Problem with AC on full size Chevy truck, need thoughts..?

[Samckitt]

It is a 2003 Chevy Silverado with about 135k miles. In the past 2 or 3 months I have broken 2 belts on the AC compressor. When belt is good, AC is running, & setting at a stop, it idles rough. Turn the AC off & it runs smooth. So do you think I have a problem with the AC compressor?

[Iamtheonlyreal1]

Check the Belt tensioner for the AC... When I worked for G.M. we changed many of them, because the tab that keeps the limits on it would break off... Also, make sure you Condensor is cleaned out, just run a couple of dollar through the Condensor at the car wash.. Sometimes the head pressure would get too high due and cause too much strain on the compressor and tensioner, and cause the belt to break or get throwne off.. It is a very small and weak belt, so it doesnt take to much to lose it..

[Samckitt]

I did notice this time when I got under it, that the tensioner wheel/pulley is actually touching the pulley on the compressor.

[wedgehead]

We have done many of these here at my shop. GM even has a bulliten on this. The fix is replace the compressor. The tensioner is not the problem.

[Samckitt]

We have done many of these here at my shop. GM even has a bulliten on this. The fix is replace the compressor. The tensioner is not the problem.

FART! How much is that gonna cost? Got a bulletin number?

[406 Q-ship]

Before you change the compressor, check the bearing on the A/C compressor clutch they can start to fail causing the rough idle or even stall the engine.

[Samckitt]

I found a GM TSB online stating that it has the exact symptoms mine has/had. It sounds like it is the bearings that has gone bad. So can that be fixed without unhooking the AC lines? So I don't have to vacuum & recharge it.

[Rhino]

It can be fixed without unhooking the lines, but don't think I'd want to do it. The clutch will have to be pulled to replace the bearings. Doing that with the compressor in the truck won't be fun, assuming it's down low on the passenger side of the motor like my Avalanche.
Is your truck 2 or 4wd? If it's 2wd it may be more accessible from the bottom side.

before you go through that trouble, make sure the system isn't overcharged. With an overcharge, you can suck liquid into the compressor causing it to shutter. This shuttering will wreak havoc on the tensioner and cause symptoms you're experiencing.

[Iamtheonlyreal1]

The head pressure caused by a restricted AC condensor will also cause the shutter and damage the tensioner.. I dont know how many vehicles that came in the shop only need the condensor fins cleaned out, and it took care of the problem. You may have to go ahead and change the Tensioner, due to damage, but it is very easy to determine.. If you have changed your AC belt, you know it is a very weak setup and doesnt take much to manipulate or damage it.

If you have never cleaned out your condensor fins or between the condensor and radiator, I would give it a try. You dont have to remove the Radiator, just lay it back and run a pressure washer through the condensor with bending the fins..

Depending on where you live, you may find a bunch of debris in the fins and between the radiator.. I live in southern Oklahoma, and we find cotton wood, straw and grass, BUGGGGGS (bug guts and bodies will totally block the condensor), ect, ect..

[Samckitt]

It is 4wd, I will try spraying out the fins now & get a new belt & see what happens.