AC repair advice please.....

[Jolly Roger]

When I turn on my AC it robs me of power.
To be more specific, when the AC is on and Im driving there is a substantial power loss of about 15-20% when the AC clutch kicks in.
Its very annoying, pressing on the gas and it not responding the way it usually does when the AC is off.
I know some loss of power is normal while running the AC, but how much?

Added to this phenomenon is a high pitch ringing noise that sounds like its coming from the compressor.
It comes and goes when the AC is on and it only lasts about 1 second each time it happens and occurs about once per minute. It sounds like a wet finger on a wine glass when it happens.
This noise has never been present when just the blower motor is on or with heat, so I dont believe its the blower motor going out.

The AC is works satisfactorily, but does its best at higher RPM. Just sitting still results in little to no cold air.
While Idling I can hear the AC clutch kick on and off and there seems to be little effect on the engine.
Its only while driving that the engine seems to feel like its pulling a camper when the AC clutch engages.

My Tahoe does have the rear aux AC option if that matters.
Thinking about just having the the whole compressor replaced. Its acted this way from the day I bought it at 34k and now its at 75k.
Should I have the compressor replaced?


....this is what it sounds like for one second at least once per minute....

 

[iamdub]

It really does sound like the compressor isn't turning as easily as it should. I've always felt the drop in power when the compressor is running, but it's nothing I'd describe as drastic as yours. Usually, this meant that the compressor was very near locking up, not lasting 41K miles longer.

 

[GreyStone]

Jolly..arent you in Alaska! ~ Roll the window down.

 

[swathdiver]

When I turn on my AC it robs me of power.
To be more specific, when the AC is on and Im driving there is a substantial power loss of about 15-20% when the AC clutch kicks in.
Its very annoying, pressing on the gas and it not responding the way it usually does when the AC is off.
I know some loss of power is normal while running the AC, but how much?

Added to this phenomenon is a high pitch ringing noise that sounds like its coming from the compressor.
It comes and goes when the AC is on and it only lasts about 1 second each time it happens and occurs about once per minute. It sounds like a wet finger on a wine glass when it happens.
This noise has never been present when just the blower motor is on or with heat, so I dont believe its the blower motor going out.

The AC is works satisfactorily, but does its best at higher RPM. Just sitting still results in little to no cold air.
While Idling I can hear the AC clutch kick on and off and there seems to be little effect on the engine.
Its only while driving that the engine seems to feel like its pulling a camper when the AC clutch engages.

My Tahoe does have the rear aux AC option if that matters.
Thinking about just having the the whole compressor replaced. Its acted this way from the day I bought it at 34k and now its at 75k.
Should I have the compressor replaced?


....this is what it sounds like for one second at least once per minute....

Compressor might be wore out or there's a problem with the clutch which is replaceable. Use your scan tool to see engine load at idle and at speed with the compressor and on and compare. The old GM R4 Compressors cost about 6 horsepower to turn, not sure what these take but they are bigger and more efficient.

Scan tool also shows torque so I reckon one could take a torque reading with the compressor on and off and do the math to figure horsepower. Who wants to be first? My brain hurts!

 

[79jasper]

You can also spin the compressor by hand. Maybe see if it feels like it is hanging up.

Sent from my SM-N960U using Tapatalk

 

[Jolly Roger]

Im in a bad predicament. I have no garage and I have to put my faith in a shop near by. I told them everything I've stated here and "they" say "All I heard was windshield noise". end of story.

I say "they" because the desk ladies are separated from the garage and mechanics. The ladies just reiterate or pass along what they were told to say. If I have any follow up questions all I get is a shrug.
I guess this situation works out fine to the people who just drop there car off and say figure it out and Ill write a check, but for people like me who want to know any details,..Im kinda the PITA customer or so I felt. This shop is BUSY! Maybe its just best to ask them to replace the compressor and be done with it.

After thinking about it a bit more the sound seems like its reverberating. Do you guys think that the AC pulley could be the culprit? It is bell shaped...kinda.

I just want my damn truck back sooner than later. This scheduling to have a look and then rescheduling a week later to do the work that may not fix the problem so lets reschedule again for the next guess is going to get old real fast. My truck is stripped of personal belongings for the time its being worked on. I keep survival gear and tools in the truck. The last place I took it to decided to help themselves to my survival food, stole my flashlights, ferrocerium fire starting rods and ripped off some of the velcro patches I had stuck to my headliner and switched out my gas cap for someones old one....because I guess they thought they deserved them?

Thank you for the replies gentlemen.
I figured Id throw my problem out there just in case one of you new exactly what it was. Im leaning towards replacing the compressor and pulley.

 

[CaptainAmerica1]

Put some gauges on it and check your pressures...

 

[bill1013]

Check to see that the serpentine belt is tracking correctly and not worn or loose. My 1999 Tahoe LT 4X4 had a similar problem and the belt was shot and the main pulley was bent way out of shape. Why? I have no idea. It was bent as such that the belt was shredded. Could never figure that one out...No damage to the front end, nor the radiator and no fresh markings or dings. And the AC was really cold...And my Tahoe had the compressor for the rear AC too. What a set up. Wish my Yukon had that.