AC noise, chirping then vibration when accelerating only

[wesmegan]

Started with chirping under hood near center of dash on a trip last Monday, only when AC is on and only when accelerating from a stop to about 30mph.

Then, day 2, add a vibrating noise to the chirping, which sounds like something is about to break, and stops if I let off acceleration or turn off AC.

HELP, my husband is outraged that the dealership wants to replace the AC compressor for $1500.

Still blows cold air and my clutch was replaced 50K miles ago. Already tried replacing AC Belt and AC tensioner - no change in noise.

What should I try now? 2001 Chevy Tahoe, 230K miles

 

[clkelley]

Welcome to the neighborhood!

It MAY be the AC compressor. But when you say you already replaced the ac tensioner, you mean the tensionor pulley? That is what it actually sounds like to me, if it were the compressor (and I am not saying it isn't really) I would tend to assume the ac would falter a little. I honestly have to give the same advice as in another thread, have your husband go purchase a stethoscope style probing tool. Then have him use that tool to "listen" to each of the pulleys and so forth on the front of the engine while it is running. BUT BE CAREFULL not to get into the fan while doing this. Using this method he should be able to better narrow down where the sound is coming from instead of guessing at it...

 

[wesmegan]

Yes, the ac tension pulley & belt were replaced today.

I assumed we had it narrowed down to the ac clutch or compressor, b/c the noise stops when ac is off, even if I leave the interior fan on the noise & vibration noise will stop.

Thanks for replying!

 

[clkelley]

I would definitely get other quotes on replacing the compressor. Although they aren't cheap, $1500 does seem excessive.

 

[markvdb]

It took 2400 to fix mine. If the chirping just started, DO NOT run the ac until it is fixed. Your compressor is slugging. Take it to a shop and have them check the inline filter. If there are no metal shavings in the filter, replace the compressor with a new Denso model. DO NOT use 4 seasons, I went through 3 of those. When the compressor is replaced, have them double check the oil level in the system. A small low oil condition can cause slugging. You can add oil if there is no shavings, but I would advise the new denso compressor, it is redesigned. IF there are metal shavings in the filter, the system will need flushed. I waited too long and had to replace the condensor, evaporators, everything. Do not wait, and do not run the ac until it is repaired.

 

[Onatebuawer]

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