A/C Compressor Whine - Advice requested

[Rawhide]

Hi, my 2007 Edition 30 is making a whining noise which stops immediately when I switch off the A/C.  It's related to engine revs and quite noisy in the cabin.  I have a hunch it's got a bit louder over the last few weeks.   When I got the car it had an A/C fault. 


00229 - Refrigerant Pressure
            002 - Lower Limit Exceeded - Intermittent

I topped it up using a home kit and re-scanned and it went.  It was not expected to last a long time. I don't have any errors now but the temperature is not that low and I'm thinking I might be smelling some refrigerant but I could be imagining it.

I'm reading the compressor is a weak point on these cars.  I'd like to tackle this job myself but would like to know if there is anything to try before before replacing the compressor.  I will visit quik fit to have them test the system and drain the refrigerant first so it doesn't discharge into the environment.

Can pattern parts be ordered or does it need to be a VAG stamped part?

[pudding]

Sounds like you have a refrigerant leak and a test is good idea because the AC pump is the most expensive part, so you don't want to change that unless you have to.  The condenser is common leak point as it gets battered with stones and winter salt.  Rought £100 for the part from Eurocarparts (double from VW) and easy to replace DIY.  You just need to take it for a gas recharge afterwards....and environmentally speaking, you're supposed to get a discharge before working on the AC system, but not many DIYers do that.  Just don't breathe the gas in!!

AC is a pain in the neck and I often toy with idea of deleting it, but no one would buy a car with deleted AC, so you have to stomach the bills......for the occasional hot day we get!

[Rawhide]

Thanks Pudding.  Thats why Kwikfit are quite handy as they will drain the systems of gas, then vacuum test it which has the effect of drying out the moisture in the system.   If there is a leak then they won't charge for that as they were not able to actually gas the car.  It's also eco friendly as the system will no longer have refrigerant in it.

I'm reading that some compressors are better than others and Sanden is the one to get which runs at around £280 ish.  I also see used pumps on ebay for £20 but I don't like repeating jobs on a car so will likely get a new one.  As far as I can tell either bumper off, or alternator off.   I'm thinking bumper off would be easier with the car up on ramps.

My only concern is the pump might be good but there is a leak elsewhere but I really don't think it can be healthy given the whine it's making.  I'll ask kwik fit if they can put some dye in the system.   Contrary to popular opinion my local branch are really quite good. They removed my rear brake dust shield for me when it was dragging on the disk at no charge.  it took them about 1 hour also :)

[Shoduchi]

Check the gas pressure sensor. Mine was leaking through the electric connectors! I also had a faulty gas pressure regulator valve. The compressor itself was still in good enough condition. I replaced the compressor and only afterwards I found out were the leak was.

[pudding]

Thanks Pudding.  Thats why Kwikfit are quite handy as they will drain the systems of gas, then vacuum test it which has the effect of drying out the moisture in the system.   If there is a leak then they won't charge for that as they were not able to actually gas the car.  It's also eco friendly as the system will no longer have refrigerant in it.

I'm reading that some compressors are better than others and Sanden is the one to get which runs at around £280 ish.  I also see used pumps on ebay for £20 but I don't like repeating jobs on a car so will likely get a new one.  As far as I can tell either bumper off, or alternator off.   I'm thinking bumper off would be easier with the car up on ramps.

My only concern is the pump might be good but there is a leak elsewhere but I really don't think it can be healthy given the whine it's making.  I'll ask kwik fit if they can put some dye in the system.   Contrary to popular opinion my local branch are really quite good. They removed my rear brake dust shield for me when it was dragging on the disk at no charge.  it took them about 1 hour also :)

You can also see the AC pump if you take the lower half of the driver's side arch liner down 

If the leak is bad enough to nearly drain the system, I imagine the pump would get noisy!  Refrigerant contains oil for the pump too, so if that's all gone, it'll get noisy.  I hear they make more of a deathly rattle when knackered, rather than a whine. 

If you do replace the condenser, it's a good idea to replace the receiver / drier canister as well, which next to it.  Just in case the pump is starting to let go and spreading shrapnel around the AC system.

Yeah just like dealers, some Kwik Fits are pretty good!

Good luck, keep us posted!