A/C PROBLEM

THE A/C SYSTEM IN MY 190 2.6 87 DO NOT WORK WELL AT LOW RPM. WITH HIGHER RPM IT WILL START COOLING BETTER. THATS WITH THE CAR IN PARKING POSITION.WHICH COULD BE THE PROBLEM, COULD BE THE COMPRESSOR SPEED SENSOR. THANKS

I would strongly recommend checking the belt tensioner first. I had a similar problem with my 1988 190E. After I replaced the belt tensioner and tensioner damper, the problem disappeared.

I have the same problem in my 1993 190E 2.6(48,000 miles). With the car running, but stopped, the air will not get cool. When I am moving, say driving down the highway, the air gets cold and stays that way until I have to stop. After I stop, the air will turn much warmer. Needless to say, that is not a good thing living in Dallas.

Also, the higher I turn up the fan, the warmer the air gets no matter what speed I am traveling.

Any Suggestions?

[MB STARS]

I think the air condition system is low on freon take your vehicle to a shop have someone check for you......also check the aux
fan operation.

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MB STARS Master Guild Technician,12 years MB tech
5 years independent shop owner

[Tobias MB]

Suggest you go back to Herbie on 8/9/99 and look at the suggestions as the problem is quite similar. Maybe there should be an A/C post during the hot summer months!!

[Benzmac]

Be sure to check the aux fan operation. If the belt allows the compressor to slip, it will lock out and will not cool at all until the key is turned off and on agian. You may be a little low on freon as well.

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Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

I seem to have this same problem on my 87 300e i asked this question before DOES THE AUX FAN COME ON WHEN YOU PUT ON THE A/C OR DOES IT ONLY COME ON WHEN THE FREON IS HOT AND THE CAR FAN NEEDS A LITTLE HELP. ( buy the way this is what a tech told me )

[Benzmac]

The aux fans come on due to a pressure switch that is located in the drier. If the pressure exceedes 260 or so the fan(s) will come on. The older model cars had a green switch that came on around 280 or 300 but the switch has been updated to the red one that is the 250-260 range. It made a big difference in how cool the engine ran with the A/C on too.

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Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM