Failed Viscous coupling fan

[Big Brin]

I have recently acquired a fantastic 330Ci. It is great in every way, except that last weekend it overheated on the motorway. I stopped in traffic and the temp gauge just marched into the red and then the light came on. I had to stop, turn off and wait for recovery. The car works fine, execpt when it gets into traffic and has to idle for a long period. I think that the fan is receiving a signal to start when the temperature gets high, but the fan doesn't want to start. (I say this as with the bonnet up, the fan attempts to move.) I have got the car booked in on Monday, and they will do the diagnosis, but as the fault appears to me to be intermittent, I don't want to get the car back with na 'no fault found' concusion.

Anyone in Beamer land had a similar problem? And what was the cause?

Appreciate any advice.

Rgds, Big Brin

[weed]

Do you have a fan on the end of the engine?
If so, roll up a newspaper and try to stop the fan.
If the fan stops relatively quickly, the fan clutch is knackered. A good clutch fan will shred it so keep your mitts and dangly jewelry clear.
the electric fan, seems not to be working either. It should be energised when you switch on the AC...check it out.
If it does not, see if you can locate the fuse that protects the fan circuit 20-30A probably, and replace it.
If you still cannot energise the electric fan with the AC on max cool, then it could be failed relays and/or failed thermoswitch. You'll have to take it somewhere.
m.

[Big Brin]

Thanks for the info. and the tips. The fan didn't move at all. So no need to keep by 'bits' out of the way. The diagnosis from the BMW garage was that the fan had failed completely and now, following replacement it is working great. Cost a bob or two, so I'll have to look out for an independant BMW specialist in the south who can do any 'minor' (non service) works at less than the main dealers charge.

Rgds, Big Brin