AC still not cold after installing new expansion valve and receiver/drier

[rmr2122]

I have an 87 325i convertible and am trying to get my AC system up and running again after the PO let it sit unused for a number of years (not sure how many). I replaced my expansion valve and receiver/drier and the system holds good vacuum. I charged with 2 cans (2lbs 4oz R12 equiv) of FrostyCool 12a and am getting cool-ish air from the vents but definitely far from cold air. Cooler than before I started this project but not acceptable.

What should I turn to next?

[roguetoaster]

Check belt tension/compressor operation, see if it's running more or less than you think it should. Clean your condenser, and the evaporator if you can get in there. Make sure you have good airflow over the condenser. Make sure your blower fan is actually moving a good amount of air. Check your mixing flap/seal. See if there are large air leaks in the HVAC box. Make sure you aren't icing up anywhere. Replace your worn out compressor if all else fails.

[ADEN]

Expansion valve rarely fail in E30s mine worked after 10 years of no A/C lol.
As @roguetoster mentions clean evaporator and condenser from outside using compressed air and from inside with a special solution assigned for ac system cleaning (inexpensive) then i advise you to use synthetic oil for R12 compressor this is what worked for me. You can use the oem oil too if not expensive important point you need to fill the system with enough oil since your system is dry from being out of service for years.
another problem that came to me when fixing my ac was air recirculate air wasn't 100% still getting air from outside although my recirculate button is pressed and i also opened my motor and closed the flaps and seal them when i go to high temp 45c places i close my placsic vents next to the wiper arms lol i know it is stupid but gets me cold air inside.
Wish you luck..

[ZeKahr]

Eh it’s normal with German cars to have weak AC, especially ones as old as the E30. In Germany they don’t understand the concept of heat and humidity because their climate doesn’t really have those things except for a few days of the year. They design their cars for Germany first, and everywhere else second. As a result of that the AC is an afterthought.

My E30’s AC isn’t currently functioning, but my E46’s AC is sufficient (and not any more) in the 80s but barely feels cold once the temps hit the 90s - my back starts sweating when its in the 90s. And that’s when its on recirculate. Every single BMW I’ve sat in had AC that felt like this.

You could do a couple of things to get the AC to blow ice cold:
- force the aux fan to run on high at all times. Easiest way to do this is to short the hi speed switch for the fan (free). This keeps the condenser much cooler.
- run the AC in recirculation mode at all times (free). The AC has less work to do by sending already cold/dry cabin air thru the evaporator vs having to cool hot/humid outside air.
- Upgrade to a parallel flow condenser (about $100). More efficient than the tube and fin condensers that came standard on the E30. Note that these cannot be flushed unlike the tube and fin style condensers
- Upgrade to a Sanden compressor (WARNING: requires fabrication for the mounts). More efficient design than the E30’s factory compressor
- Get a heat-blocking window tint installed all around. I’m running 3M Crystalline 70 all around; it blocks about 50% of the sun’s energy while letting in 70% of visible light. Drastically reduces the amount of heat the AC has to remove from the cabin. Cops will not give you any trouble if you go with a tint this light. Cost me $900 to do Crystalline all around (incl windshield, it is IMPORTANT that you tint the windshield since that and the rear window are where most of the sunlight enter the car).

[cory58]

my E46’s AC is sufficient (and not any more) in the 80s but barely feels cold once the temps hit the 90s - my back starts sweating when its in the 90s. And that’s when its on recirculate.

There is something wrong with your E46 AC. My wife's DD was an E46 and it would freeze us out in the middle of summer. We lived in Ft. Lauderdale, Memphis and Charlotte with that car - plenty of high humidity and temps over 90. I added some 134a once in 170k miles and it still worked great on the day the autobox failed and I retired the car. I also just bought a 2000 M5 and the AC is the same - will freeze me out at 93 degrees ambient. BMW had figured out AC by the E39/E46 generation.

Cory