I have 2000 F150 v6 4.2 5 speed manual 4X4. 179K miles. The truck has developed a squealing noise that i just cannot pinpoint. very faint noise at idle, but the squeal increases with rpms. I know its not the belt because i have replaced it. The alternator and power steering pump are very new.

The more rpms the more the squealing. The squealing noise is noticed at first start up but it doesnt go away when the engine is warm. Sometimes the squealing noise is not there at all....but briefly.

I did notice on one of the pulleys (idler maybe?) that there is some spots or black marks, like the pulley is hanging up and the belt is getting hot.....i dont know.

Please help me pinpoint the noise.....its driving me crazy!!!!!

 

are you sure its coming from the engine bay?

 

I'm thinking it could be the throwout bearing... maybe.

Or else a pulley is shot or out of alignment.

I know on mine, I had the A/C compressor replaced 2 times because the a/c clutch kept squealing when engaged. It could be that.

 

Does it squeal if you run it with the belt removed?

 

It is defininately coming from the engine bay. The squeal (or squeak) doesnt change when the wheel is turned or the a/c on or off.

glc....i cant run the engine with the belt off

 

Yes you can. A couple of minutes with no belt won't hurt anything and you need to do it to determine if the squeal is in a belt-driven accessory or not.

If you were to take it in to a shop, this is exactly how they will approach it. They will pull the belt and see if it still makes noise. If it doesn't, they will put the belt back on and use a stethoscope to localize which accessory is making the racket.

 

ok i will try that.....i learn something new everyday!!

 

Be very careful if you use a stethoscope - you don't want to get caught up in the fan or the belt. You can use a length of heater hose up to your ear for that.

 

Any tips for removing the crankshaft pulley?

 

Why do you need to do that? The only thing you have to do to remove the belt is move the tensioner pulley.

 

Mine was the AC clutch. It would squeal when I first started the truck and go away. Then it would squeal at the stop signs and lights. Became very loud. Replaced the AC clutch and haven't heard a noise from it since. Had about 150k miles on it. Good luck.

 

it could be my ac clutch. sometimes it will squeal for hours and sometimes it will be fine for hours. when it is squealing, and i turn the ac on to activate the ac compressor, the squeal gets a little louder.

is the ac compressor clutch difficult to replace?

 

Sounds the same as mine. I bought the AC clutch at O'Reillys. I had a problem wiggling the old clutch off the motor and then hammering the new one on keeping it straight to get it to slide on. The insturctions were for two types of clutches and it took me awhile to figure that out.

 

You can't prove it's the A/C without a stethoscope or similar device. Have you pulled the belt yet?

 

pulling the belt this afternoon.....will let you know how it goes!