practice.

Detach the valve cover ground wire from the rear valve cover. Afterward, uncover the mounting nut using a 10mm socket, 3/8″ ratchet. Then, remove the ground wire from the valve cover stud and set it aside at the rear.

Step-by-Step Instructions for Removing the Valve Cover Mounting Bolts:

Prepare Your Tools:

Use a 10mm socket (3/8″) , a 3/8″ ratchet , and a socket extension to remove the 16 valve cover mounting bolts with grommets located around and the perimeter of the valve cover.

Additionally, have a tack lifter handy to assist in prying up any stubborn bolts or grommets if necessary.

Remove the Bolts:

Begin by systematically removing the 16 bolts from the perimeter of the valve cover. To ensure even tension release, work in a crisscross pattern as you remove the bolts.

Address the Rear Center Bolt (Limited Access):

The rear center bolt has limited access due to surrounding components. To remove it:

Use a 10mm socket (3/8″) , a 1/2″ ratchet , and a 1/2″ to 3/8″ socket adapter (with an extension if needed).

A tack lifter may also be helpful to gently lift the bolt once loosened.

Handle the Front Center Bolt:

Note that the front center bolt is shorter than the others. Take care when removing it to avoid losing it or confusing it with the other bolts during reassembly.

Remove 4 valve cover mounting bolts w/ grommets at center of valve cover (10mm socket 3/8″ / 3/8″ ratchet and extension, tack lifter).
Note: Bolts are short.

Remove valve cover from engine head.
Remove the valve cover from the engine head. Next, insert a blade (medium putty knife) between the valve cover gasket and the engine head, then pry up at all accessible locations on the front end to break the gasket bond. Be sure to break the gasket sealant bond at the front corners.
Repeat blade insertion and prying until the cover gasket seize breaks and the cover lifts. In some cases, notable prying might be needed at the front center to break the seize.
Note: If the valve cover cannot be removed, make sure to double-check that the 16 perimeter bolts and 4 center bolts have been removed.

Lift up and remove the valve cover from the engine head. Next, remove the valve cover perimeter gasket. Then, take out the valve cover sparkplug well gaskets.

Removal of vanos

Locate 4 center torx bolts on crankshaft pulley (mirror).

Mount crankshaft turning socket on crankshaft pulley 4 center torx bolts (mirror).

Mount ratchet on crankshaft turning socket (1/2″ long-arm ratchet).

f it’s a manual transmission, first, place the transmission in neutral. This allows for the turning of the crankshaft. Next, turn the crankshaft pulley clockwise until the cylinder 1 intake and exhaust cams point to each other at a ~45-degree angle (using a crankshaft turning socket and a 1/2″ long-arm ratchet).
Note: Turning crankshaft counter clockwise is acceptable.

Step-by-Step Instructions for Inspecting and Adjusting TDC (Top Dead Center) Timing Marks:

Reminder: If the timing marks on the harmonic balancer are not visible, they may be hidden behind the water pump pulley.Turn crankshaft pulley counter clockwise.
Note: Precise alignment is not necessary.

Inspect the TDC Timing Marks:

Locate the TDC timing marks on the engine timing cover and the crankshaft harmonic balancer. Afterward, verify their alignment to ensure accurate timing. These marks should align when the engine is at Top Dead Center.

Use a mirror to view the timing marks, which are typically positioned at approximately the 11 o’clock position on the harmonic balancer. In doing so, you can ensure a clear and accurate view of the marks.

Adjust the Crankshaft Pulley to Align TDC Marks:

If the timing marks are not aligned, use a crankshaft turning socket with a 1/2″ long-arm ratchet to gently rotate the crankshaft pulley.

Take off the Vanos electrical connectors cover. Next, uncover the 2 mounting nuts using a 10mm socket and 3/8″ ratchet. Then, lift off the cover.

Disconnect vanos intake and exhaust solenoid electrical cable connectors.
Press in connector wire clip and pull off connector.

Remove the Vanos intake and exhaust solenoid electrical cable connectors from the mounting brackets. Afterward, pull the connectors out from the brackets.

Insert a double-length, double-layer towel under the Vanos, and then rest it on the thermostat and radiator lower hose. This will provide additional support and protection during the process.

Remove the Vanos oil and accumulator pipe from the Vanos. Next, remove the oil pipe mounting bolt using a 12mm open wrench. Then, pull the oil pipe out from the Vanos and set it above the Vanos, as shown in the next picture.

Slightly loosen vanos oil pressure restrictor (22mm open wrench).
Note: Pressure restrictor work will be performed at bench. Loosening is easier to perform while vanos is mounted.

Take off vanos intake solenoid cover.
Detach 4 mounting bolts (4mm hex bit socket 3/8″ / 3/8″ ratchet).
Left cover. Eliminate cover paper gasket.

Mark positions of intake solenoids in vanos body.
Mark edge position of each solenoid circuit board on vanos body (marker).
Note: Marks are used to remount solenoids in their original rotational position.

Pry Upper Intake Solenoid Out of Vanos Body:
First, begin by positioning a medium-head flathead screwdriver against the vanos body. Then, carefully leverage the tool to pry the upper intake solenoid out of the mid-body groove.

If the solenoid does not come out easily, try prying from multiple positions. However, be patient and gentle, as excessive force could damage the surrounding components.

Important Notes:

It is crucial to avoid leveraging against the solenoid circuit board, as this can cause irreversible damage. Instead, always apply pressure against the vanos body or other sturdy surfaces.
Additionally, take extra care not to damage the solenoid wires during removal, as they are delicate and essential for proper functionality.

Once the solenoid is successfully removed, proceed with the next steps in the repair process. Press in wires before leveraging on groove adjacent to wires.

Pry Lower Intake Solenoid Out of Vanos Body:
First, position a medium-head flathead screwdriver against the vanos body. Then, gently leverage the tool to pry the lower intake solenoid out of the mid-body groove.

If the solenoid does not come out easily, try prying from multiple positions. However, exercise patience and caution, as excessive force could damage the surrounding components or the solenoid itself.

Important Notes:

It is critical to avoid leveraging against the solenoid circuit board, as this can lead to permanent damage. Instead, always apply pressure against the vanos body or other sturdy surfaces.
Additionally, take extra care not to damage the solenoid wires during removal, as they are delicate and essential for proper functionality.

Once the solenoid is successfully removed, you can proceed with the next steps in the repair process. First, press in the wires before leveraging on the groove adjacent to the wires.

Detach intake solenoids from vanos.

Lift Off Vanos Exhaust Solenoid Cover:
First, begin by eliminating the four mounting bolts that secure the vanos exhaust solenoid cover in place. To do this, use a 4mm hex bit socket with a 3/8″ ratchet.

Next, once all four bolts are removed, carefully take off the cover. Then, remove the cover’s paper gasket, ensuring it comes off cleanly without tearing or leaving residue behind.

Finally, set the cover and gasket aside in a safe place to avoid damage or contamination before proceeding with the next steps.

Mark Positions of Exhaust Solenoids in Vanos Body:
First, begin by marking the edge position of each solenoid circuit board on the vanos body using a marker. This step is crucial to ensure proper alignment during reinstallation.

Next, pay special attention to the lower solenoid, as its mark should be placed at the bottom left edge of the vanos body. For reference, see the picture below.

Additionally, it’s important to note that these marks are used to remount the solenoids in their original rotational position. This ensures optimal functionality and avoids potential issues during reassembly.

Finally, double-check the markings to confirm they are clear and accurate before proceeding to the next steps.

Pry Upper Exhaust Solenoid Out of Vanos Body:
First, position a medium-head flathead screwdriver against the vanos body. Then, carefully leverage the tool to pry the upper exhaust solenoid out of the mid-body groove.

Important Notes:

It is crucial to avoid leveraging against the solenoid circuit board, as this can cause irreversible damage. Instead, always apply pressure against the vanos body or other sturdy surfaces.
Additionally, take extra care not to damage the solenoid wires during removal, as they are delicate and essential for proper functionality.

Once the solenoid is successfully removed, you can proceed with the next steps in the repair process. Press in wires before leveraging on groove adjacent to wires.

Pry Lower Exhaust Solenoid Out of Vanos Body:
First, position a medium-head flathead screwdriver against the vanos body. Then, gently leverage the tool to pry the lower exhaust solenoid out of the mid-body groove.

If the solenoid does not come out easily, try prying from multiple positions. However, be patient and avoid using excessive force, as this could damage the surrounding components or the solenoid itself.

Important Notes:

It is essential to avoid leveraging against the solenoid circuit board, as this can lead to permanent damage. Instead, always apply pressure against the vanos body or other sturdy surfaces.
Additionally, take extra care not to damage the solenoid wires during removal, as they are delicate and critical for proper functionality.

Once the solenoid is successfully removed, you can proceed with the next steps in the repair process. First, press in the wires, and then leverage on the groove adjacent to the wires.

Remove exhaust solenoids from vanos.

Insert towels in vanos intake and exhaust solenoid chambers to protect oil passages from debris contamination (towels).

Fully Retard Exhaust Camshaft Timing:
First, place an open wrench (24mm combo wrench) on the hex at the front of the exhaust camshaft. Then, carefully rotate the exhaust camshaft counter-clockwise until it reaches the adjustment end position.

Once the camshaft is fully rotated, the groove on the first guide bearing will be roughly aligned with the groove on the first bearing cover. For reference, see the picture provided.

Important Note:

It is important to understand that adjusting the camshaft timing in this way causes full camshaft timing retard . As a result, this adjustment moves the splined shaft and vanos piston into a forward position. Consequently, this positioning facilitates easier access for disconnecting the splined shaft from the vanos piston in the upcoming step.

Finally, double-check the alignment and ensure the camshaft is securely in its retarded position before proceeding to the next step.

Fully Retard Intake Camshaft Timing:
First, place an open wrench (24mm combo wrench) on the hex at the front of the intake camshaft. Then, carefully rotate the intake camshaft counter-clockwise until it reaches the adjustment end position.

Once the camshaft is fully rotated, the groove on the first guide bearing will be roughly aligned with the groove on the first bearing cover. For reference, see the picture provided. If the camshaft is resistant to rotation, gently rock the camshaft back and forth to release the seize.
Note: In general, rotating the camshaft is most effective when standing on the exhaust side of the car.
Important Note:

Adjusting the camshaft timing in this way causes full camshaft timing retard . As a result, this adjustment moves the splined shaft and vanos piston into a forward position. Consequently, this positioning facilitates easier access for disconnecting the splined shaft from the vanos piston in the upcoming step.

Next, perform the rattle procedure to ensure the timing adjustment is properly completed and the system is ready for the next phase of work.

Finally, double-check the alignment and confirm that the camshaft is securely in its retarded position before proceeding further.

If performing the rattle repair, then continue at this point with the rattle procedure, specifically the Euro S50 Double Vanos Rattle Procedure.

Remove Vanos Intake Cylinder Cover Bolts:
First, begin by removing the six mounting bolts that secure the vanos intake cylinder cover in place. To do this, use a 4mm hex bit socket with a 3/8″ ratchet . Carefully loosen and remove each bolt one at a time.

Important Note:

If any of the bolts were not previously removed during earlier maintenance, you may notice a paint drop at the base of the bolt head or on the cover. This paint mark is used during car assembly to verify that the bolt was fully tightened with a torque wrench. Consequently, its presence indicates that the bolt has not been tampered with since the factory assembly.

Once all six bolts are removed, set them aside in a safe place to avoid loss or damage. Then, proceed to the next step in the repair process.

Detach Intake Cylinder Cover:
First, begin by prying the intake cylinder cover off using a small putty-knife. To remove the cover evenly, gently pry at multiple locations around the cover. This approach helps prevent damage to the cover or surrounding components.

Important Note:

When using the putty-knife, orient the blade with the edge ramp side facing the vanos body. This orientation is more effective for prying and reduces the risk of marring or damaging the surface.

Once the cover is detached, carefully set it aside in a safe place to avoid any damage before proceeding to the next step.
Note: Cover resistance is due to cover sealing O-ring.

Remove vanos intake piston mounting nut.
Initially loosen nut by counter holding splined shaft stud and unscrewing nut (7mm box wrench, 4mm socket (6-point) 1/4″ / 1/4″ ratchet).
Once nut is loosened, unscrew nut by counter holding nut and screwing splined shaft stud (7mm box wrench, 4mm socket (6 point) 1/4″ / 1/4″ ratchet).
When nut is close to end of shaft and shaft can no longer be held with tool, counter hold piston/shaft by hand and unscrew nut (fingers, 7mm box wrench).
: It is critical 6-point socket be used, as 12-point socket is susceptible to stripping shaft hex.
Note: Be sure to use wrench box end, as open wrench is susceptible stripping nut hex.

Remove Vanos 9 Mounting Bolts:
First, begin by removing the nine mounting bolts that secure the vanos unit in place. Use a 5mm hex bit socket with a 3/8″ ratchet to carefully loosen and remove each bolt.

Next, take note of the bolt arrangement: there are five upper bolts and four lower bolts . Among the upper bolts, pay special attention to the upper right and left end bolts , as they are longer than the others. Specifically, the right bolt is fully threaded , while the left bolt is partially threaded . This distinction is important for reassembly, so keep track of their positions as you remove them.

Once all nine bolts are removed, set them aside in a safe and organized manner to avoid confusion or loss during reinstallation.

Finally, proceed to the next step in the repair process.
Note: Lower second bolt from right also mounts vanos ground wire.

Remove Vanos Bridge Bolts:
First, begin by removing the four mounting bolts that secure the vanos bridge in place. Use a 6mm hex bit socket with a 3/8″ long-arm ratchet to carefully loosen and remove each bolt.

Next, take note of the bolt arrangement: the center two bolts are long , while the outer two bolts are short . This distinction is important for reassembly, so it’s crucial to keep track of their positions as you remove them. Organizing them in a way that reflects their original placement can help prevent confusion later on.

Once all four bolts are removed, set them aside in a safe and organized manner to avoid mixing them up during reinstallation.

Finally, proceed to the next step in the repair process.

Remove vanos bridge.
Wiggle vanos bridge while pulling up to remove vanos bridge from engine head.
Note: Gasket sealant at base of bridge acts as adhesive mounting bridge to engine head. Wiggling bridge helps break sealant bond.

Probevanos forward off engine head.
Pry between vanos and engine head at vanos top right and left ends (medium putty-knife).
Pry vanos evenly rotating between each side until vanos releases and separates from engine head.
Note: Vanos resistance is due to vanos intake and exhaust head sealing O-rings.

Pull Vanos Forward as Far as Possible:
First, carefully pull the vanos unit forward as far as it will go. Once the vanos comes off the engine head, it will be suspended on the intake and exhaust splined shafts . Be cautious during this step, as the vanos is still connected to critical components.

Important Note:

At this stage, it’s crucial to understand that the vanos should not be remounted onto the engine head without first aligning the exhaust side vanos oil pump with the camshaft oil pump driver . Misalignment can have serious consequences. Specifically, if the vanos is mounted under pressure from the mounting bolts while misaligned, it could result in the breakage of the vanos bridge , which is both costly and time-consuming to repair.

Once the vanos is safely pulled forward and you’ve ensured proper alignment considerations, proceed with the next steps in the repair process.

Reposition exhaust camshaft if necessary.
Exhaust sprocket hub can be in a position with an oil pump driver tower up.
If this occurs and precludes access to splined shaft stud and vanos exhaust piston for disconnection, turn crankshaft clockwise to position exhaust hub for better work access (picture) (crankshaft turning socket / 1/2″ long-arm ratchet).

Disconnect vanos exhaust piston from exhaust splined shaft stud.
Rotate vanos exhaust piston to allow tool access to splined shaft stud flats (10mm open wrench).

Disconnect vanos exhaust piston from exhaust splined shaft stud.
Counter hold splined shaft stud and unscrew vanos exhaust piston; left hand thread (7mm open wrench, 10mm open wrench).
Note: Piston and shaft stud are left hand thread, thus unscrew by turning piston tool (10mm open wrench) from left to right (clockwise) (car front orientation).
Note: Rotate piston tool (10mm open wrench) at every turn to facilitate tool access.

Remove Vanos from Engine Head:
First, begin by lifting the vanos unit upward while gently wiggling and pulling it forward. This motion will help detach the vanos intake piston from the intake splined shaft stud .

Important Note:

Keep in mind that the splined shaft stud inserted into the piston has an O-ring at its center , which mates with the inner diameter of the piston. This O-ring creates a tight seal, so you may need to apply steady pressure to overcome the resistance as you remove the piston from the stud.

Once you fully detach the Vanos intake piston from the splined shaft stud, carefully set the Vanos unit aside in a safe location to avoid damaging it.

Finally, proceed with the next steps in the repair process. Resistance to removal is due to this O-ring.

Take vanos to work bench.
Clean outside of vanos to remove dirt and sludge (brake cleaner & towels).

Installation of vanos seals

During following seals installation procedure, great care should be taken to not drop and damage vanos components. Perform work over table, so if part is dropped it will fall to table top.

Note: Try to not disturb vanos oil pump rotational position. Oil pump is currently aligned to mate with exhaust camshaft oil pump driver.

Installation of vanos intake seals

Remove intake piston from intake cylinder.
Press piston from vanos inboard side to remove piston from vanos outboard side (finger).

Take off intake cylinder cover from vanos inboard side.
Lift off 5 mounting bolts (4mm hex bit socket 3/8″ / 3/8″ ratchet).

Step 1: Remove the intake cylinder cover.
Step 2: Pry the cover at multiple locations using a small putty knife to evenly remove it.
Note: Orient the blade with the edge ramp side facing the Vanos body. This orientation works more effectively.
Note: Cover resistance is due to cover sealing O-ring.

Remove intake cover washer (fingers).

Step 1: Remove the intake cylinder from the Vanos housing.
Step 2: Press the intake cylinder from the Vanos inboard side to push it out from the Vanos outboard side using a 24mm 1/2″ socket.

If cylinder resistant, hit press tool to knock out cylinder (1/2″ ratchet head side).

Remove Intake Cylinder Sealing O-ring:
First, begin by prying the sealing O-ring out of the cylinder groove using a hook pick . Carefully work the pick under the O-ring and lift it out of the groove to remove it from the cylinder.

Next, clean the intake cylinder thoroughly using brake cleaner and towels . This step is crucial to remove any dirt, debris, or old sealant that could interfere with the installation of a new O-ring.

Afterward, clean the intake cylinder vanos housing using the same method—apply brake cleaner and wipe it down with towels. Ensuring both the cylinder and the housing are clean will help guarantee a proper seal when reassembling the components.

Finally, once the cleaning process is complete, inspect the surfaces to ensure they are free of contaminants before proceeding to the next step.

Install new O-ring on intake cylinder.
Insert new O-ring in cylinder groove on one end and stretch other end over cylinder and drop into groove (fingers).
Lightly lubricate O-ring to ease cylinder installation (assembly oil).

Note: Intake cylinder O-ring is one of three identical O-rings. Other identical O-rings are intake inboard cover O-ring and exhaust outboard cover O-ring.

Lightly lubricate intake cylinder vanos housing to ease cylinder installation (assembly oil).
Insert intake cylinder into vanos housing from vanos outboard side.
Rotate cylinder in vanos to align cylinder cutouts with vanos housing oil access holes at sides of vanos cylinder housing.
Turn vanos inboard side down to keep cylinder in housing.

Remove intake cylinder outboard cover sealing O-ring.
Pry O-ring from cover groove and remove from cover (hook pick).

Clean intake cylinder cover (brake cleaner & towels).

Note: Do not install new cover O-ring at this time. Cover will be easier to install and remove in next step without cover O-ring.

Install and then remove intake cylinder outboard cover.
Align cover bolt holes to vanos body bolts holes.
Install cover 6 mounting bolts (4mm hex bit socket 3/8″).
Tighten bolts evenly in multiple passes.
Note: Tightening cover bolts presses intake cylinder into vanos housing.
Remove cover 6 mounting bolts (4mm hex bit socket 3/8″).
Remove cylinder cover.

Install new O-ring on intake cylinder cover.
Insert new O-ring in cover groove on one end and stretch other end over cover and drop into groove (fingers).
Lightly lubricate O-ring to ease cover installation (assembly oil).

Note: Intake cylinder cover O-ring is larger than two other similar in size O-rings.

Remove intake rod seal from intake inboard cylinder cover.
Pry rod seal from cover outboard side to remove it from cover inboard side (strait pick).

Remove intake cylinder inboard cover sealing O-ring.
Pry O-ring from cover groove and remove from cover (hook pick).

Clean intake cylinder inboard cover (brake cleaner & towels).

Install new O-ring on intake cylinder inboard cover.
Insert O-ring in cover groove on one end and stretch other end over cover and drop into groove (fingers).
Lightly lubricate O-ring to ease cover installation (assembly oil).

Note: Intake cylinder inboard cover O-ring is one of two remaining identical O-rings. Other identical O-ring is exhaust outboard cover O-ring.

Install new intake rod seal into intake cylinder inboard cover.
Insert seal into housing on one side and press seal into housing on opposite side.
Once seal inserts into housing, press seal fully into housing along its perimeter (thumb).
Seal should fully insert into housing (picture).
Press O-ring into rod seal to verify O-ring full insertion.

Disconnect intake piston end cap from main piston body (hands).

Remove intake piston seal from intake piston cap.
Pry piston seal from piston cap (small putty-knife).
Note: Orient putty-knife with edge ramp side to piston cap wall. This orientation is more effective.

Remove paper gasket from intake piston or piston cap.
Pry off and scrape off paper gasket as necessary from piston or piston cap (strait pick).
Fully remove all paper gasket.

Note: Paper gasket excessively widens piston seal groove allowing seal to tilt in groove and wear unevenly. Gasket only seems to function to better seat piston cap before mounting. This is not needed.

Install new piston seal rubber ring on piston cap shaft (fingers).
Fully insert rubber ring onto piston cap (fingers).

Stretch intake piston new Teflon ring.
Place Teflon ring on piston shaft and pick tool on Teflon ring (90 degree pick) (picture).
Leverage pick tool against piston and tilt pick tool to stretch out Teflon ring (90 degree pick).
Perform Teflon ring stretching at multiple locations along Teflon ring until Teflon ring notably stretches.
Note: Teflon ring needs to stretch sufficiently to install over piston seal rubber ring in next step.
Note: Multiple attempts can be made of stretching Teflon ring and attempting next step install.

Install piston seal Teflon ring onto piston seal rubber ring.
If Teflon ring is too small, repeat previous Teflon ring stretching step.
Continue stretching and attempting to install Teflon ring until it installs.
Do not over stretch Teflon ring. Stretch only sufficiently to install.
Fully insert Teflon ring onto rubber ring.

Mount intake piston cap onto intake piston.

Insert intake piston seal end into intake cylinder outboard side.
Lightly lubricate cylinder entry inner wall and piston Teflon ring (assembly oil).
Wiggle piston and press strait into cylinder.
Verify Teflon ring is inserting into cylinder at all perimeter locations. Reposition piston and reattempt insertion to facilitate Teflon ring full perimeter insertion.
Once all Teflon ring perimeter inserts into cylinder, wiggle piston and press strait into cylinder to fully insert Teflon ring into cylinder.
Note: Cylinder entry has chamfer which allows for stretched Teflon ring to be collected and inserted into cylinder.

Maintain piston in cylinder for 1 minute then remove.
This period allows Teflon ring to be compressed (resized) close to original size.
Remove piston from cylinder.
Note Teflon ring has decreased in diameter.

Remove piston cap from piston.
Place piston cap, shaft first, into intake cylinder outboard end.

Insert piston cap into cylinder by pressing with piston cap end.
Press cap ~1/3 down cylinder.

Place intake piston vertically with cap end down.

Slide intake cylinder cover washer onto piston.

Insert intake cylinder cover with new rod seal onto piston.
Lightly lubricate piston and rod seal inner Teflon lip (assembly oil).
Press cover strait onto piston without tilting.
Press cover over piston until ~10mm of piston is protruding from cover (next picture).

Clean vanos intake cylinder inboard side cover mating surfaces and cover mounting bolts (brake cleaner & towels).

Insert intake piston, cap end first, into intake cylinder inboard side.
Slide cylinder cover washer up to cover.
Insert piston into cylinder.
Mount piston to piston cap by pressing on piston and piston cap from both ends of cylinder (finger, hand).

Mount intake cylinder cover washer onto cylinder.
Fully seat washer.

Mount intake cylinder cover onto vanos body.
Rotate cover/piston to align cover holes with vanos body holes (picture).
Brace piston from vanos outboard side (finger) and press cover down piston and onto vanos body.
Rotate cover/piston to align cover holes with vanos body holes (picture).
Press cover onto vanos body.
If present, cover alignment small pin hole will insert onto vanos body alignment pin.

Install intake cover 5 mounting bolts (4mm hex bit socket 3/8″ / 3/8″ ratchet).
Tighten bolts evenly to draw cover evenly to vanos body.
Note: If top end of cover not inserting hit with object to insert (ratchet handle)
Fully tighten, 6 Nm (4.5 ft-lb) (4mm hex bit socket 3/8″ / 3/8″ torque wrench).
Note: Tighten bolts evenly in multiple passes. Verify one pass with all bolts fully tightened.

Installation of vanos exhaust seals

Eliminate vanos exhaust cylinder cover from vanos outboard side.
Take off cover 3 mounting bolts (5mm hex bit socket 3/8″ / 3/8″ ratchet).

Remove exhaust cylinder cover.
Pry cover at multiple locations to evenly remove cover (small putty-knife).
Note: Orient blade with edge ramp side to vanos body. This orientation is more effective.
Note: Cover resistance is due to cover sealing O-ring.

Remove exhaust piston from exhaust cylinder.
Press piston from vanos inboard side to remove piston from vanos outboard side (finger).

Remove exhaust cylinder cover sealing O-ring.
Pry O-ring from cover groove and remove from cover (hook pick).

Clean exhaust cylinder cover (brake cleaner & towels).

Install new O-ring on exhaust cylinder cover.
Insert O-ring in cover groove on one end and stretch other end over cover and drop into groove (fingers).
Lightly lubricate O-ring to ease cover installation (assembly oil).

Cut cross section of exhaust piston middle seal Teflon ring (razor knife).
Note: Rocking of blade while pressing helps create cutting motion.
Rotate blade in seal after cutting to note any remaining uncut seal (razor knife).

Remove cut Teflon ring from piston grove.

Cut cross section of exhaust piston middle seal O-ring (razor knife).
Note: Rocking of blade while pressing helps create cutting motion.
Rotate blade in seal after cutting to note any remaining uncut seal (razor knife).

Remove cut O-ring from piston grove.

Cut cross section of exhaust piston end seal Teflon ring (razor knife).
Note: Rocking of blade while pressing helps create cutting motion.
Rotate blade in seal after cutting to note any remaining uncut seal (razor knife).

Remove cut Teflon ring from piston grove.

Cut cross section of exhaust piston end seal O-ring (razor knife).
Note: Rocking of blade while pressing helps create cutting motion.
Rotate blade in seal after cutting to note any remaining uncut seal (razor knife).

Remove cut O-ring from piston grove.

When seals removal is complete, piston seal grooves will have exposed metal with no seals.

Clean exhaust piston (brake cleaner & towels).

Mount exhaust piston middle seal O-ring onto exhaust piston small end and roll O-ring along piston and drop into seal groove (fingers).
Center O-ring in seal groove (strait pick).

Mount exhaust piston middle seal Teflon ring onto exhaust piston small end.
Insert pick tool between Teflon ring and piston (90 degree pick) (picture).
Leverage pick tool against piston and tilt pick tool to stretch out Teflon ring (90 degree pick).
Perform Teflon ring stretching at multiple locations along Teflon ring until Teflon ring notably stretches.
Note: Teflon ring needs to stretch sufficiently to slide over piston larger diameter.

Place exhaust piston vertically with large end down.
Press down on Teflon ring from top end to press Teflon ring onto piston larger diameter (fingers/nails).
Move Teflon ring evenly along piston (picture).
Note: If Teflon ring difficult to press down repeat previous Teflon ring stretching step.

Slide Teflon ring down exhaust piston to seal groove rim (fingers/nails) (picture).

Press down on Teflon ring from top end to press Teflon ring onto piston seal groove rim and drop Teflon ring into seal groove (fingers/nails).
Move Teflon ring evenly along piston (picture).
Note: It has been found that it is practical to first compress this small Teflon ring as next step and insert it into the exhaust cylinder for a few minutes, as shown a few steps below.
After that continue here with the ring on the piston bottom.

Insert exhaust piston end seal O-ring in piston seal groove at one end and stretch other end over piston and drop into seal groove (fingers).
Center O-ring in seal groove (strait pick).

Insert exhaust piston end seal Teflon ring in piston seal groove at one end and stretch other end over piston and drop into seal groove (fingers).
Stretch Teflon ring at multiple location along Teflon ring before final stretch over piston and into groove (fingers).

Insert exhaust piston large end into exhaust cylinder outboard side.
Lightly lubricate cylinder entry inner wall and piston Teflon ring (assembly oil).
Wiggle piston and press strait into cylinder.
Verify Teflon ring is inserting into cylinder at all perimeter locations. Reposition piston and reattempt insertion to facilitate Teflon ring full perimeter insertion.
Once all Teflon ring perimeter inserts into cylinder, wiggle piston and press strait into cylinder to fully insert Teflon ring into cylinder.
Note: Cylinder entry has chamfer which allows for stretched Teflon ring to be collected and inserted into cylinder.

Caution: Once Teflon ring fully inserts into cylinder do not further insert piston into cylinder. There is a groove at cylinder middle that will entrap piston seal and piston will then be very difficult to remove.

Place small hose clamp around exhaust piston middle seal Teflon ring (small hose clamp).
Tighten clamp until it seats on piston (Philips).
Note: Only lightly tighten clamp on piston.

Note: Mounting clamp on piston middle seal Teflon ring will compress Teflon ring to close to original size and allow piston insertion in next step.

Remove hose clamp from exhaust piston (Philips).
Note Teflon ring has compressed.
Note: Clamp will leave slight crease on Teflon surface. This crease will rectify once Teflon ring is heated in engine.

Lightly lubricate exhaust piston middle seal Teflon ring (assembly oil).
Insert exhaust piston small end into exhaust cylinder outboard side.

Place flat object on exhaust piston end (small putty-knife handle).
Press down on piston with moderate pressure until piston inserts into cylinder (picture).
Note: During this step Piston middle seal Teflon ring is being inserted into exhaust smaller cylinder. Cylinder entry has chamfer which will allow for stretched Teflon ring to be collected and inserted into cylinder.

Maintain piston in cylinder for 1 minute then remove.
This period allows Teflon ring to be compressed (resized) close to original size.
Remove piston from cylinder by pressing piston from inboard side.
Note Teflon ring has decreased in diameter.

Insert exhaust piston small end first into exhaust cylinder outboard side and press piston into cylinder.

Clean vanos exhaust cylinder outboard side cover mating surfaces and cover mounting bolts (brake cleaner & towels).

Install exhaust cylinder cover on vanos.
Orient cover so that BMW insignia can be read (picture) (this presumes vanos intake side on right).
Align cover bolt holes to vanos body bolts holes.
Press cover onto vanos body.

Install exhaust cover 3 mounting bolts (5mm hex bit socket 3/8″ / 3/8″ ratchet).
Tighten bolts evenly to draw cover evenly to vanos body.
Fully tighten, 10 Nm (7 ft-lb) (5mm hex bit socket 3/8″ / 3/8″ torque wrench).
Note: Tighten bolts evenly in multiple passes. Verify one pass with all bolts fully tightened.

Remove vanos inboard intake head sealing O-ring.
Pry O-ring from housing groove and remove from vanos (hook pick).

Clean O-ring housing groove (brake cleaner & towels).

Install new O-ring on vanos inboard intake head sealing housing.
Insert new O-ring in housing groove on one end and stretch other end over housing and drop into groove (fingers).
Lightly lubricate O-ring to ease vanos installation (assembly oil).

Remove vanos inboard exhaust head sealing O-ring.
Pry O-ring from housing groove and remove from vanos (hook pick).

Clean O-ring housing groove (brake cleaner & towels).

Install new O-ring on vanos inboard exhaust head sealing housing.
Insert new O-ring in housing groove on one end and stretch other end over housing and drop into groove (fingers).
Lightly lubricate O-ring to ease vanos installation (assembly oil).

Remove vanos inboard oil feed head sealing O-ring.
Pry O-ring from face groove and remove from vanos (hook pick).

Clean O-ring face groove (brake cleaner & towels).

Install new O-ring on vanos inboard oil feed head sealing face.
Insert new O-ring in face groove (fingers).

Note: Oil feed O-ring is similar in size to oil pressure restrictor small O-ring. Oil feed O-ring is slightly thicker in cross section than oil pressure restrictor small O-ring.

Unscrew oil pressure restrictor from vanos body (hand).
Drain and discard oil from vanos.

Clean restrictor and vanos restrictor area (brake cleaner & towels).

Cut cross section of small O-ring on pressure restrictor (razor knife).
Note: Rocking of blade while pressing helps create cutting motion.
Note: Take care to not cut or damage adjacent plastic washer. Plastic washer has cut cross section.

Remove cut O-ring from pressure restrictor.

Remove large O-ring from pressure restrictor (90 degree pick).

Clean pressure restrictor O-ring grooves (brake cleaner & towels).

Install new large O-ring on pressure restrictor. Roll O-ring onto pressure restrictor until O-ring drops into base groove.
Install small O-ring on pressure restrictor. Roll O-ring onto pressure restrictor until O-ring drops into groove.
Note: White washer should be positioned in groove on side of regulator large end (picture).
Lightly lubricate O-rings to ease pressure restrictor installation (assembly oil).

Screw pressure restrictor into vanos body (hand).
Note: Pressure restrictor will be tightened once vanos is mounted on engine.

Remove intake splined shaft stud O-ring.
Pry O-ring from stud groove and remove from stud (90 degree pick).

Clean splined shaft stud (brake cleaner & towels).

Note: If installing rattle kit, delay splined shaft O-ring installation until after rattle kit installation.
Install new O-ring on intake splined shaft stud.
Insert new O-ring on splined shaft stud and roll O-ring down stud and drop into groove (fingers).
Lightly lubricate O-ring to ease vanos installation (assembly oil).

For intake and exhaust solenoid pair, perform following O-rings removal and install.

Cut cross section of solenoid small and large O-rings (razor knife).
Note: Rocking of blade while pressing helps create cutting motion.
Note: Do not press into solenoid as this nicks sealing surface.
Rotate blade in O-ring after cutting to note any remaining uncut O-ring (razor knife).
Remove cut O-rings from solenoid.

Clean solenoid (brake cleaner & towels).

Install new small and large O-rings on solenoid (fingers).
O-rings should not be twisted in final position.

Repeat solenoid O-rings removal and install for second solenoid.
Lightly lubricate O-rings to ease solenoid installation (assembly oil).

Repeat O-rings removal and install for second solenoid pair.

Remove vanos oil filter and washer (5mm hex bit socket 3/8″ / 3/8″ ratchet).

Clean vanos outer face at oil filter hole (brake cleaner & towels).

Install vanos new oil filter and washer (5mm hex bit socket 3/8″ / 3/8″ ratchet).
Fully tighten, 12 Nm (9 ft-lb) (5mm hex bit socket 3/8″ / 3/8″ torque wrench).

Remove towels from vanos solenoid chambers.
Clean vanos solenoid chambers (brake cleaner & towels).
Clean vanos solenoid housing and cover matting surfaces (brake cleaner & towels).
Note: Do not erase solenoid alignments marks.

Insert new clean towels in vanos solenoid chambers to protect oil passages from debris contamination (towels).

Cleaning of parts

Note: When cleaning parts, spray cleaning compound on towel then wipe component with towel. Components can also be placed in small container and sprayed with cleaning compound then individually wiped with towel.

Clean all mounting bolts, nuts, washers (brake cleaner & towels).

Clean vanos matting surfaces; solenoid covers and bolts, intake cylinder housing and cover bolts, inboard face (brake cleaner & towels).
Note: Do not rotate vanos exhaust oil pump.

Neat vanos bridge polished surfaces; top gasket surface, arches, base bottom (remove old sealant) (brake cleaner & towels).

Tidy head matting surfaces; sparkplug well, top perimeter and front half-moons, front polished surfaces, exhaust splined shaft stud (brake cleaner & towels).

Pure vanos ground wire and valve cover ground wire (brake cleaner & towels).

Fresh coils mounting contact surfaces (at coils) (brake cleaner & towels).

Remove valve cover gaskets from valve cover.
Clean valve cover gaskets (brake & towels). Note: Euro S50 valve cover gaskets are made of Viton and thus can withstand brake cleaner. Brake cleaner will allow for removing oil from gaskets.
Clean valve cover mating surfaces; inner gasket, bolt access holes, all studs (brake cleaner & towels).

Installation of vanos

Slightly advance exhaust camshaft position.
Rotate exhaust camshaft slightly clockwise (24mm open wrench).
Align exhaust timing grooves so camshaft bearing groove is slightly left of bearing cover groove (car rear orientation) (picture). If camshaft resistant to rotation rock camshaft back and forth to release seize.
Note: Rotating camshaft is most effective when standing at exhaust side of car.
Note: This step insures vanos exhaust piston will not bottom out on vanos exhaust cylinder cover and obstruct matting of vanos to cylinder head.

Slightly advance intake camshaft position.

Euro S50 Double Vanos

Rotate intake camshaft slightly clockwise (24mm open wrench).
Align intake timing grooves so camshaft bearing groove is slightly left of bearing cover groove (car rear orientation) (picture). If camshaft resistant to rotation rock camshaft back and forth to release seize.
Note: Rotating camshaft is most effective when standing at exhaust side of car.
Note: This step insures vanos intake piston/splined shaft stud do not protrude too far and obstruct mounting of vanos intake cylinder cover.

Inspect TDC (top dead center) timing marks on engine timing cover and crankshaft harmonic balancer at ~11 o”clock position (mirror).
If needed, adjust crankshaft pulley to align TDC timing marks (crankshaft turning socket / 1/2″ long-arm ratchet).
Note: Precise alignment is not necessary.

If crankshaft adjusted, double check and readjust camshafts timing as above.

After above camshafts adjustment, intake and exhaust splined shafts will be slightly more recessed into corresponding sprockets (picture).

Move vanos ground wire forward and position end under vanos solenoid cable connector bracket.
Note: This allows installing vanos on engine head without ground wire being caught between vanos and engine head.

Verify vanos inboard side is clean and ready for installation.
As needed, wipe down vanos inboard surfaces (brake cleaner & towels).
Note: Do not rotate vanos exhaust oil pump.

Install vanos on engine head.
Insert vanos intake piston onto intake splined shaft stud.
Stop when resistance is met.

Insert your thumb into the Vanos intake cylinder and press on the piston. Next, lift up the Vanos and wiggle and press it onto the engine head. Note: The intake splined shaft stud O-ring may seize on the piston inner walls, preventing insertion. However, wiggling and pressing the Vanos will help release the O-ring seize and facilitate the Vanos advancement. When this happens, the splined shaft stud will come through the piston front center hole, as shown in the picture. Finally, stop advancing the Vanos once the splined shaft stud protrudes from the Vanos intake piston.

Rotate exhaust splined shaft stud to facilitate tool access to stud flats (fingers).
Mount splined shaft stud tool and rest on pump drive left tower (7mm open wrench).

Install pliers onto the Vanos exhaust piston using medium-nose pliers. Next, lift the Vanos exhaust side and align the exhaust piston with the splined shaft stud. Then, pull the Vanos exhaust piston onto the splined shaft stud using the medium-nose pliers, adjusting the Vanos height as needed. While pressing the exhaust piston onto the splined shaft, thread the exhaust piston onto the splined shaft stud; note that it is a left-hand thread (medium-nose pliers). As a reminder, the piston and shaft stud are left-hand thread, so screw them in by turning the piston tool (medium-nose pliers) from right to left (counterclockwise), as viewed from the front of the car.

Thread the exhaust piston onto the splined shaft stud using a 10mm open wrench; remember, it is a left-hand thread. As a result, screw it in by turning the piston tool (10mm open wrench) from right to left (counterclockwise), as viewed from the front of the car. Note: The piston and shaft stud are left-hand thread, so be sure to rotate the piston tool (10mm open wrench) from right to left. If needed, rotate the piston tool at each turn to facilitate tool access.

Lightly tighten the connection, using the 10mm open wrench, making sure to follow the left-hand thread direction. Note: Since it’s a left-hand thread, it’s not necessary to over-tighten the joint.

Alignment of Vanos Oil Pump:
Now, proceed with aligning the Vanos oil pump as needed.

If needed, rotate the Vanos exhaust oil pump to align the holes with the camshaft drive tabs. Note: The oil pump might need slight adjustment due to the previous slight advance of the camshaft.

Press the Vanos onto the engine head and verify that the camshaft driver tabs insert into the oil pump holes. Next, press in the Vanos intake piston using your thumb.

If necessary, withdraw the Vanos from the engine head and realign the Vanos oil pump for proper fitment.

Press the Vanos onto the engine head until the Vanos head seal O-rings reach the head and resistance is encountered. Next, press in the Vanos intake piston using your thumb.

Then, verify that the oil pump drive tabs insert into the Vanos oil pump holes. If necessary, withdraw the Vanos from the engine head and realign the Vanos oil pump for proper fitment.

Wiggle the Vanos side to side while pressing it onto the engine head. In addition, press in the Vanos intake piston using your thumb.

Note: The Vanos O-rings will insert into the head’s half-moon arches as you continue this process.

Press both the Vanos intake and exhaust sides until the Vanos fully mates with the engine head, as shown in the picture. As a result, the exhaust camshaft drive tabs will fully insert into the Vanos oil pump holes.

If the Vanos does not fully mate with the engine head, it indicates there is an obstruction. In this case, withdraw the Vanos from the engine head to assess the obstruction.

Next, confirm that the exhaust camshaft timing bearing groove aligns slightly to the left of the groove on the bearing cover (car rear orientation), as shown in the picture above.
Check vanos ground wire is pulled forward and end is resting on vanos solenoid cable connector bracket.
Verify the alignment of the Vanos oil pump holes with the exhaust camshaft drive tabs.

Caution: It is critical that the Vanos mounts flush with the engine head; otherwise, damage could occur.

Withdraw the Vanos from the engine head. Then, wiggle the Vanos side to side while pulling it off the engine head. Continue withdrawing the Vanos until it stops.
Caution: It is critical that the Vanos oil pump rotation position not be changed; otherwise, damage could occur.

Apply a thin layer of sealant to the Vanos bridge bottom base surfaces. Afterward, allow the sealant to solidify for approximately 2 minutes before mounting the bridge.

Install the Vanos bridge onto the engine head. Ensure the bridge is oriented with the large arch on the exhaust side, as shown in the picture. Next, insert the bridge bottom side dowel holes (small) onto the engine head dowels. Finally, fully seat the bridge onto the engine head.

Install the Vanos bridge with the 4 mounting bolts using a 6mm hex bit socket and 3/8″ ratchet. Note: The center 2 bolts are long, and the outer 2 bolts are short. Next, fully tighten the bolts to 10 Nm (7 ft-lb) using a 6mm hex bit socket and a 3/8″ torque wrench. Remember: Tighten the bolts evenly in multiple passes, ensuring to verify that all bolts are fully tightened after one pass.

Wipe any excess sealant from the Vanos bridge base perimeter using your finger. Note: The engine head half-moons and Vanos bridge arches combine to create cavities for the Vanos inboard intake and exhaust protrusions to insert into. As a result, the Vanos intake and exhaust protrusion O-rings effectively seal engine oil from leaking externally.

Note: When vanos advances, splined shaft stud will come through piston front center hole (picture).

Press vanos onto engine head until vanos O-rings reach head / bridge and resistance is encountered.
Note: Vanos O-rings will insert partially into head / bridge.

Initially thread vanos 9 mounting bolts, 5 upper and 4 lower.
Note: The upper right and left end bolts are long. Additionally, the right bolt is fully threaded, while the left bolt is partially threaded. Furthermore, the lower second bolt from the right is used to mount the Vanos ground wire.

Tighten the 9 Vanos mounting bolts using a 5mm hex bit socket and a 3/8″ ratchet. Ensure to tighten the bolts evenly in multiple passes to draw the Vanos slowly and evenly to the engine head and Vanos bridge. As a result, the Vanos O-rings will insert into the engine head and Vanos bridge. Finally, the Vanos will fully mate with the engine head.

Caution: This is a critical step. If vanos oil pump is not correctly aligned with exhaust camshaft drive damage can occur. Tighten bolts evenly and note any resistance to bolt tightening and vanos insertion. If bolts are tighter on exhaust side and vanos is not inserting, stop. Remove the Vanos from the engine head and then repeat the procedure for aligning the Vanos oil pump.

Fully tighten vanos 9 mounting bolts, 8 Nm (6 ft-lb) (5mm hex bit socket 3/8″ / 3/8″ torque wrench).
Note: Tighten bolts evenly in multiple passes. Verify one pass with all bolts fully tightened.

Press on vanos intake piston end cap at multiple locations to fully seat cap on piston.
Clean piston cap and splined shaft stud (brake cleaner & towels).

Initially install vanos intake piston / splined shaft new mounting nut.
Screw nut on splined shaft stud (fingers).
Counter hold piston/shaft by hand and screw nut (fingers, 7mm box wrench).
Note: Nut can only be slightly installed on shaft. This allows slight section of shaft stud to protrude from nut and allow counter holding shaft in next step.

Fully mount nut by counter holding shaft stud and screwing on nut (4mm socket (6 point) 1/4″ / 1/4″ ratchet, 7mm open wrench).
Note: At first, shaft tool (4mm socket) will only barely mount on splined shaft end.

Fully tighten nut, 9 Nm (6.5 ft-lb) (7mm box wrench, 4mm socket (6 point) 1/4″ w/ 3/8″ to 1/4″ socket adapter / 3/8″ torque wrench).
Memo: It is critical 6-point socket be used, as 12-point socket is susceptible to stripping shaft hex.
Remark: Be sure to use wrench box end, as open wrench is susceptible to stripping nut hex.

Record: Intake piston end is recessed slightly into intake cylinder. This is due to slight advance (clockwise) adjustment of intake camshaft. This assures piston / splined shaft stud do not interfere with cylinder cover installation.

Install vanos intake cylinder cover.
Orient cover with side slight indent to vanos oil filter cap (picture right).
Press cover onto vanos body.

Install vanos intake cover 6 mounting bolts (4mm hex bit socket 3/8″ / 3/8″ ratchet).
Tighten bolts evenly to draw cover evenly to vanos body.
Fully tighten, 5 Nm (4 ft-lb) (4mm hex bit socket 3/8″ / 3/8″ torque wrench).
Note: Tighten bolts evenly in multiple passes. Verify one pass with all bolts fully tightened.

Fully advance exhaust camshaft position.
Rotate exhaust camshaft clockwise to adjustment end position (24mm open wrench). If camshaft resistant to rotation rock camshaft back and forth to release seize.
Note: Rotating camshaft is most effective when standing at exhaust side of car.

Note: Advanced exhaust timing is advantageous to engine starting.

Verification of engine timing

If rattle kit was installed, perform verification of engine timing procedure in rattle procedure.
Euro S50 Double Vanos Rattle Procedure

Installation of solenoids

Note vanos intake solenoid cable marked “1”, and exhaust solenoid cable marked “2”.

Remove towel from vanos intake solenoid chambers.
Insert vanos intake solenoids (#1) into intake solenoid chambers.
Rotate solenoids to align circuit board edge with hosing alignment marks.
Insert cable grommet in housing groove (bottom).

Press solenoids to insert fully into chambers.
Rotate solenoids if necessary to align further.
Verify solenoid cable has recessed into solenoid housing.

Press on solenoids to verify full insertion.

Apply multiple thin dots of sealant along solenoid cover matting surface (sealant / finger).

Place intake solenoid cover gasket on solenoid cover matting surface.
Align gasket with housing surface and bolt holes.
Press gasket to bind with sealant and hold on housing surface.

Mount solenoid cover and 4 mounting bolts.
Some alignment of bolts with cover gasket might be necessary.

Initially tighten solenoid cover 4 bolts (4mm hex bit socket / hand).
Fully tighten, 8 Nm (6 ft-lb) (4mm hex bit socket 3/8″ / 3/8″ torque wrench).
Note: Tighten bolts evenly in multiple passes. Verify one pass with all bolts fully tightened.

Remove towel from vanos exhaust solenoid chambers.
Insert vanos exhaust solenoids (#2) into exhaust solenoid chambers.
Rotate solenoids to align circuit board edge with hosing alignment marks.
Insert cable grommet in housing groove (bottom).

Press solenoids to insert fully into chambers.
Rotate solenoids if necessary to align further.
Verify solenoid cable has recessed into solenoid housing.

Press in solenoids to verify full insertion.

Apply multiple thin dots of sealant along solenoid cover matting surface (sealant / finger).

Place intake solenoid cover gasket on cover matting surface.
Align gasket with housing surface and bolt holes.
Press gasket to bind with sealant and hold on housing surface.

Mount solenoid cover and 4 mounting bolts.
Some alignment of bolts with cover gasket might be necessary.

Insert solenoid electrical cable connectors into connector brackets under vanos.
Note: Connectors are keyed with brackets and will only insert in one orientation.

Connect vanos electrical cable connectors to vanos solenoid cable connectors in connector brackets.
Note: Orient intake connector metal clip down and exhaust connector metal clip out.
Press in connectors until wire clip snaps into place.

Install vanos electrical connectors cover.
Align and install cover on connector bracket studs.

Mount cover 2 nuts (10mm socket 3/8″ / 3/8″ ratchet).
Lightly tighten.

Fully tighten vanos oil pressure restrictor, ~14 Nm (by feel) (22mm open wrench).

Install Vanos Oil Accumulator Pipe:
First, take the vanos oil accumulator pipe and carefully pull the oil pipe to the side. Then, insert the pipe into the designated vanos oil pipe hole.

Next, secure the oil pipe in place by screwing on the mounting bolt. Use a 12mm open wrench to tighten the bolt. Afterward, fully tighten the bolt to 20 Nm (by feel) using the same wrench. Be careful not to overtighten, as this could damage the threads or the pipe.

Installation of Valve Cover:
Once the vanos oil accumulator pipe is securely installed, proceed with the installation of the valve cover. Ensure all components are properly aligned before moving on to the next steps.

Mount Valve Cover Perimeter Gasket and Spark Plug Well Gaskets on Engine Head:
First, begin by preparing the valve cover perimeter gasket and the spark plug well gaskets. Carefully position them on the engine head, ensuring proper alignment for a secure fit.

Next, orient the spark plug well gaskets so that the end bolt hole faces toward the front of the engine, as shown in the picture. Additionally, make sure the perimeter ridges of the gaskets are facing downward to ensure a proper seal.

Once everything is correctly aligned, double-check the placement of both the perimeter gasket and the spark plug well gaskets. This step is crucial to prevent oil leaks and ensure a tight seal during operation.

Finally, proceed with the next steps of the installation process, ensuring all components are securely in place before moving forward.

Insert valve cover gasket two alignment dowels into respective bridge holes.

Install valve cover on engine head.
Align valve cover with engine head and gaskets and lay valve cover on engine head.
Adjust valve cover perimeter gasket so each valve cover gasket bolt hole aligns with associate valve cover perimeter bolt hole.

Step-by-Step Instructions for Installing the Valve Cover Mounting Bolts:

Install the 20 Valve Cover Mounting Bolts:
First, begin by installing the 20 mounting bolts that secure the valve cover to the engine. These bolts are divided into two groups:

16 perimeter bolts located around the outer edge of the valve cover.
4 center bolts positioned in the middle section of the cover.

Next, use a 10mm socket (3/8″), a 3/8″ ratchet, and a socket extension to install the bolts. Start by tightening the perimeter bolts, working your way around the cover in a crisscross pattern to ensure even pressure distribution. Then, move on to the center bolts, tightening them securely but being careful not to overtighten, as this could damage the valve cover gasket.

Finally, double-check that you have properly tightened and seated all 20 bolts. This step is crucial to prevent oil leaks and ensure the valve cover mounts securely.

By following these steps, you can ensure a proper and reliable installation of the valve cover mounting bolts.

Special Notes on Bolt Types:

The front center bolt (located near the vanos bridge) and the 4 center bolts are shorter than the others. Install these bolts in their correct locations to avoid over-tightening or damaging the components.

The rear center bolt has limited access. To install it, use a 10mm socket (3/8″) , a 1/2″ ratchet , and a 1/2″ to 3/8″ socket adapter with an extension if necessary.

Tighten the Bolts Evenly:

Tighten the bolts gradually, working back and forth across the valve cover. This ensures even pressure distribution and prevents warping of the cover.

Tighten each bolt until it bottoms out on the cylinder head, but do not overtighten at this stage.

Final Torque to Specification:

Using a 10mm socket (3/8″) , a 3/8″ torque wrench , and a socket extension , fully tighten all bolts to the specified torque value:

8 Nm (6 ft-lb) .

Double-check that you have evenly torqued all bolts to ensure a proper seal and prevent oil leaks.

Install valve cover ground wire w/ nut on valve cover rear most stud (picture) (10mm socket 3/8″ / 3/8″ ratchet).

Install each coil into original sparkplug well and mount with 2 nuts (10mm socket 3/8″ / 3/8″ ratchet & extension). Rotate between coil mounting nuts to mount coil evenly.
Note: Coil boot will not fully insert onto sparkplug during initial mount. This is normal.
Fully tighten, 10Nm (7 ft-lb) (10mm socket 3/8″ / 3/8″ torque wrench & extension).

Reinstall Coils Cables/Bracket/Boot onto Valve Cover:
First, rotate the coil cables, bracket, and boot back into their original position on the valve cover. Next, mount the rear boot rubber block of the coil cables onto the valve cover. To do this, carefully slide the rubber block into the valve cover slot from the top, as shown in the picture.

Once you properly align the rubber block, securely seat it in the slot to prevent movement or dislodging during operation. Finally, double-check that you have correctly positioned all components and prepared them for the next steps.

Set Up Coil Cables Mounting Bracket:
First, prepare the coil cables mounting bracket by ensuring it is clean and free of obstructions. Next, align the bracket with the two mounting studs and carefully mount it onto them.

Then, secure the bracket in place by installing the two mounting nuts. To do this, use a 10mm socket with a 3/8″ ratchet and extension. Finally, securely tighten the nuts to firmly attach the bracket and prevent movement during operation.

By following these steps, you can properly set up the bracket and prepare it for use.

Step-by-Step Instructions for Installing Coil Cable Electrical Connectors:

Prepare the Coil Cable Connectors:
First, ensure that all coil cable electrical connectors are clean and free of debris. This step is crucial because it ensures a secure and reliable connection later on.

Install Each Connector:
Next, for each coil, follow these steps in order:

Lift Up on the Metal Lock:
Begin by locating the small metal lock on the connector. Then, gently lift it upward to unlock the connector. This action will allow the electrical connection to be made in the following step.
Press in the Electrical Connector:
After unlocking the connector, firmly press the cable’s electrical connector into place on the coil. Make sure it is fully seated to avoid any potential connection issues.
Push Down on the Metal Lock:
Once the connector is securely in place, push the metal lock back down to lock the connector in position. As a result, this ensures a tight and reliable connection that won’t come loose during operation.

Route the Coil Cables Properly:
Finally, after securing all connectors, carefully route the coil cables as needed. Ensure they are positioned away from moving parts, heat sources, or sharp edges to prevent damage or interference. Additionally, double-check the routing to confirm that the cables are not under tension or at risk of being pinched.

By following these steps, you can ensure a safe and effective installation process.

“Install Engine Top Cover
First, align the engine cover and carefully place it over the valve cover. Next, ensure that the rear left side of the cover mounts over the coil cable boot rubber block. Once aligned, press down firmly on the rear of the cover to fully mount the block. Then, proceed to install the four mounting bolts using a 5mm hex bit socket with a 3/8″ ratchet.

Installation of Fan & Shroud
Afterward, move on to the installation of the fan and shroud. Specifically, follow the steps for the Euro E36 M3 fan and shroud installation. Finally, once everything is securely in place, complete the post-repair procedures to ensure all components are functioning correctly.”

Allow sealant to dry a minimum of one hour before driving car.

Check and replenish engine oil.
Drive car, then park car and let engine oil settle.
Remove oil dipstick; wipe dipstick end; fully reinsert dipstick; remove dipstick again; read oil marking. If oil is low add needed (small) amount of new oil at oil fill cap at valve cover.