'82 240D A/C and Operating Temp questions. - PeachParts Mercedes-Benz Forum

frnorke · #1 08-05-2010, 03:03 PM

My A/C was charged by the dealer a couple of years back. It worked "Okay" and had cold air coming out of the vents. Since then, it's no longer blowing cold air, just hot warm.

How would I go about trouble shooting the system? I believe there's a leak in the system. Can someone recommend gauges and leak detection system for a '82 240D?

Also, what is the proper operating temperature for a '82 240D? My temperature gauge is all over the place between 80 degrees Celsius and 120 degrees Celsius. Sometimes it goes over 120. I almost never have a constant 80 degrees celsius (which I assume it the normal operating temperature).

Thanks for your help and suggestions.

dagObx · #2 08-06-2010, 01:52 PM

I can't help you with the operating temp of your car, but I'm sure others will chime in.

As far as your AC system goes, did you retrofit your AC to R134a? If so, that may be part of the problem. Our older cars are designed to us R-12, which is available relatively inexpensively from Craigslist or Ebay. It costs more that R-134a, but will allow your AC system to operate properly. R-134a is also very hard on compressors as it raises the head pressure to pretty high levels, causing premature death of the compressor. If you don't know if your system was converted to R-134a, ask the dealer what he put in your car.

Hopefully, LarryBible or Vstech will chime in with more help for your AC system. Your motor temps sound out of whack, probably from either a bad T-stat or clogged radiator (inside or out). You might try washing the radiator out from the outside to get the crap that has built up between the fins over the years. That might help...