1985 323i VISCOUS FAN

[Tim64]

Hi all,
Am I correct in thinking that once my car is up to running temp (needle in the middle of the gauge) if you can stop the fan with a rolled up magazine it’s faulty ?
I tried the test on mine and it stopped very easily ! My car is due a new cambelt (would a genuine belt be the best option or anybody got any recommendations) and the water pump has a slight leak so would it be good practice to replace the fan at the same time ?
As always thanks in advance for any help,
Cheers Tim.

[Brianmoooore]

Am I correct in thinking that once my car is up to running temp (needle in the middle of the gauge) if you can stop the fan with a rolled up magazine it’s faulty ?

No. There's a lot of rubbish spouted about viscous fan couplings on the internet.
Fan should be easily stoppable when the engine is at running temp, since the only thing driving it is the friction of a ball bearing.
If you leave the engine idling, there may or may not be enough airflow provided by the fan to keep the engine at the correct temp., but if there isn't, and the temp begins to creep up, then the coupling should lock, and the fan will speed up to engine revs times whatever the ratio is between crank pulley and water pump pulley diameters. This will be very noticeable if you rev. the engine, when the fan will make a noise like a small plane on its take off run.
Mine seized solid near Monaco three years ago, and I had to put up with the racket all the way home.

[boiliebasher]

Also as far as I'm aware, what Brianmoooore mentioned above, the same basic principle goes for all viscous coupling fan in all vehicles.

For arguments sake, the fan won't lock up until the engine gets to something like 3/4 on the gauge. It should only really kick in if your sat in traffic or climbing a steep hill loaded up.

[Tim64]

Thanks for mate much appreciated