Drgolf131

Situation: While driving back to Dallas from Galveston a couple of weeks ago, my air conditioner started acting up ... Despite being set on 70, the temperature was gradually getting warmer. It also seemed like the defroster was blowing air, even though it was set on regular a/c function. The context was that I had been driving for about 3 hours with the Distronic set on 80, the outside temp was about 104, and the system had been working perfectly. I got off the interstate and pulled into a gas store, and when I did the system gradually began blowing cold air again. The system worked perfectly the rest of the way home ... It seemed like the a/c had frozen up and stopping let it thaw out. Car is 6 months old with 5,000 miles and I have not had any problems at all.

Anyone experience a similar situation or have any input?

avisys

Sounds like the evaporator froze up.

Did you have it on Recirc? (Inside air) If so, that could be the problem, rotating that same damp Dallas air through the system until it all froze up.

Drgolf131

It was not set on recirculate ... Set on Auto, which I'm assuming was pulling outside air in ... Interesting thought.

MCF

I live in Houston. It has happened to me twice but it was only the driver side vents that got warm and volume was greatly reduced. Happens once driving North after about 20 minutes of driving and once driving South after about 20 minutes of driving.

hyperion667

sounds like you should just start traveling East and West

Drgolf131

LOL! One thing I thought of is that I've never driven any previous car for so long at 80+ mph ... Nice to have the speed limit go to 75 just as I got my E350!

MB500

AC in my e350 has even more bizzare behavior. I leave in Southern CA so it gets pretty warm inside the car. Every time I set AC on AUTO the AC fan starts working at its highest speed, the way it should to cool the interior down. Only after working for 2-3 minutes at its highest RPM, the fan drops its speed down to the minimum for about 30 seconds. Then, all of a sudden, it kicks back into full speed. After working at full speed for 5 minutes, it goes back to very slow for about 30 seconds and then kicks back to high. Something is definitely wrong with either a sensor, programming of the AC control, or the fan. Has anyone else experienced something like this?

vdubpower

ive never used the auto setting but just keep it on AC and 60 on all my settings, and just adjust the fan as i need.

is it bad to keep it at one temp so low

ghstudio

Same problem in SW Florida and it seems to only drop speed twice, once after about a minute or so and then once again. After that, it works perfectly...I don't have the other problem with warm air blowing reported here which sounds like a freeze up. Let me know if you find the cause.....

I keep it in auto set to around 74 (2011 e350 BT)

Pntblnk

Same thing happened to me a couple months ago headed home from SanDiego. Drivers side AC started blowing hot air and ended up shutting all drivers side vents off and running the passenger side at 60 aimed at my side. It stayed that way for ~1 hour until I got home and then started working perfectly the next morning and I haven't had a problem since. I was probably running 80-85 with afternoon sun on drivers side. Odd that you had similar speed.

ghstudio

I checked with my dealer today and it is "normal" for the 350 to drop the speed of the A/C fan as it manages the electrical load in the car...and apparently it is more noticeable in the Diesel cars. It can happen more than once, although the most noticeable drop is the first one.

avisys

My very experienced, and nearly infallible, BS Detector is going "zing . . . zing . . . zing . . . "

mnje350

In SE North Carolina, hot and humid mid May till Sept. I leave it on auto at 68 degrees. Never had a problem. But, my trips are rarely longer than a couple of hours. I'd have the dealer check it out.

ghstudio

mine too actually....but I don't have the hot air coming out issue. This is just the maximum cool cuts out after about 20 seconds for just maybe a second and then it comes back on full.....and perhaps a couple of minutes later it does another "cycle" but doesn't slow quite as much for that second. I suspect a sensor but for now, I'll live with the dealer's answer.

Drgolf131

That is odd ... But you seemed to have exactly the same conditions and the same speed range. I suspect that there was an interaction effect between the speed, outside temperature and the time at speed.

Tynika Claxton

Did you ever find the answers to this Ac issue? I am having this problem with my 2011 gl450?

marythomus

Maybe the fragrance isn't strong enough? I also had this problem a while ago, and I thought that the air-balance was broken. And then I tried some new perfumes and everything worked just fine. I'm buying mines from Decantstore, you can visit the site here if you want. The Mercedes air freshener may not be working because it is low and needs a refill, clogged filter, or a climate control error. If your Mercedes air freshener is not working you will want to check the air freshener levels. Try it and then see what's happening.

kajtek1

Old topic and when it started, I did not own W212 yet, but digitally -controlled AC systems are installed on MB sedans since 1995 and all of them have the same principals, when knobs and displays can be different.
Here is the best site for help that I know. https://www.mercedesmedic.com/ac-air...le-codes-list/
Start with sensor calibration test. On most of modern cars you will need a scanner as MB deleted on dash-reading, but get up early in the morning before sun will affect car temperatures and read all the AC-related values without starting the engine.
Post them here if you want more forum help with interpretation.