On my E 320 the driver side blows warm air but the passanger side is nice and cold, I took the car to dealer twice and each time they said it needed freon and it's fixed now. They even checked for leaks with dye and did'nt find any. I suspect that a flap must not open or close somewhere in the system but I don't know where. Any help would be greatly appreciated.
P.S. Why the service dept. at most of the dealerships sucks??????!!!!!!
Andrew

 

check the monovalve...some motor have dual.the part have the coolant go past one of the valve and the other still working ,the best way is to replace the new one ..dont buy the junk yard one .they have the update part.