I have a 2001 F250 with the 7.3. Ever since I bought this truck with 83k on it, I have had a very high pitch squeal. This only happens when the clutch fan is engaged, ac on, as I'm pulling a hill the rps are at 2500. I get a very high pitch whistle/squeal out of the motor area. I had a Edge Evolution put in it so I could monitor the egt, trans, engine oil. along with new exhaust and intake.

I took this truck to ATS Transmission, right away they told me it was the turbo, $2,500.00 later a day later and same thing happened. Took it back, they had the truck for 2 weeks and said they changed out the fan blades, fan clutch, ac pump, alternator and they finally told me it was the water pump. Well, I told them that the pump was only 6 months old from ford. Anyway winter came, didn't drive it much and here we are again everytime I go camping and pull I get this noise.

What do I do? Sell it. I have heard nothing but bad about the 6.0

 

Moved from '80-'86 forum.

 

I am curious if you mean turbo whistle? It is very common for a belt squeal at n idle but not at any rpms.

Or maybe the EBPV is sticking on you and giving you a woooooshing sound?

 

Fan could be engaging because of pulling a load up a hill with ac on. The belt could just be slipping, might just want to replace and check all of your idler/tensioner bearings.

 

x2, this is the first thing that comes to mind.

 

What would the belt be slipping on? Not the fan. There is more surface area on that than anything else.

 

The serpentine belt gets hard with age and will squeal when heavy loads from alternator make it work harder.