AC not cold on driver side during idle.

[bruce1ay]

I have MDX 2011 with A/C problem:
When idle, the driver side is not as cold as passenger. Once, I pressed the gas to reach 2K RPM, then it starts to blow cold air. Please help.

I brought the car to A/C shop and test for leaking (vacuum) and fill up the freon and still got same problem. The mechanic said no leak. He is guessing that it is the expansion valve. Is that true? I want to get second opinion before I fix. Please help

FYI, also I replaced the relay since it is a common problem for MDX but no help. Any idea would be appreciated. Thank you in advance

[Cusser]

I'm not agreeing about it being the expansion valve - there's only one, and since passenger side is cold, it's working. I think that one of the flaps/doors in the vent system is not closing/opening properly for the driver side.

[Tom Greenleaf]

? So it's not a refrigerant issue is what a tech would rule out first now on to basics IMO next. Does this have a cabin air filter that could be dirty? Passenger's side being colder is somewhat normal just the path of air ducts is shorter will get the most available first. How RPM can solve this suggests it's not properly exchanging heat at evaporator may be from the one X valve or just isn't compressing enough refrigerant without faster RPM pressure and temp checks of lines would be helpful now IMO and may only have a low pressure port good old touch and feel or thermos on lines can tell what's going on inside the lines to evap about as well. May need a dealer if a repair of and has dual controls for passenger and driver's side for full details of layout. Do see if you have a filter and that it's good or not if never touched in a 2011 now should have had a new one by now or a few?