Hi again to friends old and new! it's been a while since I have been on the forum, getting older and don't seem to have enough time to keep up with life as it seams. But I sure could use your help right now. I am trying to determine what metallic engine squeal I am hearing when at rpm's over 2000 while parked and just reving up the engine. It also happens when driving down the highway and I start to build 5-10 lbs of boots.

Its sort of a high pitched metalic squeal that only presents itself after the engine is warm on our 2003 F-250.

Just took off the old Van Turbo and replaced it with a KC300x 63/68. Squeal still present. So it's not the turbo itself.
replaced all the boots and did a pressure test with a boot tester up to 20 lbs - no squeal - so I assume the boots are good

I am really wondering if it could be the fan clutch. But I cant recall the normal fan clutch operation. I recall the clutch fluid must reach about 200 degrees before locking the clutch in, or something like that.

My question is - ----with a cold engine should the fan spin relatively free or with some minimal resistance or enough resistance to make it feel like dragging your dog by the leash after they see a squirrel? Right now I have to apply quite a bit of force to get my fan to move when the engine has sat overnight and is cold. I though it should spin relatively easily on a cold engine.

Thanks ahead of time - and my apologies for being a ghost on the forum.......

Rich

 

Heat gun says 80 degrees and I really have to put some force into it to get her to move. At least 10-15 lbs of pushing.

 

I would be more likely to suspect a bearing in the alternator, idler pulley or the belt tensioner then a fan clutch, only because I have never heard a bad clutch make a metallic noise. But that is exactly the noise a failing bearing makes.

 

Both my trucks, when cold, take an ungodly amount of force to turn the fan...went thru same question 8yrs ago. Ordered new oem clutch and results were the same...tensioners and pulleys are cheap to replace and are a value to have as a spare

 

Get it warm to the point where you get the squeal....shut it down and remove the belt. Start it, listen for the squeal. My guess is that the tensioner or idler pulley bearing is getting ready to leave this earth.

I recently had a idler bearing on a Case 1845c skid loader give up. I ordered a new bearing, new water pump, idler and belt. Had a problem with delivery of the pump and idler. I needed the machine so I put it back together with the old idler and pump.

It had a squeak like you describe. When the new pump and Idler came in...I put them in.....quiet as a church mouse now. The fan got loose and whacked the idler, enough to bend it so the belt was squeaking on it.

You can diagnose a belt squeak with a spray bottle of water.

 

Thank you gentlemen for the fast replies. Will check out your recommendsations and report back.....We are getting ready to get about a foot of snow starting tomorrow. I’ll get as much done as I can,

 

Interested to hear what you find.

Looks like it's pretty typical for fan clutches to start out engaged when cold (still slip a little, but explains the stiffness), then mostly release after several seconds when rev'd a bit to move the clutch fluid around and disengage. Attached Hayden pdf with info.

 

As others have said, my fan/clutch take a good amount of force to move when cold.

I was going to suggest something very similar to what Dan V posted.

 

OK gentlemen, here’s what I have observed so far. When I tried to move the fan clutch this morning the temperature gun said 62° On a cold engine that sat overnight. I had to pull with a very large amount of force to get the fan to turn. If I use two or three fingers to do it I would put a deep crease in my finger tips to the point of almost breaking the skin.

 

It actually hurts if I only use two or three fingers. I have to grab the fan blade with four fingers or my whole hand and that still hurts some without gloves on. Drove it around to a friends house to help him with his 2002 excursion fuel pressure problem. Engine reach normal operating temperature turn the truck off waited five minutes and the temperature probe said 120° On the fan clutch assembly. I still Needed the same amount of pressure to turn the blades as I did this morning on a cold engine.

When I checked the fan blades on his excursion, they would easily move with a few pounds of force and I could do it easily with two fingers. A huge difference from my cold engine experience this morning.

Drove it home, still breaking in the new turbo so I did not get her too hot - but the fan clutch assembly read 95° on the heat gun. Still the same amount of resistance trying to turn the fan.

 

Whether or not this is where my high pitch squeal is coming from over 2000 RPMs, the fan clutch does not seem to be operating correctly. When somebody gets the chance could you verify how difficult it is to turn the fan blades on your 7.3 L and see how much resistance it takes .

best regards - Rich

 

Push the fan blades back and forth - if there is any play, the squealing is likely coming from the water pump.

When I bought my truck in San Antonio in 2014, I was stuck in traffic on the way back and I was driving slowly next to a large truck. I could clearly hear a squealing noise that I thought was a u-joint going south. Turns out it was the water pump, as I found out when I got closer to home.

Good to see you on here Rich!

 

If the fan clutch is locked...you would hear the roar of the fan pulling air. Mine feels like you are dragging something through pudding.

 

I would forget about the fan clutch for now and focus on other possibilities. I really don't think a fan clutch can make any noise.

 

Thank you very much Dan, if yours is like pudding mine is like climbing up one of those old ropes in the high school gymnasium. And this is at 60 degrees, 80 or 120