Hi all, hoping someone can help me out here.
I have a 2000 GMC Sierra 1500 with the 5.3 V8 with about 135Kmiles on it. Occasionally I have heard a high pitch screech coming from under the hood, it lasts only a second or two and is very random.
Recently the screech has become much more frequent, even predictable, mostly under acceleration, and occurs every 15 to 20 seconds at highway speeds, and the duration of the screech is sometimes as long as 5 seconds now..
All I have determined at this point is that when the screech starts, if I immediately turn off the air conditioner with the button on the HVAC panel, the screech immediately stops.
This leads me to believe it is either a belt issue or my compressor is going to go out on me.

Anyone have any experience with this?

Thanks in advance.

 

Check the belt going to your AC, then start looking at AC clutches.

 

thanks for the tip Smoke.

The belt is definately intact, doesn't look too worn although I am sure it is the original equipment belt.

Is the clutch repariable without removing the compressor?

Does the fact that it is pretty much occuring at almost exactly 15 to 20 second intervals suggest the compressor trying to engage but a faulty clutch screeching?

Odd thing is that the air seems to be working fine, plenty cold, keeps up just fone on a hot day.

Thanks again.

 

Sounds like a slipping belt to me. I would start there before going after the compressor. The tensioner may be going bad that holds the serpentine belt together. However you mention that the belt looks bad. If it cracked up at all replace the belt. Belt is usually decently cheep. I am no expert but I beleive that you will have to replace the entire compressor if this is what is bad. If you are going to replace the compressor yourself you will want to have the system evacuated by a local shop first.

 

Yes,usually its the tensioner that comes apart...but that screech sounds like the clutch slipping before she engages...does the end look yellow/burnt?

And yes,it would take an entire compressor

 

it does sound like the compressor is wearing out..... just not done yet.

 

Thanks all.
The serpentine belt and tensioner is fairly new, I replaced them myself probably 18 months ago.
From what the manual says, on the V8 models the compressor is down low on the RH side of the engine and is NOT on the serpentine belt but is on a secondary V belt and as I said earlier, that belt looks fine.

I have done some checking and it appears as thoughtthe clutch mechanism is available separately as a part so would that indicate I could possibly change just the clutch and if so could I do it on the truck or do I have to evacuate the entire system and remove the compressor???

Thanks again to all.

 

Well if the ac belt is factory then i would say replace it anyways and see what happens. From what i have seen is the ac belt really only last 5 years or so. Not sure what others guys have seen but i have been around 3 2000s and they went bad at about 5 to 6 years. And they are not to much so i would replace it and then you will not have to worry about the belt for a few years. Thanks

 

Thanks, I am sure the cost of that belt and effort to install it cannot be to bad so I will give that a try first.

 

It sounds to me like it's the ac clutch!. Especially if you changed the tensioner and belt recently. You can try some spray lube as a temporary fix, if it quiets it down, you've found your problem.