A/C Compressor or tensioner?

chevrolet
suburban

#1

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??


#2

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?


#3

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.