AC compressor howl

[88lance]

2002 Tahoe, 233k miles. Had it about a year and half, and late last summer the AC started making a howl noise. Kind of a whiirrrr noise It sounds almost like a supercharger, but also sounds like it is vibrating, although you can't feel any vibration though.

I ignored it for awhile since it was getting to be winter, but now that im using it again, it started getting a lot worse, and a lot louder.

Took it to a shop and they replaced it with a GM compressor, a few other parts (I don't remember what else), vacuumed everything out, cleaned the system, and reinstalled everything.

2 days later, this new compressor starts the exact same howl.

Took it back and they said "bad compressor, replace under warranty".

So that's good, but I just think it's kind of odd that it is making the exact same noise....

They checked tensioner pulleys, (which I was assuming wasn't it since it only does it in the AC kicks on), replaced belts, ect.

I'm assuming there's no way this is normal, but I'm also kind of confused that both compressors would make the exact same noise...

Thoughts?

 

[Joseph Garcia]

If this were an old A/C compressor, I say this: Sounds to me like the A/C compressor bearing is going. To confirm, remove the belt, start the truck briefly and the sound should go away. Also, it could be the A/C compressor clutch is going, but I 'think' that the clutch is an integral part of the compressor, and cannot be replaced separately.

But, since you have replaced the compressor twice, it seems unlikely that it is the compressor that is the issue

You said that you 'checked' the tensioner. If you did not replace it, try replacing it, as the spring strength deteriorates over time through use and the continuous heat in the engine bay.

 

[88lance]

The AC compressor has only been replaced once, it was the original that was on it. We replaced it with the new GM one, and it's the one that started making noise two days later.

The tensioner didn't have any Play in it, but I'll go ahead and tell them they might look at replacing it anyway.

The only things I could think of is if the new compressor doesn't come with the clutch or something and they reuse the old clutch on them? Or something with the tensioner pulley somehow making noise only when the compressor kicks on.

 

[tom3]

Check mounting brackets and braces real close at the engine block. Had a truck with a rear brace that went to a stud on the exhaust manifold and the stud was broke at the block. All looked good, nuts were tight, but the brace didn't do much, just enough to let the AC comp. vibrate and make noise. And sometimes an older stretched belt will do weird things like this.

 

[88lance]

Interesting, I'll have them check this out on Monday. Even though I'm not paying for it, it would be nice for it to be something simple instead of of them tearing the whole thing apart again