AC Compressor Noise 2008 S80 D5
 

Hi Guys,

Last week I was foolish enough to loosen the plastic bung on the bottom of the AC condenser thinking it was the radiator. (I was replacing the coolant).

When the gas started to come out I realised my mistake and got it tightened up again. I lost about half the gas and maybe 20 - 30mls of oil. (Fluorescent green).

When I was happy the bung was sealed, I bought an STP air con recharge kit and re charged the system as per instructions. The kit is supposed to include lubricants and a sealer also.

The AC now works fine, indeed it is colder than ever, but there is a harshness in the sound from the compressor. If you switch of the AC the noise stops. It is not exceptionally noisy and you probably wouldn't notice it outside the car but it is clearly there inside. Any ideas?

Much appreciated
Bryan

To be clear, was your AC silent and problem free prior to the accidental gas loss?

Hi Get it recharged properly at AC specialist should cost around £70. The DIY refill kits like those sold at Halfords can seriously damage the system and may be overcharge them. Switch AC off until it's been recharged properly to avoid damaging the pump.

I agree 100% with what Model flyer says. The correct way to service or recharge any AC system is to evacuate the system first, wait for a period to check if there are any leaks under the vacuum, then recharge it correctly with the refrigerant which will contain the correct amount of lubrication held in suspension. As Model flyer said anything else could cause serious damage to the system including damage to the compressor.

Yes get it sorted properly. If your compressor seizes and breaks the drive belt then you are in serious trouble.

do not use AC until you get this sorted properly. Those DIY kits are crap.

Thanks for all the replies! Got that done today, indeed the system had not been correctly charged, but did contain enough oil.

The noise is still there however! I don't think it was there prior to the leak, no. It stops entirely when you switch off the AC. It is audible inside the car but not really outside. The AC place said it could be a pulley/bearing elsewhere on same belt but I'm not convinced - it stops immediately and completely when I turn off the AC.

Any thoughts on further diagnosis?

Appreciate the help.
Bryan

I agree it can't be a pulley or bearing elsewhere if the noise stops when you deactivate the A/C pulley clutch (aka turn AC dashboard switch off).

I think the AC guys thoughts were that the load of the compressor could expose a worn pulley/bearing elsewhere on the belt.

To that effect I poured a small amount of water on the belt with the AC on and the noise stops momentarily - more water and it stops again.

Might this suggest an issue with another component? Not an internal issue with the compressor?

Could be a worn pulley bearing. Cheap part but if you can't diy, labour cost can make a replacement compressor seem just as reasonable.