Lincoln Zephyr – 2006 -120K miles.
Manifold gauges show low side 40-110 and high side 150-190. Ran the car for 25 min and they kept dropping on and off falling within that range. Ambient temp 82 degrees, ac set to coldest possible (60 degrees), fans on high, cabin closed.
Two days ago I evacuated the system and the most I could get was around -24. As soon as I stopped the pump, the reading went to zero. I decided to add refrigerant and stop leak. System calls for 21 oz R-134A. I added 18 oz refrig but could only add partial contents of 3 oz stop leak.
Now just as before - the ac blows warm. Any help will be appreciated.
I decided to add refrigerant and stop leak.
Not a good move. It would have been much better to find and fix the leak properly. "Stop leak" AC products frequently clog up the system internally. In fact a friend of mine had to replace every AC component in his car after using a stop-leak product. Also no shop is going to want to work an AC system contaminated with stop leak since it can damage their equipment, should you decide you want to have a mechanic work on it at some point.
Is your compressor cycling on and off when the gauges are varying or is it running constantly. Does the compressor have a control valve?
