Chrysler Repair: Mitsubishi A/C not providing cold enough air, mitsubishi galant, metal shavings

Question
QUESTION: Hi, I have a 2001 Mitsubishi Galant which I just purchased about a month ago.  The A/C isn't blowing that cold.  A mechanic looked at it quickly and put some R134a in it (since it was a little low) but it still isn't blowing that cold.  The other day for example, it was almost 80 degrees outside and the temperature at the center vent was mostly around 68 degrees.  There was a point where it was blowing at 56 degrees but it only stayed there for a couple of minutes and then went back to 68 degrees.  The other day it was 90 out and the A/C temp was about 77.  Today it was 60 out and the A/C temp was 44.  The A/C was always in recirculate mode and I heard the compressor kick-in every so often and the fan was set to speed 2.  When I set it to 3 or 4 the temperature would go up about 10 degrees (I guess because it was adding in warm air).  Also, the A/C temperature didn't change much when I was idling as compared to when I was driving.  Also, the low pressure line under the hood was ice cold.  Other cars that I have had had very cold A/C's.  Is it possible that this model car just doesn't blow as cold as other model cars?  I read on the Internet that sometimes metal shavings can partially block the line and divert the cold air.  Could this be the problem or do you have another suggestion?  Thank you for your time.

ANSWER: Hi DJ,
I don't have any direct experience with the import cars so I can't suggest anything specific to that model. If I come up with something I will send you a revised answer.
Roland

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QUESTION: Hi again, I realize that you don't have any experience with import cars but I will ask anyway just in case you have A/C experienace with other cars.  My mechanic said he removed all of the refigerant and filled it up again with the proper amount since he thought that is was overcharged.  It does blow a few degrees colder but it still isn't that cold.  Yesterday it was about 75 degrees out, but the A/C temp was about 55 degrees at Fan Setting 2.  At Fan Setting 3 the A/C temp is about 60. At Setting 4 it is about 62. That is without recirculation on.  When I put it on, the temp goes up about 2 degrees or so which is strange to me since it should go down.  The A/C compressor seems to be cycling normally.  There is something else that I noticed that may be causing the problem.  When I first start the car and put the A/C on it blows pretty cold...about 45 - 50.  Then after about 3 minutes or so the temp goes up to 55.  Also, when idling, when I just put the vent on (no A/C) the temperature of the air coming out of the vent is about 90 degrees (even though it was only 75 degrees outside).  The temp control was on the coldest setting.  Now I am thinking that possibly once the car heats up after 3 minutes the A/C is working very hard to try and cool that hot air that is coming in.  If this is true could this problem be Heat related...such as a blockage causing extra heat to come into the car? By the way, do you know how much refrigerant this car should have? Any advice or suggestions would be greatly appreciated.

Answer
Hi DJ,
I can only guess because of having no specifics about the Galant. The one possibility I thought of is that the blend air door which varies the mixture between air passing over the cooling coils and air passing over the heating coils is not positioned properly such that it is biased toward pushing air over the heater coils more than it should be when you have the AC on. So you might want to look into that door's control situation to see if it is capable of movement over its entire range of motion and where it is sitting when you position the temp lever in various settings. That is the alternative explanation to their being an extra source of heat. Most AC systems do allow the heater coils to be warmed up even when the AC is selected, but they just bias the air flow away from those hot coils to a lesser or greater extent, which is how the final temp you ask for is provided, as a mix of hot and cold air. The door position is driven by a gear which is either electrically controlled by an 'actuator' or mechanically controlled by the temp lever with a cable.
Roland