Viscous Fan Problem

Found my P38 Diesel to suddenly be noisy, especially in lower gears when on higher revs.

Was advised that I should check the viscous fan is working correctly. Found the fan was almost seased and hence running constantly. Had a couple of hours trying to take this off but gave up in the end. The cowling cannot be taken off with the fan in situ to give access or you have to take off the radiator, oil cooler etc.

Have bought the correct spanner that fits the fan but found that the fan just turns ... do I need another tool or is there an easier way?


Stuart Parker
2.5DT P38

are yer tryin ter undo it the right way?
most are left hand thread.

Yes.

I tried to jam a screwdriver between two bolts on the pulley but this did not work.

Stuart

I usually just stick a big philips screwdriver in the hole to stop it turning.

The problem is that there is no hole to stick a big screwdriver in. Access is very poor hence today I have taken out the radiator and cooler for the turbo to get access to the fan.

I have also tried to find the special tools mentioned in the manual ... I have the spanner to fit but cannot seem to get hold of the tool to hold the pulley.

Any suggestions on where I can get on to fit the pulley on the BMW 2.5 diesel engine?

Stuart Parker

Just clamp a pair of mole grips onto the pulley and turn it until it jams up up against the engine block.

Stuart, to remove the fan, drain the rad. & keep the antifreeze, remove the two hoses at the top, the plastic shield over the fan & anything else in your way.

You will need a large expanding (water pump) pliers, Draper do one fairly cheap (& they a great for pushing pistons back into the callipers, removing spin off oil filters etc.) grip the fan pulley with the pliers & undue the fan with your spanner, it’s tight.

When loose (& got a sweat on) remove the fan with the radiator cowl (2 x bolts & lift out of the peg holes at the bottom) when all is removed, place them both in a corner somewhere, like I have done two years ago & the engine runs perfect even in traffic on the hottest day. With the air con on if the temp requires it there are two huge electric fans that can blow for England behind the grill.

Now that you have this new found open area in view at the front of the engine, check the belts & pulley’s for wear & have a general clean up. The air con belt pulley can be opened up, clean the bearing, re grease, replace the seal & it will give it more longevity.

It now runs quieter, smoother & more mpg.

Regards Trevor2

Sorry "undo" not "undue"

Trevor2

hi folks,lookin to renew my ailing viscous fan on my 2.5dse..p38..does the petrol one fit ,or any other i can strait swap with,,,ta,,,,

No need to remove rad at all fan and shroud come off together. Correct spanner on fan nut and a sharp tap on spanner with a hammer is all that is needed. You will never undo it just by trying to turn it with spanner. Unclip shroud and unscrew fan and they come out together. Fans always undo in the direction they turn.

Wammers on the ball as usual.

All the DSE's are a left hand thread. Get the spanner in place on the nut horizontal on the diesel pump side of the engine, put a big screwdriver across the nuts holding the waterpump pulley in place. Then give the spanner a sharp whack with a suitably heavy implement. It might take a few go's but it will come off.

Also the shroud is way more durable than you think, If the engine is anyway warm when you are doing this the shroud will bend enough to give good access to take the fan out without removing anything if you had to. The shroud will then come out with the fan.

Trevor2 said:

Stuart, to remove the fan, drain the rad. & keep the antifreeze, remove the two hoses at the top, the plastic shield over the fan & anything else in your way.

You will need a large expanding (water pump) pliers, Draper do one fairly cheap (& they a great for pushing pistons back into the callipers, removing spin off oil filters etc.) grip the fan pulley with the pliers & undue the fan with your spanner, it’s tight.

When loose (& got a sweat on) remove the fan with the radiator cowl (2 x bolts & lift out of the peg holes at the bottom) when all is removed, place them both in a corner somewhere, like I have done two years ago & the engine runs perfect even in traffic on the hottest day. With the air con on if the temp requires it there are two huge electric fans that can blow for England behind the grill.

Now that you have this new found open area in view at the front of the engine, check the belts & pulley’s for wear & have a general clean up. The air con belt pulley can be opened up, clean the bearing, re grease, replace the seal & it will give it more longevity.

It now runs quieter, smoother & more mpg.

Regards Trevor2

Click to expand...

I can give you a mod to automate the aircon fans to cool the engine PM me with an email address if you are interested.

SpudH said:

Wammers on the ball as usual.

All the DSE's are a left hand thread. Get the spanner in place on the nut horizontal on the diesel pump side of the engine, put a big screwdriver across the nuts holding the waterpump pulley in place. Then give the spanner a sharp whack with a suitably heavy implement. It might take a few go's but it will come off.

Also the shroud is way more durable than you think, If the engine is anyway warm when you are doing this the shroud will bend enough to give good access to take the fan out without removing anything if you had to. The shroud will then come out with the fan.

Click to expand...

Not unless you remove the rad hoses on the diesel as far as I can see

I didn't say remove the "rad". To make life easy with a "really tight" fan, drain the rad & remove the 2 x top hoses (diesel engine) this way you can lift out the cowl & get at the fan easier? Draper Tools do a cheap fan hub holding tool & the correct spanner for the fan nut.

Travis.

Undo the hoses to the top of the rad & secure to one side, then follow instructions from wammers/spudh. Viscous nut is 32mm.

I had horrendous problems getting the viscous fan off my diesel. It hadn't been off in 11 years and just wouldn't budge. I ended up unbolting the water pump and I then lifted the fan and pump out in one piece along with the shroud. Had to clamp it in a large vice and whack the spanner with a big lump hammer to get it off.
Needless to say I put lots of copperslip on the new one. I also did a mod to the shroud to allow easy access in the future. I cut the top off with a band saw and made up some clips to hold it back in place.