Air Con Clutch cutting in and out

[Guest]

Just had my air con gas topped up and now the clutch on the compressor keeps cutting in and out at about 2 second intervals.
The engineer reckons it's either the temp or pressure sensor. Does anybody know how easy these are to replace and estimated cost for garage and DIY?

Cheers

 

[Stewart Rix]

Andy
I've got a similar thing. I had a re-gas a couple of weeks ago because it seemed my compressor was working too hard ie. cutting in and out frequently. Well, there was air in the system (no leeks fortunately) so the re-gas took the pressure in the system down to the normal levels. There was however no change in the compressor operation. The guy who did the re-gas thought it most likely to be a failed 'diff' - described as the electronic component that determines the range at which the temperature can vary before the compressor cuts in again. Instead of allowing a relatively large temp change (presumably in the element that chills the air), he thought it defaults to something like 0.5 'C; hence the regular cutting in and out. However, he wasn't familiar enough with 993's to say where and how it could be checked.

 

[Taverner]

Likewise I have had my A/C recharged recently. However the compressor has always cut in and out, when the engine is idling. It does the same on my BMW, so I suspect it is not a fault, but rather the standard way of operating. Perhaps to protect the compressor. When driving it is of course not possible to tell if it cuts in or out, because you cannot hear anything. My guy said that it was perfectly normal for the compressor to operate in this way. Maybe get someone to hold the revs up a bit say 1500/2000 and see what happens then.

You have got me thinking now, I must try this myself to satify my curiosity.

Michael

 

[Robert Greaves]

Just had my aircon checked and regassed and guess what - mine does exactly the same - perfectly normal its just the magnetic clutch cutting in and out. Apparently all air con systems do it - they are not continuously on as you would think - so breath a sigh of relief - why is it that we all get a bit paranoid when things like this happen.

 

[Guest]

Thanks for the replies folks, but I think it's been overgassed. When driving along you can "feel" it still cutting in and out; it cuts in with a hell of a jerk and makes the whole car lurch slightly!! Couple of seconds later cuts out again. I'm going to get the guy to bleed some gas out and see what happens.

Cheers