stevebham01

In the afternoon or after work when the outside temp is over 90 degrees the AC has trouble cooling the car down. I set the AC on max and the lowest temperature setting for the drive home. In traffic it takes a while for the AC to start cooling. Once I get onto the expressway the unit starts to cool. During my drive the AC will automatic turn itself off the MAX AC setting and the fan speed sometimes slows down and changes to regular AC with recirculation. The AC compressor turns off and warm air comes thru the vents.

The compressor cools to 40 degrees on the way to work with no problems.
I took the car to the dealership the suggested I replace the climate control unit.
I replace the climate control unit and I still have the same problem. Help!

tonyb635

Maybe have the freon level checked. I know with my 08 535 I have a similar issue when its really hot outside. It does take a little while, 3-5 minutes before the air coming out feels cold and then just trying to cool the car. It is one of the lacking things about this car that i don't like. I purchased a windshield dash heat deflector last year and this seemed to help a lot.

stevebham01

I agree with you that is the one thing that is lacking. It does not help the car is black on black.
July and August in the south is brutal without a fully functioning A/C.

The Freon level was my first thought too.
That was the first thing I asked the shop to check. They checked the levels and added a small amount of Freon but the problem still happened.
It is almost like the car is getting a signal to turn off the compressor once it starts to cool the car off.

tonyb635

Yeah, mine also seems a bit delayed, however, once on the highway or after a few minutes it blows cold and it needs to be turned down. It's just that common startup issue when the car sits in the hot sun. I imagine it could be a lot of things contributing to this issue. Heat seams to allow the ducts to heat up a bit much which then would have an effect on the air coming through. I think this because the car doesn't perform like this in the spring and fall. When I install the heat deflector in the windshield this seems to help a little. Sometimes I feel the AC is not on during this hot time, bit it is. It just seems to takes it sweet little time to start blowing cold air. None of my other BMW did this and my current X5 blows cold almost instantly.

stevebham01

stevebham01

Tony

I agree
I have left a thermometer in the vent to determine if the A/C is blowing cold and the compressor is working properly.
In the mornings the car blows 40 degree ice cold air thru the vents. When I get off work in the afternoon and the outside temp is over 90 the thermometer is reading well over 100 degrees.
It takes a little while to cool off and start cooling the car. I will try a windshield reflector hopefully this will help.

The main problem is the car has a mind of its own and turns the climate control from Max AC down to normal by itself.
You can smell the condensation coming thru the vent other times like the compressor has turned itself off some times.

Has anyone else experienced this problem?

bgreaves

Did you check everything? Dont want to assume you didnt do this already, just making sure. Go into the iDrive system>Temp control. In there, you will see an indicator that lights up in red and blue. Make sure that in the summer time, you turn the iDrive knob to make all the blue bars be at max. On the dash, just hitting the Max button is fine, but if you don't hit the recirculating button so that the amber light on the left appears, you won't have the air in the car circulating and will only be trying to cool the outside air that's coming into the car. By recirculating the inside air through the system, you will cool the inside of the car much faster.

If you did all of this, then you def. got a problem. Hope this helps.

Wolrab

Is your battery healthy? These cars have many strange and arcane ways in which a weak battery can manifest itself. Seems an unlikely cause, but easy to check.

stevebham01

Question #1

Yes I have set the I drive program for all blue bars and have shut off all vents except the center vents across the dash.
As for the recirculation button it is illuminated on Max AC so that the air gets recirculated.
Thanks

Question #2

The last trip to the dealership on the battery cable recall they kept the car over night to test the battery.
They said it check out OK. I have read that the car will turn off auxiliary components if it detects there is a weak battery.
As far as I know it has the original battery.

I also read that the AC compressor runs full time once the car is started. Can anyone confirm if this is true?

Wolrab

It's a clutchless compressor. I think that means it's a radial piston pump with variable stroke, so it "runs" all the time, but doesn't necessarily pump all the time. If I'm getting some details wrong, I'm sure somebody will correct me.