Rafichicago

Hello forum members !
So a while back I have purchased a 2009 AMG wagon. Car has been great so far, I have been using it as a weekend car here in Chicago area. I’ve tried to find some info on my problem but haven’t gotten much luck so I thought that I will start a new thread, that maybe would help someone in the future. My problem is that the a/c would work while driving. When I would stop the car and engine sits at idle, air conditioning will shut off after short while and it wouldn’t blow more cold air until I would resume driving again. Also on occasion, heating wouldn’t blow hot air either, in order for it to work I would have to turn climate control unit completely off than turn it back on. When I do this it will blow warm air again. If any of the knowledgeable forum members would chime in I would really appreciate it. I am fairly handy and can work on the car to some extent, but with a/c it’s not exactly familiar. I have the heater valve ( the one that sits by the windshield, but haven’t got to replacing it just yet. Sorry for any and all mistakes, since I am not a native speaker. Good day to everyone!

Rafichicago

So nobody has any clue what that might be ? This can’t be so complicated 😉

hachiroku

mine does this at times also. sometimes the A/C comes on super cold within 2 seconds of engine start....other times it'll take 5 minutes. i've had my A/C inspected and all check out ok. generally for me this only occurs when its real hot outside and is random.

Rafichicago

My ac does it every time I stop let’s say at the traffic lights or just get stuck in a traffic.

Hulk

You guys need to check your expansion valves and evaporator
unfortunately you need to remove the whole dash to check those however if you need to top off the ac here and there more likely than not
look at my thread, it’s not easy

Rafichicago

There’s refrigerant in the system. It doesn’t have a leak. What it does do it stops cooling once engin is idling.

Hulk

Then it’s very well possible that it’s the expansion valve or if you are lucky the the refrigeration regulator but that works together with the expansion valve

Forrest Gump 9

Did you recently fill the Freon? Im 90% sure that you have too much Freon in your system. The easy fix is to let off some of the pressure on the high pressure side. If you have the ac gauge hooked them up and see what happens when the system is on.

Rafichicago

Thanks for replying. My wife is working at Mercedes dealer. Tech checked it and it seems to be the right amount of refrigerant in the system. For some reason he said that compressor should be replaced but I find this odd since it is working properly when driving. Weird... I don’t have problem putting new one in. I just don’t want to throw random parts on the car without fully diagnosing the issue.