intermittent AC operation in stop and go... - Benzworld.org - Mercedes-Benz Discussion Forum

harriscommissioner · 07-20-2008, 04:37 PM

driving.. no issue at freeway speeds.... I am referring to cold air not a problem with air flow. thoughts?

79Mercy · 07-20-2008, 06:35 PM

look and see if the clutch is cutting in and out while it is idling.

unitfreebie · 07-23-2008, 12:40 AM

Yes.. do the above post check... and also could be low on R134a as in stop and go the engine rpm is lower causing the compressor pressure to fall below the pressure cut off limit... thus cutting off the compressor.

Put a thermometer in the center vent... if it does not read 60 degrees F at idle or 50 degree F at 1500 rpm, then add a can of refrigerant to the low side of the AC system.

If you have the AC gauges.. the low side should read about 25-30 psi and around 150psi on the high side. If the low side reads lower than 25 psi, then add a can to bring it up while watching the temperature gauge drop as the can is added to the system.

Good Luck ..