A/c Compresser

[chromedome]

Sometimes when I start the car and the a/c cuts in, I get a loud grating sound which I think comes from the compressor.

 

The compressor cuts in and out normally whilst the engine is running with no noise.

 

Any ideas?

 

Could in be the clutch mechanism?

 

Can you clean it and what with?

 

Thanks for any replies.

[seatkid]

eeek! Try and isolate the noise before doing anything drastic.

 

When you say loud grating, are you sure its not the "kettling" noise you get with low refridgerant pressure? It may also be the tensioner on its way out. Even belt slip.

 

If you really want to clean the compressor clutch, use spray brake cleaner, but allow to dry before starting the car. Don't be over zealous, avoid the belt and the compressor bearing end.

[chromedome]

The belt and tensioner have recently been replaced.

 

The a/c has just been fixed, leaking "o" rings on the compressor.

 

It's only been doing it since the a/c fix and I can feel the compressor kicking in and out when I drive the car, quite noticable. Never used to do it before.

 

Could it be that the a/c has been overfilled?

[seatkid]

Yes, its highly probable its been overfilled,leading to the clutch slipping briefly when starting the a/c. Total failue of the clutch is on the cards if you don't get this fixed. Don't use your a/c, take your car back and complain. Ask them for documentaion to prove the correct amount was put in, ask them to reweigh the gas and report the amount to you.

 

The amount needed is on a sticker under the bonnet, use the lower amount if you have the standard single a/c. The higher amount is for the optional dual a/c which is for cars that have cold air vents in the roof at the back of the car (rare) - NOT TO BE CONFUSED WITH DUAL TEMP CONTROL ON C/C which is standard.

[widget]

The aircon man said my 1.9 TDi had the dual system - how do you tell?

 

I'm now worried that:

 

a) he overfilled it - and thats why the compressor is not working, or

:ph34r: he charged me for regassing a dual system - when it was only a single.

 

 

also - with regards my compressor not engaging - should I try the brake cleaner around the compressor pully? (avoiding the belt and pulley itself)

 

....how do you clean the compressor clutch safely?

 

Graham

[chromedome]

Sounds like the two metal discs chattering.

 

I sat there tonight switching between auto and econ, for ages, and all I got was the normal click.

 

When the garage checked for leaks, the coolant apparently squirted out all around the compresser until they changed the "o" rings. So I'm wondering if the two discs have got contaminated with something which sometimes stops them working correctly.

 

I'll keep investigating. Thanks for the replies anyway.

[HJT]

The aircon man said my 1.9 TDi had the dual system - how do you tell?

Look at the headlining in the roof over the 2 rows of rear seats, if it has air vents, then it's the dual aircon, if no vents, then it's the single.

 

Howard