New AC compressor making noise

[gmdrvr]

I rebuilt my AC system with a new compressor, new main line, new condenser, new O/T and new accumulator. I flushed the evaporator and left the rear ac alone. After I put it all together I vacuum tested the system and let it sit with a vacuum for an hour and it held. I put the recommended oil and refrigerant in, the low and high pressures are correct and the AC is blowing at 39 degrees.

When I went to take the truck for a drive there was a fast clicking noise at idle under the glove box in the evaporator area.The noise would stop when the compressor turned off. The clicking sounds like the pistons in the compressor and it goes to a higher pitch while accelerating, makes a buzz noise (like a transmission stuck in low gear) then it just stops making noise when the compressor turns off. Under the hood I don't hear it, only inside the vehicle with the doors shut.

Any ideas? Is it a bad compressor or is there like a break in period?

 

[SunlitComet]

is it possibly the recirc motor?

 

[gmdrvr]

No because the noise quits every time the compressor stops, even with the blower still on.
The noise also changes pitch with the engine RPMs.

 

[SunlitComet]

does your line on top rear of compressor have the muffler on it?

 

[gmdrvr]

Yes the low side coming to the compressor has a muffler and the high side leaving the compressor also has one.

 

[SunlitComet]

hmm, possibly overcharged making the compressor struggle then. have you done a performance test on it yet?

 

[gmdrvr]

have you done a performance test on it yet?

The performance test checks out, I have 42 on the low side and 200 on the high side and 39 degrees at the vent.
Do you think the noise could have something to do with the accumulator? I asked for all the parts that go with a Yukon with rear AC but the accum. was a little shorter and more tapered at the bottom than the original one. Would an accum. for a non rear AC system even fit on rear AC system?

 

[SunlitComet]

the accumulators are different. did you put the wrong one in?

 

[SunlitComet]

can you get an audio recording of the sound please?

 

[gmdrvr]

The part number for the accumulator is Everco 4539N and/or 33219. I asked twice to make sure it was for systems with rear AC and he said yes, but who knows.

I will try and get a recording of it if that IS the right accumulator.



Edit: I found the sound already posted on youtube, it is from a Mini, apparently a good number of Minis have this problem

 

[gmdrvr]

The guy in video turns the AC on at 14 seconds so that's when the noise starts. After looking more into it I found Mini had a TSB on the issue and the fix was putting a weighted damper on the suction line behind the compressor. That is something I shouldn't have to do since GM did not have this problem in their design.

 

[SunlitComet]

i cant make anything out except what sounds like road noise and kinda like wind noise.

 

[SunlitComet]

any chance you got a line banging against something?

 

[gmdrvr]

i cant make anything out except what sounds like road noise and kinda like wind noise.

Did you see the post I added to the video? It went to page two.

The guy in video turns the AC on at 14 seconds so that's when the noise starts. After looking more into it I found Mini had a TSB on the issue and the fix was putting a weighted damper on the suction line behind the compressor. That is something I shouldn't have to do since GM did not have this problem in their design.

Here is another video where they show it with the AC on and with it off

This one starts at 13 seconds, very distinctive high frequency pulsating noise that sounds like a gear box with one gear. It gets quieter when the RPMs drop like when the vehicle shifts.

 

[SunlitComet]

sorry man, i am just not hearing it thru my end. regardless that is not yours so i would presume their fix would work for you.