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View Full Version : Bad fan clutch?


ree
03-30-2006, 03:52 PM
Last fall I started noticing a whine/whoosh from engine that increased as I accellerated and stayed pretty constant at speed. It went away during the winter and the dealer could not reproduce the noise when I had it in then. Now with temps rising into upper 40's and above it's back.

From my h2source research it sounds like maybe the fan clutch staying engaged all the time.

Is there an easy way for me to tell if this is the case? e.g. can I watch the fan speed at cold start versus when it's running warm at idle with the hood up and reach any conclusions about whether it needs to go to the dealer?

Planohummer
03-30-2006, 04:35 PM
On a cold start(truck's been sitting overnight) you should be able to hold the fan blade while the engine starts(grab hold of fan blade BEFORE having your buddy cranking engine). If the clutch is stuck you won't be able to hold it.
****disclaimer-this advice is worth what you paid for it. Any body damage or missing digits is not anyone on this forum's responsibility.

Fastest H-Town Realtor
03-30-2006, 04:42 PM
If the clutch is stuck, you will not be able to move/have a real difficult time of moving it even if the engine is off...Not to sure i would grab the blade and crank the starter.

The engine will rev up/down slower than if the clutch were good/free. The noise is unmistakeable.

ree
03-30-2006, 04:54 PM
And if it's stuck, but only after the engine compartment is slightly warmed up try check it with cold engine when it's warmer out?

Any idea at what air temp it's suppose to lock if working to spec?

ree
03-30-2006, 04:57 PM
BTW, it turns easily at 55* F with cold engine.

ree
03-30-2006, 07:37 PM
And I did an experiment. I started it and let it idle to warm up. When the coolant temp need started moving off the 160 mark, I'd slowly rev it up and the fan speeds up in sync with the RPMs until about 2200 RPM when it's roaring pretty good. Then if I increase RPMs a bit more the fan slows some. I did this until it hit a normal operating temp of 210.

Is this normal operation?

It's not obviously broken and engaged 100% of the time. I'll do more experiments after it get's nice and warmed up on a longer drive. I think when it's warmer the fan clutch stays engaged more/most of the time.

partsguy
03-31-2006, 02:45 PM
You ever notice the warning signs on the fan shroud?

Would not do that on a dare.

Fastest H-Town Realtor
04-01-2006, 02:30 AM
Originally posted by partsguy:
You ever notice the warning signs on the fan shroud?

Would not do that on a dare.

Unless you have a case of beer..some duct tape...and a video camera...maybe an emergency medical kit. http://www.elcova.com/infopop/emoticons/icon_wink.gif