my truck is making this God awful screeching sound, coming from under the hood, its not the water pump as i just replaced it sunday. i believe its the A/C compressor. do they make this noise when the go bad? or does it just need to be recharged or what? would anything else belt driven related make this noise? lemme know

 

Check around the rear of the compressor. If it's wet, like oil wet, you may have a blown seal and the compressor is leaking PAG oil.

Could also be a bad compressor. One that has done it's time.


Try to narrow down and let us know. Does your A/C work fine?

 

Mine went and there was black oil splatered all over and of course it was making a terrible noise. I turned off the a/c (and the defrost) and the noise stopped for about a half hour and then it returned. The dealership told me that the whole thing, bearing and compressor would need to be changed. Right now I'm just by passing the AC pump because it is an expensive repair. My ram only had 110 000 km (60 000 miles) when that bearing went.

 

Another trick is to turn the A/C on and off, if the noise changes you can pretty much bet it is the compressor clutch, which means you need a new compressor.

 

Another thought is the belt tensioner. I had my water pump replaced, then started getting the screech when the AC kicked in. The shop that did the water pump said it (tensioner) looked okay, but the tensioner was the culprit. Did you get a new belt along with the water pump? That might be a good item to get, too.

When I got my tensioner off I could see it was rusted inside and also when I placed it next to the new part it was obviously not "springing up" as high/tight as it should.

--Lee