New AC Compressor Noise

[99Tahoecar]

1999 Tahoe - Replaced the AC Compressor which (per instructions) required 2oz of compressor oil. Within an hour, the compressor began making an unusual noise that increased in frequency with higher engine rpm's.

Hard to describe the noise, but similar to the flapping sound a playing card makes when struck by the spokes of a spinning bicycle wheel. Anyone else experience a similar noise? Any thoughts on the source of the noise? Too much/too little compressor oil?

 

[WalterMitty]

1999 Tahoe - Replaced the AC Compressor which (per instructions) required 2oz of compressor oil. Within an hour, the compressor began making an unusual noise that increased in frequency with higher engine rpm's.

Hard to describe the noise, but similar to the flapping sound a playing card makes when struck by the spokes of a spinning bicycle wheel. Anyone else experience a similar noise? Any thoughts on the source of the noise? Too much/too little compressor oil?

I had a new compressor installed in my 96. It is definitely noisier than the old leaky unit but has worked well for several months now.

 

[Tahoecar]

Thanks Ken - good knowing I'm not alone. I took my Tahoe to a knowledgeable old timer (former auto shop owner and auto enthusiast) and asked him to listen to the compressor. He said that some new compressors are more noisy than others. However, mine sounded like there was either a) too much pressure on the compressor head - possible obstruction in the AC system - or b) something that had found it's way into the compressor itself. Note: The noise, coming from within the compressor, sounds more like a rapid clicking.

He said that I should ensure that the system has an adequate freon charge and then, using gauges, re-check line pressures. If the low-side pressure is at the low end of the acceptable range (when compared to a pressure table) and the high-side pressure is at the upper end of the acceptable range, it's possible that there is an obstruction in the system. I checked, and that is the case.

Guess I will plan a date to evacuate the freon, vacuum the system, open it and methodically check each component for obstructions...

 

[AtomicHoe094]

Yikes, well that sucks. Did you replace the orifice tube?

 

[Tahoecar]

Spot on question...embarrassed to say that I did not. The orifice will be the first place I go to look for debris. Also, after draining the oil, I plan to run some compressed air through the compressor ports. Thanks Adam.

 

[AtomicHoe094]

No problem. Hopefully you can catch the problem before it really messes with the new compressor. Ive heard to also replace the accumulator? i think it was when you do any AC parts swapping. Ill have to verify that, but it just helps and ensures the swap will go smoooothly

 

[Tahoecar]

Good advice - thanks again.