E39 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

From under car

Raise front of car and place on jack stands (follow appropriate procedure; chock both sides of both rear wheels).
Note: Work under car can be performed without raising car, but will be under tight space.


Remove large engine compartment shield underneath front of car (Philips).


Disconnect coolant hoses from fan shroud bottom. Note hose mount sequence for reinstallation.


Disconnect auxiliary water pump electrical connector at bottom corner.
Disconnect coolant hoses from fan shroud side.


Slide pump out of fan shroud sleeve. Keep horizontal hose in shroud clip to allow pump to slide strait out. Once pump is out of shroud sleeve disconnect hose from shroud clip.
Note: Some coolant will leak from coolant hose connectors when manipulating them.

Lower car from jack stands (follow appropriate procedure).

From top of car

Open front hood.


Remove AUC (smell) sensor from fan shroud right side.
Press in on electrical connector side clip and pull up electrical connector. Move electrical cable/connector to side.
Push up on AUC bottom and pull top away from shroud. Push down on AUC top and pull bottom away from shroud. Remove AUC sensor from engine bay.


Remove rivet at each top corner of fan shroud. Pry out rivet center pin (tack lifter), then fully pry out rivet from base (tack lifter).


Remove retaining plastic clip at expansion tank bleed crew. Press in at both wings and lift up (2 flatheads).
Note: Unscrew/re-screw expansion tank cap as needed to remove clip.


Remove rubber seal between fan shroud top and car frame (hand).
Note seal orientation for reinstallation.


Lift fan shroud up and to rear.
Unscrew overflow hose clamp at radiator right top (Philips).
Pry hose off radiator overflow neck (flathead).
Remove hose clamp from hose to keep from loosing.

Note: If overflow hose clamp original, pry open clamp to remove (small flathead) and replaced with adjustable hose clamp.

Place fan shroud back into install position to facilitate space for fan removal.
Lift fan shroud up, pull forward, and drop down to mount into lower frame slots.


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.


Pulley holding tool method:
Remove fan / fan clutch from water pump shaft.
Position water pump pulley for holding tool access. Water pump pulley has 2 (adjacent) pairs of mounting bolts. Position one of the bolt pairs with left bolt at just to right of top center (picture) (32mm combo wrench).
Install water pump pulley holding tool onto pulley bolts. Position holding tool at right, and place tool indent curve against fan clutch nut. Mount tool end hole onto pulley bottom left bolt, and tool second hole onto pulley right bolt. Reposition fan clutch nut for better holding tool access (picture).
Place open wrench on fan clutch nut (32mm combo wrench). Counter hold holding tool and break clutch nut seize (32mm combo wrench); left hand thread.
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.


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


Remove fan shroud from engine bay.
Remove expansion tank bleed screw, dislodge expansion tank from fan shroud, then reinstall bleed screw (Philips).
Pull up on fan shroud while removing expansion tank and hoses from shroud. Tilt fan shroud right side up to help removal. Pull out overflow hose from shroud access slot. Remove shroud from engine bay. Place expansion tank at high location in engine bay. Place overflow hose high to keep coolant from draining out.
Note: Coolant will leak out from radiator overflow hose. Keep expansion tank height low to minimize leakage.

Fan & shroud installation

From top of car


Install fan shroud.
Position expansion tank at engine bay left side to mate with fan shroud.
Tilt shroud right side up and slide shroud into position while attaching expansion tank to shroud.
Insert expansion tank overflow hose into shroud access slot and lay on top of radiator.
Remove expansion tank bleed screw (Philips), fully install expansion tank onto shroud, and reinstall bleed screw (Philips).
Align shroud by pulling up, forward, and dropping into position.


Insert fan/clutch in fan shroud. Lift fan shroud up and forward while maneuvering fan/clutch into fan 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.


Lift fan shroud up and to rear. Insert overflow hose clamp onto overflow hose with clamp bolt head at bottom and facing forward (picture). Mount overflow hose onto radiator overflow neck. Position hose clamp onto radiator overflow neck and tighten clamp (Philips). Note: Position clamp bolt at bottom of radiator neck to allow for proper fan shroud fitment.


Fully install fan shroud. Lift fan shroud up, pull forward, and drop down to mount into lower frame slots.
Note: Fan shroud should insert fully and align with car frame.


Install rubber seal between fan shroud top and car frame.


Install retaining plastic clip at expansion tank bleed screw. Push down clip until it snaps in.
Unscrew and re-screw expansion tank cap as needed to facilitate access.


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


Install AUC (smell) sensor onto right side of fan shroud. Place sensor at mount position on shroud. Push down from sensor top and insert bottom clip, then push up from sensor bottom and insert top clip.
Install AUC electrical connector.

From under car

Raise front of car and place on jack stands (follow appropriate procedure; chock both sides of both rear wheels).
Note: Work under car can be performed without raising car, but will be under tight space.


Insert auxiliary water pump into fan shroud sleeve at bottom left side. Insert horizontal hose in shroud clip to allow pump to slide strait in.


Install auxiliary water pump electrical connector.
Install coolant hoses on fan shroud at left side.


Install coolant hoses on fan shroud at bottom side.


Install large engine compartment shield underneath front of car (Philips).

Lower car from jack stands (follow appropriate procedure).


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