I have a squealing engine noise in 01 GMC yukon?

[Jorge]

IT only squeals when A/C is on and im accelerating, it does NOT squeal when idle and A/C is on or when the A/C is off.or when crusing at any speeds and A/C is on it only squeals when A/C is on and im applying a little gas. What might be the problem is it the compressor?

 

[KalEl2]

I agree with JOHN aswell, although, you should consider this, if you truck has a timing chain, you won't need to place it, just tweak it a little. Any shop that tells you, you need to replace a timing chain, don't fall for that, timing chains are damn near indestructible

 

[JohnG]

I would think the belt or idler is shot. If the belts never been replaced, start there. these belts don't crack like they did on older cars, but they do stretch. When you engage the compressor, and the engine revs, torque forces the belt to form a dip. Really a pretty common problem.