Viscous Fan Clutch, need fault confirming

Post Fri Oct 14, 2005 11:31 pm

OK heres the deal............

M20B25
Cold Engine = Fan spun by hand easily, very little resistance = NORMAL
Hot Engine = Fan spun by hand easily, very little resistance = FAULTY

Is this correct ?

There is no (detectable) difference is the viscous fan clutch resistance between a hot or cold cooling system.

Post Fri Oct 14, 2005 11:47 pm

if u can stop the fan easly while engine at temp then it needs replacin

Post Sat Oct 15, 2005 12:38 am

A little unsure about the 2.5i's, but if it's the same as 318is, then is it not the Viscous Fan Coupling that needs replacing?? I had the same problem and replaced the coupling and bingo!! Good as new!!

Post Sat Oct 15, 2005 1:20 am

Dont mean to hijack your thread, but my viscous sounds like a jumbo jet.It seems to be over working, could it possibly be locked somehow?

Post Sat Oct 15, 2005 4:30 am

It's probably not on there correctly, if it's new....If it's not, then it might have been put on to tight, which would be difficult to do as it's reverse thread..try taking it off and putting it back on again, checking out the coupling when you take it off.

HTH

Post Sat Oct 15, 2005 8:55 am

Sounds right, if the fan is easy to move when the engine is very hot, then it's faulty, all E30's shared the same viscous coupling.

If your viscous is wooshing constantly at any temp even low temps, then again this is faulty and needs replacing.

Post Sat Oct 15, 2005 9:21 am

The test is, with the engine running hot, stick your fingers into the blades of the fan.
This will show that there is definitely something wrong with your brain.

Post Sat Oct 15, 2005 9:23 am

SwirlyE30- could be the water pump on the way out. Check for a leak from the little aperture on the pump. Any leaks, swap the pump. The pumps are pennies really, best swap it.

Post Sat Oct 15, 2005 9:28 am

How easy is it to swap the pump with no fingers left?

Post Sat Oct 15, 2005 10:13 am

kam-325i wrote:OK heres the deal............

M20B25
Cold Engine = Fan spun by hand easily, very little resistance = NORMAL
Hot Engine = Fan spun by hand easily, very little resistance = FAULTY

Is this correct ?

I think you're propbably looking for a fault that doesn't exist.
The fan should spin easily by hand with the engine hot or cold. It should only lock up on an engine which is beginning to overheat.
Run the engine with the car parked and watch the temp gauge. If it does not go up past normal, then your viscous coupling is probably working OK.
You should be able to hear when the fan cuts in by the extra noise.

Post Sat Oct 15, 2005 1:02 pm

Brianmoooore wrote:
kam-325i wrote:OK heres the deal............

M20B25
Cold Engine = Fan spun by hand easily, very little resistance = NORMAL
Hot Engine = Fan spun by hand easily, very little resistance = FAULTY

Is this correct ?
I think you're propbably looking for a fault that doesn't exist.
The fan should spin easily by hand with the engine hot or cold. It should only lock up on an engine which is beginning to overheat.
Run the engine with the car parked and watch the temp gauge. If it does not go up past normal, then your viscous coupling is probably working OK.
You should be able to hear when the fan cuts in by the extra noise.

I am having a overheating problem, sat in traffic, temp rise's considrably, start normal driving again, temp come back down to normal.

Post Sat Oct 15, 2005 1:44 pm

don't forget to do as mentioned before and check the water pump. I had a problem like yours and found out just in time that it was the water pump. You do not want to have that die on you and your engine overheat cause of no cooling.

Cheers

Post Sat Oct 15, 2005 10:13 pm

kam-325i wrote:
Brianmoooore wrote:
kam-325i wrote:OK heres the deal............

M20B25
Cold Engine = Fan spun by hand easily, very little resistance = NORMAL
Hot Engine = Fan spun by hand easily, very little resistance = FAULTY

Is this correct ?
I think you're propbably looking for a fault that doesn't exist.
The fan should spin easily by hand with the engine hot or cold. It should only lock up on an engine which is beginning to overheat.
Run the engine with the car parked and watch the temp gauge. If it does not go up past normal, then your viscous coupling is probably working OK.
You should be able to hear when the fan cuts in by the extra noise.
I am having a overheating problem, sat in traffic, temp rise's considrably, start normal driving again, temp come back down to normal.

In that case, the viscous coupling is almost certainly duff.