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Hi All,

Have done a couple o searches but cant find anything similiar to my problem.

Basically no cold air from aircon.

System has been re-gasssed twice and pressure sensor changed, by Independent Audi specialist. No fault codes either.

I personnel think the compressor is broken, but before speding alot of money on a replacement, I wondered if anyone had similiar issues. Audi specalist I use said he has never seen a failed compressor on a B7 RS4, thats not to say its not the compressor.

A couple questions,

Does everyone see a blip in the revs when aircon is switched on? I have seen this on all other cars I have owned but as silly as it sounds just wanted to check.

When you switch from econ and other fucntions on the control panel you can hear the flaps etc behind the dash moving, so I think the control panel is ok.

Also not sure but does anyone else have issues with car steaming up, it dosent do this alot but due to the fact the aircon is not working it seams to be quite moist air in the cabin.

Also anyone recomend any compressor suppliers they have used for genuine Denso, as Audi are wanting serious money. Seen a couple from the states on E-bay etc.

Any advise greatly appreciated.

Thanks,

Dose the red light on the econ button ever go out?

Can't advise you on the air con but it may be worth asking if this guy has the compressor still available

viewtopic.php?f=35&t=114005

All my cars have always had a blip in the revs when the air con compressor comes on, same as when you turn the steering wheel slightly. I believe it drops due to the extra load then the engine speed adjusts to keep the revs in the right range.

Hi there.
My RS4 B7 was 70 kkms when the compressor went out.
I had to change it and many parts around.
It seems to be the previous owner who was not using Air-Con that much ...

Around 2000 euros to repair.

EDIT : if you go for a new compressor, choose the DENSO brand which is the OEM supplier ...

Lukes3, I am not sure will check thanks.

Thanks Adrian, but due to labour costs think I will go for a new part as dont want to risk having to do it again.

Yeah Mike, thats what I though, I have had it on Vag Com and watched injection timing and engine load IIRC and never seen it change.

Looks like buy a new compressor and see what happens.

The AC on my B7 failed over Xmas when we were doing a 5000km trip through the middle of Australia - some days 40deg

It would work for about 20min then slowly fade

The evaporator was freezing as the orifice was blocked and as it froze the air couldn't get through

Does yours have similar symptoms

Graze

If it's holding gas and you can't hear the revs drop then it's the compressor. The compressor is driven from a pull that has and electromagnetic clutch. In essence the pulley is driven all the time by the engine but the compressor internals on spin when the clutch is engages. Its this that causes the revs to dip. No dip, then most likely no engagement. It could still be an electrical issue though I suppose.

HI Graze, no might just doesnt work at all.

Thanks RS6BRIT, yeah that was my thinking, I agree with exactly what you said.

Has anyone had any dealing with overhauled compressors from these guys.http://www.compressor-express.com/about-us

Thanks again all.

Hi All,

Just an update for this post.

I purcahsed a genuine Denso compressor from Compressor express as listed above, they didnt have one in stock, and it came direct from Novo parts in Budapest, so not sure if you could source one direct from them, I had a look online, but there website is in Hungarian with no English option I could see.

Anyway, pretty good service from Compressor express, TNT delayed delivery a day or so as they sent it to the wrong place, anyway, looked genuine Denso part.

Audi specialist I used fitted it, this turned out to be alot more work than expected, I was quoted 10 hours, billed for 12, but he said it actually took longer.

Air con is now working, so all good, just very expoensive cold air!! ha ha

Out of curiosity (as my system has a slow leak from the compressor ) what was the total cost mate ?

Hi RS6 Brit,

Total cost was +/- £1500. This included oil and filter change, gaskets, consumables etc.

i have a issue with my air con the econ light wont go out any ideas possible top up?

Regy53 wrote:i have a issue with my air con the econ light wont go out any ideas possible top up?

I thought the Econ light was just to indicate the Econ was on, and when the lights out its in the off mode?

If the light is staying on I cant remember exaxtly the reason, its on here somewhere if you have a search.