I recently purchased a 1998 E320 with a failed blower regulator. I replaced it myself, and topped off the A/C with R-134. When it gets hot out, and the A/C kicks in, the left vents blow air that is significantly warmer than the right. I have run a flap test, and the flaps seem to behave normally. I suspected a bad duo-valve, so I replaced it, but there has been no change. Interestingly, when I try to manually force air to the floor, there is always air to the center outlets, regardless of the manual settings. Durignthe flap test, several position close off this air completely. One post I read somewhere indicated that if the evaporator had been replaced with a newer, shorter version, that a baffle is required to block the unused space, and if ommitted, would cause the system to blow warm air out the left side.
1) Is is possible to gain any small amount of access to the evaporator space to determine if it is full length or not?
2) Any other ideas as to why it is doing this?
Help??
John

 

There was an old service information about this exact complaint for 210 chasis vehicles. The repair was replacement of the reciever(filter)-drier. Don't ask me why but it does fix it. I have repaired at least a half dozen cars with this exact complaint.

 

Do a search on mbworld.org or benzworld.org saw something about the baffle on one of the forums,also have you run the on board diagnostics to see if you have failed or faulty sensors?Might help to see if something else is wrong,also links to continentalmotors article I think about how to run the complete flap tests.
ohlord
"GOT CODES?"

 

Already ran flap test, and diagnostics. Came up clean.

 

Baffled?
Get the baffle....
ohlord
"GOT CODES?"

 

i agree with mbtechinfo- replace the receiver drier.

 

Reciever-Drier? Really? I will give it a shot, but will I have to make friends with an A/C mechanic first. I don't have an evac pump, and I suspect that the dealer wants a lot of $ for that procedure.

 

ac work at the dealer is unfortunately expensive. merecedes had a dtb out on the subject of the receiver / drier a few years ago.

 

I have the same issue on my 1998 E300TD

My codes look pretty good - the numbers work out... there are a couple of service codes, but they seem unrelated.

I cleaned my duo-valve - no luck. I even clamped off the lines feeding the heater cores just to make sure... still warm on driver's side.

One user on another forum found that charging his A/C to 17 (on code 7 during a/c diag) helped his. No luck with that either.


If I get this fixed up, I'll post about it!

Cheers!

 

Read my post on the other forum.Have you ran the ob a/c diagnostics or just plugged in an obd scanner?service codes?unrelated?What are you talking about?
ohlord