AC tensioner pulley rattles on 2001 GMC Yukon XL 1500

The noise occurs off and on when the air is on, it is a very loud rattling that makes you thing something is falling apart.I put on a new trnsioner pulley and no change, put on a different used working compressor no change. The air always works and blows cold air. The surpintine belt is new because it breaks belts at times. I got through the summer and now it will do it with the defrost on.

by in Chambers, NE on November 04, 2010
2 answers 4 comments
ANSWER by on November 04, 2010
I have seen this problem on some 2002-2003 GMC Yukons, so this may or may not apply to your vehicle. What I have seen is the load of the compressor causing the belt and tensioner to jump, hitting the transmission cooler lines causing a rattling noise. There is a service bulletin from GM for this issue #03-01-38-019A. But again, it does not specifically apply to the 2001 model year. The repair is to replace the compressor with an updated unit and install an inline filter. If you can verify you have the exact symptoms as I have described you may still have an issue with your compressor. Perhaps discussing this issue with your local GM parts supplier would be a good idea. They may be of help in determining it the 2001 and 2002 compressors are the same, if so perhaps you could try the updated compressor in your Yukon.
COMMENT by on November 05, 2010
I do not think this applies to the 2001 Yukon because the compressor is on top no where close to the cooling lines. The tensioner pulley is not rattling against anything it just vibrates back and forth.
COMMENT by on November 09, 2010
The A/C could be building to much pressure causing the compressor to over work, putting extra strain on the belt and tensioner. If the problem never occurs with the A/C compressor off then you would think the fault is with the a/c system. Checking a/c pressures while the problem is occurring should probably be the next step.
COMMENT by on November 15, 2010
This has happened with two different compressors. Is there something other than the compressor itself that regulates the pressure, or do I have two compressors doing the same thing?
COMMENT by on November 15, 2010
The pressure cycling switch on the accumulator cycles the compressor on the low pressure side and there is a high pressure switch to turn the compressor off at extreme high pressure. I don't think one of those would be at fault. Perhaps there is a restriction or a cooling fan/condenser fault that is causing abnormally high pressure but not high enough for the high pressure switch to activate.
ANSWER by on August 14, 2011
Hello friend, I have the very same rattle and now i am concerned as to what to do. what was the ultimate fix for your situation.
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