Overhauled A/C system, and now a noise
 

I have a 2000 suburban, 5.3 L motor, roughly 135,000 miles. I have an irritating noise coming from under the hood. I know it is the compressor or related to it. I can shut the switch off and the noise will go away. I turn it back on and the noise is back, I cycle it back and forth for a bit and after I drive for a bit it will eventually go away. I thought it was the new compressor, so I exchanged it for another one. It still does it. This is what I have done, new compressor and seals, new orifice tube(twice), new fan clutch. It holds pressure well and pressures run accurately with it cycling on and off. But it has a weird vibration noise at first start up until it has been run awhile. I am totally frustrated and ready to get rid of it after owning it since it was new. The only thing I have not done was change the accumulator, I probably should. My old compressor clutch quit working and the system was clean so I left the accumulator on. Any other ideas? Could it be too much freon in the system or not enough? I have at a loss of what to do next.

I have seen a bad serpentine belt cause noises. When the A/C is on there is more load on the belt and it could slip causing a noise. I bought a new serpentine belt from Autozone and it made noise until I replaced it. They sold me one too long!

Does the serpentine belt drive the A/C or is it a separate V-belt?

It will be a v belt for the compressor.

no it won't they're both serpentine belts but the a/c compressor has its own belt

i'd replace the ac belt and tensioner assembly if you haven't and are updating your a/c, the tensioners are known to have problems

as far as the noise without hearing it or knowing how exactly you did the jobs its hard to say, I would guess the belt/tensioner for starters

Either replace the v belt on the ac compressor or spray it with a belt dressing for starters.

If the AC belt is not new, it should be replaced as a place to start...
I believe there is a burnishing process for a new clutch if you did replace it..that process may need to be done also...

Tried burnishing
 

Belt and tensioner were both replaced, same time as compressor. I read up on the burnishing process. After I got home from work, I went to the garage and ran it through the process. Drove it around the block a couple times. No noise. I will drive it again tomorrow when it is cooled down again and see if it will make the noise. Thanks for all the help guys, I really appreciate the input.