AC stopped working - large leak?

[Leafsrule531]

The fun (misery) never ends with this car. I always was aware that I had a leak in the system because I would have to put in a new can of Freon every summer but it looks like the leak has gotten really big.

I reacharged it last month noticed The other day my ac stopped blowing cold air - I put in a can of Freon and noticed that the pressure was at zero which has never happened before. When I put Freon in I noticed that the pressure was going down pretty fast.

I don’t have much knowledge in ac related work. Is my compressor bad or is there a leak in the system somewhere? Any thoughts on where I should go from here ?

When I did put in the new can I noticed that one of the vents was blowing cold air (the one closer to driver side) so assuming the compressor is still good and there is a leak in the lines somewhere.

[bigjae46]

Probably a leaking evaporator. Dash and support bar have to come out.

[TexaZ3]

Do you smell refrigerant inside the car? If so, your evaporator failed - very common issue on E46 in general. Also could be a number of things - from failed o-rings on various lines, etc. Best to take to HVAC specialist so they could pull vacuum on the system and pinpoint where it leaks. Or you could be chasing it forever. Btw, do NOT try to put more refrigerant in the system until you figure it out. It is very harmful for the environment, and you should not be letting it go to atmosphere freely.

[Leafsrule531]

That would be a real bummer since I literally just had my dash out for an interior swap. It's a pain in the ass to remove. Agree to not putting any more Freon.

Any recommendations on hvac specialists in NJ ? Can I take it to a regular bmw mechanic ?

[TexaZ3]

That would be a real bummer since I literally just had my dash out for an interior swap. It's a pain in the ass to remove. Agree to not putting any more Freon.

Any recommendations on hvac specialists in NJ ? Can I take it to a regular bmw mechanic ?

You don't really need a BMW specialist for HVAC work - they are all the same pretty much. Just find a reputable shop in the area, they should be able to pinpoint it.

[Icecream]

I'd go to a specialist. Had a shop pull vacuum with I think a snap on system that detected no leaks (even though like yours it leaked every season). Sure enough, a couple months later it was blowing warm again.

[Arith2]

I'd go to a specialist. Had a shop pull vacuum with I think a snap on system that detected no leaks (even though like yours it leaked every season). Sure enough, a couple months later it was blowing warm again.

I leak test never works on those machines. Wasted feature. The Mahle R1234yf are a nightmare to deal with.

OP, put some dye in the system, get a UV light and some of those yellow UV glasses. If it's leaking, it'll be super bright but I would also clean every area where there could be a leak first. Run the system for at least 15 minutes and check all the connections. Also check where rubber hose is crimped to aluminum. Scan every square inch of the A/C system you can. Check the service ports, clean them out ridiculously well with brake clean and fill with regular water. Inspect to make sure there's no dye or very little then do your other checks and come back to the ports. See if a bunch of dye is floating on the water now. The dryer should also be replaced once you figure out and fix the leak. That prevents moisture build up in the system which can cause corrosion and wear on the compressor. It gets saturated over time and when there's no pressure in the system, typically it's only good for a few hours with an open and empty system.

If no leak is found, wait until the system goes from cold to warm and then check again. Easy way to do this is to have a shop fill your system and add dye for a later diagnosis. Freon is just a brand. R134a is the refrigerant you're putting in by the way. Also PAG46 oil should also be used. You don't until you know. I typically add an ounce or two of oil if the system has been emptied. Do pay attention to the fill capacity very closely. This pickle may have happened because it was overfilled. There should be nothing in the system when you fill it so you know how much you put in. There's only a plus or minus 15g allowed.

[sapote]

The front mounted condenser is a good target for flying rocks and other debris, so I would remove the efan and take a look.

When I installed the Mitsubishi Mini Split heat pump system for my house, the system must be evacuated with vacuum pump down to 500 micron Hg (see level atmosphere pressure is 30" HG or 762000 micon HG) and it should hold at this vacuum level for 1 hour to be qualified as no leak. In fact I was able to pull it down to 100 micron with perfect hand made flared joints for the refrigerant pipes.