E46 Mechanical Fan & Shroud Procedure

The following information is provided for reference purposes only and should be used at your own risk
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.

Fan & shroud removal

Open front hood.

E46 Mechanical Fan & Shroud
Remove 3 rivets at top of air intake duct at top of radiator.
For each rivet, pry out rivet center pin (tack lifter), then pull up on rivet to remove.

E46 Mechanical Fan & Shroud
Disconnect air intake duct from air filter housing.
Press in on duct fore and aft at filter housing to release duct tabs, and pull duct out of filter housing.

Remove intake air duct from engine bay.


Disconnect AUC (smell) sensor and fan electrical connectors at top left of fan shroud.
Press in on AUC sensor electrical connector top clip and pull out electrical connector.
Press in on fan electrical connector side clips and pull out electrical connector.

E46 Mechanical Fan & Shroud
Start by removing the fan electrical connector cable from the fan shroud clip.

E46 Mechanical Fan & Shroud
Next, take out the fan shroud mounting bolt located at the top left of the fan shroud (using a T25 torx bit socket and a 1/4″ ratchet).

E46 Mechanical Fan & Shroud
Finally, remove the rivet at the top right corner of the fan shroud. Pry out rivet center pin (tack lifter), then fully pry out rivet from base (tack lifter).


Remove fan, belt static friction method.
Remove fan / fan clutch from water pump shaft.
Place open wrench on fan clutch nut (32mm combo wrench). Place wrench forward on nut to avoid hitting vanos body and thermostat hose connector. Strongly strike wrench side at top with heavy hammer to break nut seize (sledge hammer); left hand thread.
Note: Nut is left hand thread, thus unscrew by hitting wrench top from left to right (car front orientation). Serpentine belt static friction on water pump pulley facilitates large enough opposing force to break nut seize. It is important to use a heavy hammer to produce a high instantaneous jerk. Several attempts will be needed before nut seize breaks. Rotate open wrench to reposition for better access.

If belt static friction method is not successful, attempt pulley holding tool method.

E46 Mechanical Fan & Shroud

E46 Mechanical Fan & Shroud

  1. First, remove the fan using the pulley holding tool method.
  2. Next, detach the fan and fan clutch from the water pump shaft.
  3. Then, position the water pump pulley to allow access for the holding tool. Note that the water pump pulley has two adjacent pairs of mounting bolts. To do this, align one of the bolt pairs so the left bolt is just to the right of the top center (refer to the picture) using a 32mm combo wrench.
  4. After that, install the water pump pulley holding tool onto the pulley bolts. Position the holding tool to the right, and place the tool’s indent curve against the fan clutch nut. Mount the tool’s end hole onto the pulley’s bottom left bolt and the tool’s second hole onto the pulley’s right bolt. If needed, reposition the fan clutch nut for better access to the holding tool (refer to the picture).
  5. Finally, place an open wrench on the fan clutch nut (32mm combo wrench). Counter-hold the holding tool and break the clutch nut’s seize (remember, it’s a left-hand thread) using the 32mm combo wrench.

Note: Nut is left hand thread, thus unscrew by turning wrench from left to right (car front orientation).

If fun clutch nut seize difficult to break, apply lubricant to nut/threads contact surfaces (spray lubricant).

Once nut seize is broken, remove tools and spin fan blades to unscrew nut; left hand thread.
When nut is close to shaft end, turn fan slowly while continuously holding fan blades. This will keep fan from falling and damaging radiator fins when fully disconnected.


Remove fan and fan shroud from engine bay.
Lift fan shroud up while maneuvering fan / fan clutch out of fan shroud and engine bay.
Remove fan shroud from engine bay.

Fan & shroud installation

E46 Mechanical Fan & Shroud
Install fan shroud in engine bay.
Align shroud by pulling up, forward, and dropping into position.


Insert fan/clutch in fan shroud. Lift shroud up and forward while maneuvering fan/clutch into shroud.
Note: Fan is oriented with clutch nut to car rear.
Align shroud by pulling up, forward, and dropping down into lower frame slots.


Mount fan/clutch onto water pump shaft.
Lift fan and mate (hang) fan clutch nut onto water pump shaft. Rotate fan to find best nut thread to shaft thread mate. At optimal fit, fan will hang on shaft without threading (picture).
With fan hanging independently on shaft, slowly turn fan blades to thread nut onto shaft; left hand thread. Fully thread nut onto shaft


Place open wrench on fan clutch nut (32mm combo wrench) and lightly hit wrench top with heavy hammer, one time; left hand thread (sledge hammer).
Note: Serpentine belt static friction on water pump pulley facilitates large enough opposing force to tighten clutch nut. Fan opposing spin also tightens fan clutch nut.


Install rivet at top right corner of fan shroud. Pry rivet center pin out, fully insert rivet base into shroud, then press in rivet center pin.


Install fan shroud mounting bolt at top left corner (T25 torx bit socket 1/4″ / 1/4″ ratchet).


Install fan and AUC electrical connectors.
Insert each connector until clip “click” sound is heard.
Insert fan electrical connector cable into fan shroud clip.


Install air intake duct on top of radiator.
Insert duct into air filter housing until tabs insert into slots.


Install 3 rivets at top air intake duct. For each rivet, pry rivet center pin out, fully insert rivet base into air intake duct, then press in rivet center pin.

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