Fan clutch

So, my car was close to overheating last week when I was at an idle, the fan clutch, I think is original, and has been giving me signs of rising temps at idle for a few months. Today I put a new one in and the temps are better at idle but if you shut the car off when its warmed up and at operating temperature and quick go turn the motor fan there's no resistance (like the old one).

I would have thought the clutch would get stiffer if the engine temp is rising at idle, or is the role of the clutch more at speed (which is fine)?

If you're sitting there at idle and the temps are creeping up(my car runs dead in the middle) to almost 3/4 you can bring it down by a fast idle, say 1000. It will then go right down, just as it would when you start to drive/move.

I've always thought the fan clutch was there to uncouple at higher speeds creating less drag....

Thanks, Rick

Idle speed should give a noticeable fan speed. On thing you might do is take a little risk and put a gloved finger against the fan blade with the engine at idle. If you can easily stop it then it is not giving the torque it needs. Be careful though, as the temp increases, the torque could suddenly change.

Reving the engine and watching how much air comes off the fan is a good way to tell what it does when at 1000 rpm.

My fan runs at a low speed no matter what the engine is doing but the radiator has enough capacity that it does not overheat until the OAT is about 100F.

Bob in Lake Havasu

Quote
Bob in Everett
Idle speed should give a noticeable fan speed. On thing you might do is take a little risk and put a gloved finger against the fan blade with the engine at idle. If you can easily stop it then it is not giving the torque it needs. Be careful though, as the temp increases, the torque could suddenly change.

Reving the engine and watching how much air comes off the fan is a good way to tell what it does when at 1000 rpm.

My fan runs at a low speed no matter what the engine is doing but the radiator has enough capacity that it does not overheat until the OAT is about 100F.

I think we use the newspaper test at idle Bob. I blew out the ac condenser and the radiator (the radiator is 20k old) when I did the fan clutch today but I couldn't get the thermostat housing bolts loose, so the new thermostat will have to wait.

There's one thing about the fan clutch that I remember from the old forum, they used to be packed and stored standing vertical and when you got ready to install you gave them a day vertical to get all the fluids in the right places. The clutch I just got didn't have any of those warnings, but it should be interesting to see what happens tomorrow.

So, a few days into testing this bird and things have started to normalize (to some degree. I have to order a new housing for the thermostat. I'm hoping the housing is not part of the intake manifold.

At least then I'll have a cooling system I can relate to; everything new or not too old...