twssas

A little background, last summer (August) did a drive of about 2 hours in duration, in a high temperature, high humidity environment. On the return home on that drive, the A/C slowly began to warm up, and eventually quit cooling all together. The fan continued to give it all it had, but no cool air. After stopping for gas, A/C began to blow cool again (albeit not as cool as it should have), then eventually quit blowing cool air again all together.

Did some searching on various boards and found a BMW TIB that identified an issue of A/C stops cooling after long drives, specifically in hot and humid conditions. The fix was to reprogram which ultimately changed a temperature setting on the evaporator to keep it from freezing up. ( SIB 64 04 05) http://www.bimmerfest.com/forums/sho...hlight=cooling

So....went to the dealer, took a couple of days to do the reprogramming....got the car back all seemed good....

However, most of wifes driving in this vehicle is in town, 15-20 minutes, shut car down, start up later, repeat same.......all short durations.

OK, fast forward to yesterday....high temperature, high humidity. Drove a couple of hours in the morning, A/C felt fine, finished our visit about 3 hours later, headed back.....same as last year....A/C slowly stops cooling, but keeps blowing....getting warm.....beginnning to grumble, and as events often happen, stopped at the same gas station as the year before, got gas, and started off again, with some air, not real good, but some.

Getting closer to home now, and stopped at a light. Hot, uncomfortable, and grumbling.
Older Honda Civic in lane next to me....and you could see the cold air blowing the girls hair in the car. And here I am, sweating. So grumble some more. This by the way, is the first time since the program upgrade, that wifes vehicle was back out on highway for an extended period of time in hot and humid conditions.

Get home, park the car in the garage, and start searching on the boards again for additional info on A/C issues. One thing I notice, after the car is parked, there is no condensation underneath on the concrete floor. So I do some searching for that.....seems that there is some mixed results from owners whether or not they even see condensation from the evaporator drain.

Went out to car this AM, started it up...and the A/C will freeze you out. Certainly working today.(at least in the garage) Went out this afternoon for a short drive around town, A/C appeared to be OK....(nothing to brag about). came home, parked it and looked under the car for evaporator condensation. The concrete was dry as a bone. I also have a Acura MDX, the A/C will leave icicles on you, and when parked in the garage, a small lake appears under the vehicle. I think I am getting paranoid about the BMW A/C.

Going back to the dealer next week....my question.....any experiences similar? Is there a condensate drain from the evaporator to drains out on the floor? (again have read conflicting stories on this....some say yes, some say BMW has design that eliminates the moisture in another way.....).......

Which all this leads to is my lease is up in December, and am/was/will (thinking now) of ordering another one for wife. That is why I am asking about experiences. This seems relatively isolated......but.................as wife was saying yesterday...while watching the girl relaxing in the cool Honda Civic........."just go buy a Civic." (she doesn't really mean it though)

Any thoughts?

530inOK

I found this on another forum. May explain why there is no condensation puddle. I haven't seen condensation under mine either. And the part where the blower motor is going for all it's worth and
little air coming out the vents has happened to me as well. Maybe the evaporator is freezing and this is some form of defrost mode. I've read about similar problems on this forum but remain
puzzled as to what's going on.
Hopefully an AC expert will chime in and set us straight before CIVIC envy gets the best of us!
Keep us posted if you find something.


Update... The dealer mechanic says that the new 5 series have a full shield underneath the car to improve aerodynamics (I knew that)... and the water does drain from the evaporator down onto the top of the shield as opposed to dripping onto the ground directly. Unless the volume of water is quite large, it just evaporates off the upper side of the shield and may not be seen at all on the ground.

They say that unless I'm experiencing wet carpets or other signs of leakage in the car (I'm not), its working as designed.

In looking more closely at the underside shield panel, it seems somewhat porous, and as such probably absorbs the draining water and it just dries out through evaporation rather than dripping on the ground.

I would have probably designed it to route the drain hose through a small hole in the shield and let it drain directly to the ground.
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2008 535i (Delivered 3/8/08) : Plat Bronze / Black Dakota / Premium Pkg / Multi Contour / Light Poplar Wood / Logic-7 / Sirius