Noisy air conditioning compressor in 1981 280SL

[Fishead]

Greetings!

I have a fabulous 1981 280SL, Euro-version MB but the one thing that bothers me is a vibration and kind of groaning noise (can be pretty loud and obnoxious) when the air-con is switched on (compressor engages) and at rpm's of 14K, 28K that I've noticed. Probably does it above those rpm's, but I generally don't go that fast to notice. What might be the problem? Anyone have this situation before? Thanks.

 

[Francois]

On my '83 380, it was the wrong gas (R22 instead of R12) and not enough lubricant in the gas. After regassing it was a lot quieter and now only sounds like an extra V8 in the bonnet and not like Harley from hell...

I think the reason it is still a bit noisy might be because of damage from the wrong gas and/or lack of enough lubricant.