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A/C Compressor or tensioner?

I have a 2000 Chevy Suburban. 229k well maintained. I had her (Buttercup) recently tuned up and drove on a trip of 1000mi. I started noticing a “rattle” in the range of 17-1900rpm after 500miles. The “rattle” sounded like a rivet gun being held against the engine block at the specified rpm. Additionally, the motor runs slightly rough at idle rpm all systems running. If I unload the a/c the motor runs smoothly @650-700rpm. The mtc rep said the compressor is failing and I should replace it immediately to the tune of $1500.



There’s one check they didn’t do and that was to check the tensioner to see if it had failed. The way I see i, if the compressor is failing, I would see it throughout the rpm spectrum…I don’t. Further, the a/c runs normally thoughout, even through the “rattling” phase.



What’s the probablity of the tensioner failing and the compressor is ok? I haven’t replaced the tensioner since I have owned her.



So, Whaddya think??

What you describe is exactly what I experienced a year or two ago in a 2000 model year GM vehicle…right before the tensioner pulley went kablooey.

Replacing a tensioner is an easy thing and not very expensive. At this age & mileage it doesn’t make much sense to not have it replaced - even if you find out it isn’t the source of the noise.

What is an mtc rep?

Mtc rep is short for maintenance Rep. Sorry for the shorthand.

Thanks for the advice. I think I’ll replace the tensioner and the belt befor I go any further.