air conditioning
Thread Starter
Member
Joined: Sep 2005
Posts: 177
Likes: 0
From: Princeton NJ
2015 E350 4matic Sport and 2011 C300 4matic sport
air conditioning
On a long trip this past weekend, in 90+ degree heat, my AC would come on perfectly, blast cold air, slowlycalm down to the desired temperature and eventually quit blowing cool air. I could not adjust it after that except for the fan, but no adjustment to the temperature, we roasted. Wthen we would stop at a rest stop on the PA turnpike, get back in the car, and the AC would start blasting air and go through the whole thing again...Happened at least three times.
Any idea what is wrong or how to fix it? Clearly when you get in the car and start it up, it works fine and takes a while to cool off and stop working...
Help...
Any idea what is wrong or how to fix it? Clearly when you get in the car and start it up, it works fine and takes a while to cool off and stop working...
Help...
MBWorld Fanatic!
Joined: Mar 2006
Posts: 3,254
Likes: 15
From: Louisiana
03 E500 and Corvette
On a long trip this past weekend, in 90+ degree heat, my AC would come on perfectly, blast cold air, slowlycalm down to the desired temperature and eventually quit blowing cool air. I could not adjust it after that except for the fan, but no adjustment to the temperature, we roasted. Wthen we would stop at a rest stop on the PA turnpike, get back in the car, and the AC would start blasting air and go through the whole thing again...Happened at least three times.
Any idea what is wrong or how to fix it? Clearly when you get in the car and start it up, it works fine and takes a while to cool off and stop working...
Help...
Any idea what is wrong or how to fix it? Clearly when you get in the car and start it up, it works fine and takes a while to cool off and stop working...
Help...
MBWorld Fanatic!
Joined: Mar 2006
Posts: 3,254
Likes: 15
From: Louisiana
03 E500 and Corvette
I normally check mine with doors open, AC MAX cold temp set on 60 and the high side pressure is about 230-260 PSI on a 90 degree day.
But daily temps will vary the pressure. I put freon in my mom's car on a 65 degree day and the high side pressure was only 150. SO temps make it change a lot.
Use a refrigerant book graph to determine the actual recommended pressue for the temperature when you check it. My guess is yours is low and the expansion valve is closing to protect the compressor.
Thread Starter
Member
Joined: Sep 2005
Posts: 177
Likes: 0
From: Princeton NJ
2015 E350 4matic Sport and 2011 C300 4matic sport
Thanks, ever since I got back the AC has worked perfectly even on 100 degree days like we had last week in New Jersey. But I have not gone on any long trips...
MBWorld Fanatic!
Joined: Mar 2006
Posts: 3,254
Likes: 15
From: Louisiana
03 E500 and Corvette
