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Discussion Starter · #1 ·
When I press down the AC button, I hear the compressor kicks in and the engine raises revs slightly.
BUT... a loud drilling noise shows up and it will gradually decrease to a whisper in a few seconds. After few minutes, the noise comes up again and diminishes by itself in a few seconds later.

I took the car to a specilized garage to re-gas the system a month ago. There were only 60 grams left. They checked for leakage and changed the pollen filter. Also, during the winter months, I power the AC on for a while regularly.

The AC cools very good, except for the noise that worries me :(

Where do you think the noise is originating? Have anyone experienced similar troubles?

I would appreciate any pointers!

Thx,
LZ0
 

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Could well be the compressor. There was enough gas in the system to start it - but once it runs for a few seconds the pressure on the suction side drops therefore cutting out the compressor on the low pressure switch. Once the gas settles - hence pressure rising across the system the pressure switch makes contact and starts the compressor again.
I had this problem on a Ford Ka yesterday.
 

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Mine does this too! Only it doesn't really die down so much really. It doesn't happen all the time - more when it's cold than when it's hot - again I don't seem to have any trouble with my AC other than that annoying noise!
 

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I take it the garage you took it too recovered what was in the system before refilling.

Do you know how much oil they put in? As too much is just as bad as not enough and will likely sieze the compressor.
 

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Discussion Starter · #7 ·
Well, I googled yesterday and learned more about automotive air conditioning. From the dry theory, I can conclude the compressor is causing troubles, since it's the only node, that holds rotating components (except the fan). Probably some bearing is worn...

Also checked under the hood. The belt is OK - not slipping or rubbing anywhere. The compressor mounting is tough.

What I'm gonna do next is remove the belt and try to rotate the compressor wheel by hand to see how smooth it moves. Will try to test the magnetic switch too.

Is it do-able to repair the compressor, if bearings are worn or it's sealed for life?
Is it possible to remove the outer pulley and grease the magnetic clutch bearing?

The device they use to re-gas, automatically doses the amount of oil, so the percentage of oil in the mixture must not be too much or too low.

http://www.familycar.com/ac1.htm
http://www.stealth316.com/2-ac-tips.htm
http://www.icarumba.com/icarumba/re...esourcecenter_encyclopedia_ac3.asp#inspection
 

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Discussion Starter · #8 ·
Could well be the compressor. There was enough gas in the system to start it - but once it runs for a few seconds the pressure on the suction side drops therefore cutting out the compressor on the low pressure switch. Once the gas settles - hence pressure rising across the system the pressure switch makes contact and starts the compressor again.
I had this problem on a Ford Ka yesterday.
How did you solve it? Will a system pressure test point mine has the same problem?
 
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