M20 Viscous Fan Change

[M3KUK]

Hi, do I have to remove the water pump to change the Viscous Fan unit? The fan on my Convertible is whooshing as if it's on all the time. Ta Mike.

[Topblag]

Nope.

[Brianmoooore]

No. Viscous coupling is screwed onto the nose of the pump with a REVERSE thread.
You need a long 32mm thin spanner and a hammer to remove it. Position the spanner vertically down onto the 32mm nut, and smack the other end of the spanner with the hammer to the right, while looking towards the back of the car. This should shock the nut loose, and allow you to wind off the fan. The new coupling only needs to be nipped up the slightest amount. It does not need thread locking compound or torquing up. It will not come loose or fall off.
If the coupling will not shock loose, you need a piece of 25mm x 2mm steel bar by about 200mm, drill a 6.5 mm hole as close to one corner as possible, remove one of the 6mm bolts holding the pump pulley in place, then bolt your steel bar in place, using a slightly longer 6mm bolt. If you use the original, you WILL strip the thread in the pump flange.
Use the 32mm spanner to turn the pump pulley, until the bar lacks against the side of the pulley, then, holding the bar to stop the pulley turning, proceed as before to smack the spanner.

[paultv]

Original Viscous coupling: remove radiator top mount (2 bolts into plastic clip thingy) lift radiator and move forward as far as you can - fan and coupling will come out with a wriggle - a lot of after market units are slimmer, and easier to fit - I've had one that never allowed free spin when cold or at all, always solid, useless, so I suggest that you buy the OEM replacement.

Paul

[M3KUK]

Awesome, thanks!

[M3KUK]

Got it off tonight, in fact I took 2 off as I swapped the good one off my 325i onto the Convertible. You can tell it's knackered by spinning it.