Hi, this past week, my '89 190E 2.6 has been having AC difficulties. One day, I started the car, the air was on and all was fine. Drove across town and back, no problems. The car sat for about an hour, restarted and drove...no AC. Came home and popped the hood, compressor was not running. Waited about 2 hours, restarted the car, AC working fine. yesterday, same thing...I stuck my gauge to it and it has the correct amount of 134a in it...the electric fans work...the blower works fine.
Last night, I was driving around just listening to it...when I turn on the air, it's cold for a minute, then i hear a "bark" sound and it kicks out. Stop the engine and restart several times and it does this several times...all with the same bark sound...is my compressor trying to lock up?

From what you describe sounds like it mite be the clutch.

How difficult and how expensive is a clutch??? i'll try anything once
I usually do my own work.
thanks
greg

Don't replace the clutch on my guess that would be foolish without further checking it out. Go here http://www.aircondition.com/ and you should be able to find some qualified help.
Good luck
Rdanz

with the car being 15 years old I'd about rather replace the compressor anyway if that is the problem. I went to the AC forum and posted...we'll see what happens

Replace the belt and tensioner -- cheaper than a new compressor!

There is a speed sensor on the compressor, and it if slows down, the Klima relay will drop it off and leave it off until the engine is restarted. This is to protect the belt since there is only one, and you will get severe engine overheat without a fan belt.

I would also check the fuse for the aux fan -- if bad, the high side pressure can go pretty high, cause the belt to slip, and shut the compressor off.

Sadly, it could also be a compressor on the way out.

Could also be what happened to the "spare" I'm working on -- front seal leak caused the rubber in the clutch to fail, so compressor won't turn properly. That would account for the "bark", too. Won't last long, the rubber shreds.

I'd check the belt first, since that is more likely to be the problem than anything else. A dead belt tensioner will let you run so long as it's fairly cool, but let the belt slip as it heats up.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!