A/C mystery leak

Last Friday when the temperature was about 95° in the shade my air-conditioner suddenly quit . It was blowing hot air from the driver side and the left center vents and slightly cool air from the passenger side and the right-hand side center vent. I took it into the dealer and they looked at it and said it was out of Freon. They recharged it, kept it overnight and said they could not identify any leaks and it was holding a full charge. I understand that over time all air-conditioning systems leak a small amount of freon, but the car is only a year old with just over 13,000 miles and it seems unlikely that it all should have leaked out in this short period of time. I suspect I'll be back with a dead AC system in a few days to a week. Is there any place that it could be leaking that would be difficult to find?

when my 135i had a leaky evaporator it took pretty much a year for it to get to the point where it was blowing hot air.

If it is a slow leak, not sure how they'd determine it wasn't leaking (not saying the couldn't, jut not sure how).

Did they put a dye in the freon when they recharged it? If so, something should show somewhere by the time you are empty again.

Yes. The more difficult place to get to is the evaporator. That is in the dashboard. Refrigerant systems shouldn't leak and refrigerant doesn't wear out.

They put the dye in. I asked about the evaporator, they said that it should have leaked overnight if that was the problem.

Vandalism maybe.:shrug:

A number of us in the Houston area, including myself, have had our evaporator cores replaced for this same problem. Those sound like the same symptoms we had. I believe most of us had a very slow leak so I doubt it would show any leaking right away. Replacement evap. cores were on national backorder when mine and several others went out so I waited almost 2 months for one. Not sure what the status is on them currently. A recharge only lasts so long. It ran out after 2 weeks for me. I'd get a proper diagnosis where they have to take apart the dashboard.
Hope you get it fixed soon, good luck.
Edit: Many of ours went out around 12,000-14,000 miles IIRC with less than a year of ownership on most if not all. Was around 12K and 9 months for me.

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Vandalize what? My car is garaged at night, in a limited access parking garage while at work. I cannot see any evidence of vandalism under the hood.

HBTD said:

Vandalize what? My car is garaged at night, in a limited access parking garage while at work. I cannot see any evidence of vandalism under the hood.

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Google it. You asked and I provided a possible scenario. From what I gather from your description it's defect or vandalism.

I googled it and saw nothing about vandalism of car ac units, only home or office ac to get the copper. I think it probably is the evaporator but I'm not quite sure how I will get them to prove it I guess I will just have to wait until it fails.

The evaporator is the most likely cause. The dealer should be able to pinpoint it very quickly if that is the case.

Update
It's been a month now since the original AC failure, I took the car in for oil service last week and had them check the air conditioner charge (it's been working fine since the recharge), and check for leaks. No leaks found and no loss of freon. Any thoughts?

I have the same problem. I will bring my car at the dealership this Tuesday. I'll post some updates.

HBTD said:

Update
It's been a month now since the original AC failure, I took the car in for oil service last week and had them check the air conditioner charge (it's been working fine since the recharge), and check for leaks. No leaks found and no loss of freon. Any thoughts?

Click to expand...

Must be a really slow leak.

It took until January 2017 for the A/C to fail again. The dealer just replaced the evaporator yesterday. Hope this one lasts. Does anyone know if the replacement evaporators are improved over the original?