AC squeal at idle - York compressor - PeachParts Mercedes-Benz Forum

rgnprof · #1 04-14-2006, 06:52 PM

I jsut got my AC running on my '78 300D - cools fine and no leaks. That's the good news. But, I have a squeal/screech periodically at idle and the belt will actually stop running periodically - for just a fraction of a second at a time. I changed out all the belts and I have tightened that AC belt about as tight as I can.

When I am driving the car I don't notice any problems, just at idle.

Any thoughts?

Ryan

Matt L · #2 04-15-2006, 10:37 AM

Ensure that you didn't put too much tension on the belt during this encounter. That will cause all sorts of problems that you don't want.

I would suggest trying some belt dressing on that one. Don't go overboard with the stuff, as a little goes a long way.

RJH · #3 04-15-2006, 03:20 PM

I have the same problem on my 79 - 300d - I was told it is either the AC clutch bearings going bad or the AC compressor. I am going to replace the clutch and see what happens. If anyone is parting out - I need the climate control panel for the above mentioned mbz.
Ron

kitchenrat · #4 04-15-2006, 05:11 PM

put ac guages back on and see where high side pressure is when squeal occurs, system may be overcharged, particularly if you've converted to 134a

rgnprof · #5 04-15-2006, 10:23 PM

I did NOT convert to R134a and I'm sure the guy who did the evac and recharge knew what he was doing.

Actually, I decided to tighten the belt further and the squeal is gone - at least for the time being. I noticed while looking at the belt while the car was running that it was really 'flopping' around, especially noticeable on the lower side of the belt - from the AC compressor to the crankshaft pulley. I think checking tension on these belts is hard to do by feel, and it would appear they need to be very tight.

ryan

tangofox007 · #6 04-15-2006, 10:33 PM

Quote:

Originally Posted by rgnprof

I think checking tension on these belts is hard to do by feel.
ryan

Having just purchased a belt tension gauge this week, I can confirm that observation.
When I increased my compressor belt tension to the specified 40-45 Kg, the compressor quit making the pinging sound it has been making for years.

Palangi · #7 04-15-2006, 10:35 PM

Could it be that the compressor itself is flopping around? As in, maybe it needs new rubber mounts? Check with RLeo on this. I think he replaced the mounts on his a while back.