fan clutch

Messages
69
Likes
0
Location
Toronto
#1
Can anybody explain how the viscous fan clutch works on the cooling fan?
I was told that the fan should be more difficult to spin by hand when the clutch is warm( at operating temperature)!!
Mine doesn't, so this might explain part of my high engine temp problem.

Thanks.
 
Messages
1,271
Likes
5
Location
Toronto, Canada
#2
I've not heard that before, and I don't know how they work. Have you ruled out all other possible options? Water pump, thermostat, coolant level, etc? Your best bet would be to call Chuck at Chuck's Auto in Rexdale (416)749-9211 (you probably know him). He should be able to confirm that for you, and if that's the problem, he'll probably have a bunch of used ones in his parts shelves.
 
Messages
166
Likes
0
Location
Florida
#3
The fluid inside gets thicker as the temp gets hotter. So yes, at higher ambient temps, the fan will pull harder (or slip less, however you want to say it) and pull more air through the grill. Over time, I have heard that the fans can develop minute cracks that slowly allow the fluid to seep out thus eventually causing failure.

On a really hot day at operating temp, the thing should be able to take your hand off, so don't stick it in the way. However, when you first start up on a cool am, you should be able to hold the fan from spinning at all.

Best to tests when engine is off. If really hot, you will not be able to spin it very easily. It will be very free when cooler.
 
Messages
69
Likes
0
Location
Toronto
#4
Thanks for the responses.
Chuck is a great BMW guy but he is so damn busy. I did call him and this is the second day waiting for a response.
 


Top