Noisy AC pump, help!

[240-singh]

hi guys. have owned my 1999 w202 240 sport for a week now, loving it so far but from start up there seems to be a deep low hum when the AC is initially switched on. It lasts for about 1 minute or 2 and then dissapears. Sounds like the AC pump to me but is it supposed to be that loud? its not discrete at all. any info would be excellent.

Thanks.

 

[Vlad]

Hard to diagnose on a noise alone, but all I would say is that normally when the compressor gives out, its starts with the compressor clutch clattering away to itself.....can go on like this for ages before it fails.

If your air-con is working, ie ice cold and the noise goes away after a couple of minutes then I would leave it alone

May be worthwhile getting the system re-gassed as the noise you describe could also be down to lack of gas in the system, but then you would be hardly getting any cold air anyway.

If you need a new compressor it may be worth contacting this lot as they are much much cheaper than buying a recon item from Mercedes and its much safer than buying a second hand one

http://www.compressortech.co.uk/index.html

 

[240-singh]

humming sounds from the rear.... HELP!

actually guys, i switched the AC completely off whilst driving a while ago and the noise is still there and actually sounds like its comming from the rear. so i was mistaken when i thought it could be something to do with the AC. what could this be? it sounds like some kind of fan comming on and then turns off after a while. just sounds like a deep "hum". has any one ever had this experience?

 

[Carrotchomper]

My old BMW had this noise- You could only hear it if you listened. Not sure if yours has it but mine was the self-levelling rear suspension sorting itself out.

 

[240-singh]

My old BMW had this noise- You could only hear it if you listened. Not sure if yours has it but mine was the self-levelling rear suspension sorting itself out.

i see, but surely self levelling shouldnt take longer than a few minutes? hmmm... any one else out there hearing a similar humming noise? it comes on now and again. cant really be noticed that much whilst driving but at a standstill it can definately be heard. i just dont want to keep driving it just encase its a problem which i need to get looked at. but if its normal i'll just leave it. it litterally sounds like fan which switches on for a few minutes then turns off. cant be right surely??