Okay, so yesterday I took my 2007 E63 on the longest continuous trip since I have had it (600 + miles), and the climate control system started to do the weirdest thing. I had the vents set to blow onto the face through the vents above the climate control settings, and had the temp set on 'MAX COLD', so it was blasting out the vents very hard just like it should. After a while I started noticing that the air did not seem to be coming out of the vents very hard. In fact, it was barely pidding out of the vents. The odd thing was that you could hear the air blowing very hard inside the dash, but it was like someone had closed off the vents. I tried using the dial that opens and closes the vents, and when they were closed no air came out, but on full open it was just the piddling of air, not the hard blast it had been.

Here is where it gets odd. Feeling that maybe since this car probably has more electronics than the first space shuttle, I did the whole 'Microsoft Windows fix', I shut the car off, let it sit, and 'rebooted' (i.e. restarted) my car. Well, that worked....for about 20 minutes. This moring I went out and started the car again and full power on the air at start-up. It is almost like something is getting overheated electornically and shutting down the directing of air to the vents after it runs for a while. Even turning the dial to redirect air to the window vents, foot vents, or any other vents, fails to work after it has been running for a while. You can hear the air moving very fast behind the dash, but it is not going anywhere. Any ideas? I am in Canada for several days and would really like functioning A/C.

I love this car, but am getting pretty fed up with having to keep going back to the dealership every week for something new.

 

Does it only do that when it is set to "max cool" have you tried the other settings like auto. Maybe your right it might be over heating, I keep mine set to around 70 degrees on the auto setting and that does really well in temps over 100 degrees on the outside.

 

Sounds like you are freezing up the evaporator.

Why do you set it at max cool?

Mine has been set at 72 for 5 years never had to change it, works great, 105F & 100%RH

 

Your evaporator is freezing over. I guarantee that if you turn off the a/c and just run the fan, you will still receive cool air until the evap unfreezes, then you can turn the a/c back on. It won't fix your problem, but it will be enough to last you until you can get it back to your local dealer to be checked out.

Call up your hidden a/c menu and post the reading for #5 the next time you have a problem. I believe your E63 has that menu, but you should use the driver's side AUTO button instead of the REST button as mentioned in the hidden feature's thread.

 

wow...that's never good. No trouble here (knock on wood).

 

Thanks for the feedback. In response to a few of the points:

1.) I had it on 'MAX COLD' because it was really hot here, and that was just the setting I chose. Most of the time I will have it set on a particular temperature other than that.

2.) With regards to if it does it on other settings, yes, it does. I tried other temperatures in the 60 - 69 degrees range and still had the issues with the air not coming out of the vents, no ability to adjust which vents the air came out of, yet being able to hear behind the dash that a lot of air was being produced. It was just like all of the vents were closed and the air had noplace to go.

3.) As far as the hidden features thread, I will have to look that up and see how it pertains to my A/C system.

I am kind of at a loss on this, because the two times it has happened were when the system was on for around an hour or more previously, which makes me think duplicating it for the dealer to troubleshoot when I get home may be difficult. Yet I cannot have this issue with the climate control since we take long trips back and forth to Canada routinely (1,200 + miles round trip), and with my barely 1 year old daughter in the car, I do not want to risk driving in sweltering heat with no relief for her.

 

I had a similar problem yesterday in the E63. It got hotter and hotter in the car and the a/c couldn't handle it even with max cool. Turned out that the rear seat unit was on max heat and when I put my hand back there it was unbelievedly hot. When we put the rear on a/c the problem was solved. Our granddaughters were in the back seat the night before and were complaining of being cold. Guess they solved the problem by readjusting the rear system.

 

I had something similar happen to my E55. Can't remeber the name of the part, but it had a leak (freon) and had to be replaced and freon recharged. Reason AC went full max was because it wasn't cooling and called for max AC. But my AC would not come on again afterwards. Also, leaking part not covered by extended warranty unless compressor also replaced.

 

Since his a/c works fine after shutting off the car for a while and coming back, he does not have an issue with being out of freon.

 

So I drove home yesterday (11 hours) with intermittent stops and the climate control set between 69 and 72 degrees and did not experience the issue again. It seems to be when the controls are set on their coldest setting for an extended period of time. How should I go about having the dealer inspect it? Are the codes stored by the climate control computer for failures or situations like this?

 

I had a similar problem about a month ago; a/c was not cooling properly on a hot day (100 degree F) after driving a while on the highway. I was not on max, just had vents pointing to the dash, temps front/rear were at 65 degrees, blower was at position 5 or 6. Center vents were very weak regardless of center dash knob position, and air was not especially cool in either regular or recirculate mode.

I had my dealer check it, they found that charge and pressure were both low. They did a leak test, replaced R-134 and added dye, and also replaced a high speed fan regulator in the dash which had thrown a code. Mine is better, air is much cooler, probably as good as it ever was in any W211 I have owned, but the a/c in my SL is a lot better.

You might also want to replace your outside cabin filter, mine was very dirty when I bought the car last year and I'm sure it impeded flow too.