A/C experts in the house? Belt chirp when A/C compressor engaging

[roc1967]

Hey guys... any advice or insight is greatly appreciated.

I have my '02 Tahoe for 10 years, it has 180k miles and it's in great condition except for body rust (Indiana!).

This issue started a couple years ago, but it was infrequent and very random at the beginning, a noticeable belt chirp when the A/C compressor was engaging, only happening in hot weather or when the engine was hot soaked, then following A/C compressor engagements were quiet and eventless. Explaining better, when engaging the A/C compressor when the engine was cold (e.g.: in the morning), no belt chirp, but once driving for a while and park the car, once hot soaked, they would be a clear belt chirp, sometime quite long, so I'd actually turn A/C off.

It's getting warmer here (~70F today) and there was a noticeable belt chirp when engaging the A/C compressor while driving on the interstate today. The frequency of the chirp has been increasing.

Any lead on what might be causing this belt chirp? Could it mean that my A/C compressor is worn out and close to grenade?

 

[George B]

Check the belt and tensioner.

 

[Joseph Garcia]

Replace the belt and the tensioner together. RockAuto.com has them. It is about a 1/2 hour job. Easy peasy.

At your mileage, your tensioner has lost a good amount of its original spring strength.

 

[corvette744]

Check the belt and tensioner.

Very common for the tensioner to go bad especially in the salt area you live.Looking at the belt condition is a no brainer-but always change the tensioner when you change the ac belt.Start their take belt off spin tensioner and inspect belt good replace if any concern at all.Spin ac pulley make sure no grinding noises.

 

[roc1967]

Thanks a lot for the suggestions so far guys. Belt & tensioner are too easy and cheap to not do it, but I don't think that's the root cause. They're about 15k miles old, GM genuine parts.

Let me to elaborate:
It really feels like the A/C compressor is locking up or seizing when hot soaked, as if it was trying to compress liquid instead of gas. Here's how it happened at the first time, a couple of summers ago:
We drove to an air show a couple of hours away, ~90F day, parked there for a couple of hours. Then I started the engine fine and when I turn A/C on, there's a loud and long belt chirp, and lugging the engine down a couple hundreds RPM's, so I kept A/C off for the rest of the day, thinking that my A/C compressor was seized for life. So next morning I turn A/C on just to double check, and it worked normal, no belt chirp or lugging. Then later I realized this pattern that this is happening following hot soaks in hot days only.

But as time is passing, it's happening more frequently now, not requiring really hot soaks/days anymore.

 

[George B]

Thanks a lot for the suggestions so far guys. Belt & tensioner are too easy and cheap to not do it, but I don't think that's the root cause. They're about 15k miles old, GM genuine parts.

Let me to elaborate:
It really feels like the A/C compressor is locking up or seizing when hot soaked, as if it was trying to compress liquid instead of gas. Here's how it happened at the first time, a couple of summers ago:
We drove to an air show a couple of hours away, ~90F day, parked there for a couple of hours. Then I started the engine fine and when I turn A/C on, there's a loud and long belt chirp, and lugging the engine down a couple hundreds RPM's, so I kept A/C off for the rest of the day, thinking that my A/C compressor was seized for life. So next morning I turn A/C on just to double check, and it worked normal, no belt chirp or lugging. Then later I realized this pattern that this is happening following hot soaks in hot days only.

But as time is passing, it's happening more frequently now, not requiring really hot soaks/days anymore.

Ok, this was critical information. I have heard of compressors going bad and or an oil slug causing this.

 

[Scottydoggs]

i had a 03 gmc pick up that the belt never chirped, but it broke the belt 2 times, then broke the tensioner, so next step was the compressor. after that it was like new again.

 

[RAMurphy]

That was my issue several years ago. If it is the compressor which must likely it is you want to get that changed. It will only get worse. I lived with it until the compressor decided to frag itself. Any easy compressor (ok relatively easy) change became a major effort of changing numerous parts and flushing the entire system. What a PITA and very time consuming if you do it yourself (I did) or very very expensive.