Was getting warm air out the vents so had AC looked at by dealer, found failing expansion valve and seals, replaced. Drove it a few days, same problem. Blows cold first thing AM today but a couple days ago on an 85 degree day pass side was blowing 65 degrees and drivers side 70+ degrees. Not adequate. Took it back in and was told now the mechanic thinks the condenser is plugged and that was messing up the expansion valve, so if we replace that it should work. They are very unsure of why it would be plugged or contaminated internally, some question if something could have happened during engine replacement a couple years ago. Is this a very rare problem? I know nothing about A/C systems.