996 C2- Aircon Noise?

[ncollins]

My 996 C2 ('01 Facelift) has started making strange noises when the aircon is switched on! It sounds like an annoyed cat growling and is coming from the rear of the car when driving but difficult to hear if I stick my head in the engine compartment. The sound is intermittent so I'm thinking it's probably not coming from the aircon pump? The aircon still works efficiently but I've stopped using it until I can figure out what the noise is. Any suggestions before I take it to Autofarm for diagnostics?

Nic

[Henry-F]

I suspect it probably is the air-con pump. The pump cuts in and out as you use it. Topping up the refrigerent may cure the problem. Then you have to decide where the leak, if any, is.

If the front condensers haven't been done for a few years they would be my first port of call.

It could be the pump it's self is faulty but see what a bit more gas does first.

Good luck

Henry

[ncollins]

Ah, that's interesting, I seem to remember there was a comment at the last service about one of the front condensers being damp! I'll have to investigate further, thanks for your help.

Nic

[John Hatton]

my 2001 996 has the same groaning which cannot be heard at the engine so I think its not the comp.it is loud in the cabin but not from outside the car; its been doing it for about 10 years now, so can't be something about to break, but is very un-nerving. it goes up with the revs,but disappears at about 2000 rpm. I have had new rads, fixed the usual pinhole leak in the o/s pipe and had it recharged and checked again, but still the groaning carries on. so loud even my wife can hear it!
anybody found a real solution to it?

[AlasdairB10]

I had the same problem and thought it was the compressor clutch giving up. I took it in and Porschetorque found the system had twice the amount of gas in it that it should! That fixed it. Sounds like its your compressor though. Worth doing quickly (along with the dryer while you are there) as if it seizes it will put debris through your system and it will need a flush. The compressor is fairly common - Nissen and Denso both make them.

[LeighB]

AlasdairB10 said:

I had the same problem and thought it was the compressor clutch giving up. I took it in and Porschetorque found the system had twice the amount of gas in it that it should! That fixed it. Sounds like its your compressor though. Worth doing quickly (along with the dryer while you are there) as if it seizes it will put debris through your system and it will need a flush. The compressor is fairly common - Nissen and Denso both make them.

Mine's started groaning too but the system still blows nice cold air. It's not been re-gassed for the last 8 years when it had new condensers fitted so I'm suspecting the compressor is making the 'giving up the ghost' noises.

Are Denso (@£360) the ones to go for as D911 sells Behr/Hella OEM ones for £120 less?

And what is the dryer you refer to Alasdair?

[AlasdairB10]

One of these: https://www.buycarparts.co.uk/receiver-drier/porsc...

Quite cheap and worth doing while the compressor is out. It pulls water out of the system.

From what I understand, Denso is the OEM supplier for Porsche - which is why I'll get one when I need to replace mine. Nothing wrong with Nissen stuff at all though.

[996TT02]

LeighB said:

AlasdairB10 said:

I had the same problem and thought it was the compressor clutch giving up. I took it in and Porschetorque found the system had twice the amount of gas in it that it should! That fixed it. Sounds like its your compressor though. Worth doing quickly (along with the dryer while you are there) as if it seizes it will put debris through your system and it will need a flush. The compressor is fairly common - Nissen and Denso both make them.

Mine's started groaning too but the system still blows nice cold air. It's not been re-gassed for the last 8 years when it had new condensers fitted so I'm suspecting the compressor is making the 'giving up the ghost' noises.

Are Denso (@£360) the ones to go for as D911 sells Behr/Hella OEM ones for £120 less?

And what is the dryer you refer to Alasdair?

A compressor for £360 or less? Seriously impressed.

[rdodger]

I would suggest low gas and either leaking from the condensers or the AC pipe join behind the Drivers side sill.

[guywilko]

My C4 has a leak in the big front to back pipe. Any news if the OE pipe is back in production/ stock??
Cheers
G

[EGTE]

Have you asked an OPC?

[Slaav]

guywilko said:

My C4 has a leak in the big front to back pipe. Any news if the OE pipe is back in production/ stock??
Cheers
G

Northway still had it on back order a week ago....

[cvega]

had that issue , needed regassing (quite significantly). now all quiet again.