clutch fan

[aaadave]

hello all, I have an 01 ram 5.2. when cold, the clutch fan will spin fast like it is locked up. when it gets hot, it will almost completely stop spinning. thought is was a bad clutch so bought a new one. does the same thing. all this is at idle and does not change with engine speed. if it idles long enough it will finally start to over heat. my way of thinking is that it should stay engaged all the time at idle. am I missing something? again this is a brand new hayden clutch. thanks, dave.

 

[rowdyram]

They will typically drag more when cold to load the engine and aid in warmup and most will be almost fully locked in for about 30 seconds after start up. As it spins for a while it should loosen up. Most fan clutches also do not fully lock at idle regardless of temp because it will bog the motor. There is a centrifugal valve on the drive side that has to spin fast enough to close to allow the fluid to move through the vicious drive to lock up.

It does seem odd you say it almost stops when hot. Everyone has a different definition of almost I guess.
I think your clutch is probably OK. If you hold it at 2k rpm hot does it seem to spin faster?

Does your t stat open? Is the passenger side of your radiator hot?

If your radiator isn't getting hot the fan clutch will not get hot either

 

[aaadave]

thanks rowdy ram, when idleing hot, you can just about count the blades as they turn. if It idles long enough, it will finally run hot and you have to shut it down. revving up the rpms have no effect on fan speed. you can shut it down while hot and spin the blades by hand with no resistance at all. clutch doesn't have but maybe 100 miles on it. beats all I've ever seen. the way parts are these days, the new one's probably bad. dave.

 

[rowdyram]

Oh yes, if there is no resistance and it spins that slow yes it is most definitely not right.