Automotive Air Conditioning Information Forum (Archives)

idickers on Thu July 31, 2014 10:55 AM

Year: 2009
Make: Mini
Model: Clubman S
Engine Size: 1.6 L
Refrigerant Type: 134a
Country of Origin: United States

How can I determine when an a/c compressor needs to be replaced? The compressor on my wife's 2009 Mini Clubman is groaning when the a/c is engaged. The noise getting louder with time, and is louder on acceleration, and will immediately go away when you turn off the a/c while driving. It is a little weak on cooling, but it seems to be still functioning. The groaning noise makes me think it's a bearing, but I don't know what is serviceable on this compressor. The replacement compressor is $600 alone, so I'd like to keep running this as long as possible, but I don't want it to grenade and spit metal into the rest of the system.

HECAT on Thu July 31, 2014 1:16 PM

Sometimes the groaning comes from an external source such as the belt, belt tensioner, compressor clutch, clutch bearing, etc.; all of which will also quieten down when disengaging and removing the compressor load. You can use a stethoscope or a long rod (one end to your ear) and carefully probe while the groaning is occurring to isolate the root cause of the noise. You can get some gauges on it an see if the noise corresponds to some needle jumping, this can also be a way to confirm its internal. Marginal cooling indicates something is amiss, a low charge (leak) will slow the return of lubricating oil to the compressor. According to one reputable source that frequents here; low charge is a symptom/cause of 65% of compressor failures. If it is compressor internal, then an audible noise usually indicates the metal grinding and some system contamination may already be occurring. HTH

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