AC compressor locked on NEW system

[newworker18]

Hi everyone,

 

About a week ago I was driving with the defrost on and horrible loud vibration sounds were coming intermittently from my engine. I was able to make it home when VERY loud squealing occurred and I parked and turned the engine off. I started it up again and switched off of defrost and the sound went away, then I tried it with AC/defrost/all the options combining those two and knew something was up with my AC compressor system...again!

 

Looking at the unit, when the defrost or AC button is pushed, the clutch engages, then the cutch and pulley unit turn together for ~1/5 of a revolution and the unit locks up causing the squealing noise and burning serpentine belt horribleness. 

 

My question is...the entire system got changed 3 years ago so it is basically brand new. There should be no reason why it's not working again, and when I got it replaced it was with a mechanic I had known for a while and trusted.

Could it maybe be an electrical fault somewhere and a signal isn't getting through? I just have a hard time believing it's the hardware and I do not want to go to a mechanic and have them tell me "yeah it needs to be replaced" or they better have a really good reason!

 

Thanks for any help, it has been bugging me :]

 

- Chris 

[Jsdirt]

I don't have any good news for you, Chris, unfortunately ...

 

Compressors only lock for a few reasons - mechanical failure, lack of lubrication, or too much oil.

 

What I suspect MAY have happened is that you had a Low Pressure Cutoff (LPCO) switch failure, which caused the  refrigerant pressure on the low side to become so low (below freezing in temperature) that the oil turned to molasses, and starved the compressor of lubrication. Another possibility is the chinese parts every mechanic and DIY'er has been dealing with the past several years - your compressor may have just failed due to crappy manufacturing and/or poor quality parts.

 

What sucks about this is, a compressor failure means a new compressor, new condenser, new orifice tube, AND a new accumulator - all of the shrapnel from the failed compressor lodges in these components and cannot be flushed. You could probably clean an orifice tube, but at $2 for most of them, just replace it. You'll also have to flush the evaporator. Basically,  you're starting all over again. 

 

Might get lucky and have caught it before alot of trash got sent through the system - only one way to find that out.

[txab]

 Would suggest replacement of the condenser if the system grenaded. Condensers cannot, generally be flush effectively and remove all debris

[Jsdirt]

You CAN flush an evaporator - not a condenser. 

[newworker18]

Okay, at least I can mention that to the mechanic when I bring it in :].

 

Yeah, I read about all the metal pieces that go through...but I don't have the tools to properly flush/vacuum the system, plus I'd need that special tool to remove the compressor since GM has to be special! 

I was mainly curious what could be the cause since it's so new.

 

Are there ways to easily check the oil & lube in that system? I feel that is something that should stay consistent since that isn't a task that gets routinely checked, but I wouldn't mind doing it to catch any bad thing before it happens. There is no way I am getting it changed a third time haha.

 

Thanks again,

 

- Chris

[carnau]

Is the system low in Freon? A lot of times the sytem gets low in Freon and the compressor locks up. The new trucks are known for having condenser leaks. If the condenser is leaking and causes the system to run low in freon  it could definitely cause the compressor to lock up. 

 

I called GM tech assist about this problem a while back because it seemed to be a common problem and that's one of the things they explained to me.

 

But with that being said. These parts are man made and nothing is perfect. 

[newworker18]

I read up on that, but I assumed it was already past the point of no return.

Maybe I will check it; I have done that before and it's straight forward. 

The only problem is the AC has to be on for a few minutes (correct?) and I feel like the belt might...break...if the AC is on for longer than a minute at most.

[txab]

2 hours ago, Jsdirt said:

You CAN flush an evaporator - not a condenser. 

Yeah, I was trying to get the answer out in a hurry and interchanged the two...... Correct the condenser will nee to be replaced. I'll correct my earlier post

[txab]

1 hour ago, newworker18 said:

I read up on that, but I assumed it was already past the point of no return.

Maybe I will check it; I have done that before and it's straight forward. 

The only problem is the AC has to be on for a few minutes (correct?) and I feel like the belt might...break...if the AC is on for longer than a minute at most.

Your compressor is shot, no doubt