Please help, when I turn on the ac on my 98 E300turbodieasel I get heat(very hot) from left side and center vents and cold ac from the right vents.

The left has always been hotter than the right even when the heat only is on but I could live with that. The AC however is too hot even though the other side is cool. It does this almost all the time.
Is there some sensor that I should be looking at?

Appreciate some clues, thatnks.
Acerejo

http://www.continentalimports.com/ser_ic40142.html

You will find the secrets to testing all of the functions of the system as well as scanning for fault codes if you read this article and follow its procedures. Good luck!

__________________
Marty D.

2013 C300 4Matic
1984 BMW 733i
2013 Lincoln MKz

Almost always low on refrigerant! That is the most common cause.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Thanks M. B. Doc,
If it is low on freon why is it nice and cold on the right side?

During the heat season the left side is always hotter than the right, could there be something wrong with the inside temp sensor?

Thanks again,
Acerejo

The expansion valve "sprays" the R134a into the passenger's side of the evaporator first!

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Thanks M B doc, this makes sense because it's been harder to keep up cooling on hot days in the last couple of years. I'll recharge it tonight and keep you posted.

Appreciate it

Acerejo

Marty,
Thanks for the link, I will check it out and keep it for future reference.
Acerejo

Checked the refrigerant with low side gage and it reads 45 lb at normal operating temp. According to the gage there is sufficient charge on system so I did not add any.
Coincidentally the check engine electronics light came on. Is it possible that some sensor could be bad or the entire climate controll panel?
I will get the codes read tomorrow and look for more clues.

apreciate any additional help before being in the mercy of the local benz dealer.

Thanks a cerejo

I have this problem also. I posted a write up a while ago with my data from the referenced web site. In my case the problem lies with either the electronic controller or the electrically actuated heater flow control valves. I am still struggling with this, but have found that if I put the system in "defrost" mode for a few seconds and then turn "defrost" mode off, the driver's side cools off just like the passenger side. This "fix" lasts for a few seconds to half an hour. When the system flips back to being screwy I just punch the defrost button again, wait until the system starts to respond, and then push it again. Sometimes it takes a few tries, but it will go back to cooling.

In my "test data" it was apparent the heater valve was being repositioned by either a failed actuator, or because it was getting a bum message from the computer gizmo on the dash. I suspect the dash control module, but will live with the quirks before I open my wallet and drop another lump of cash into this vehicle. Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

Thanks Jim,
I will try that trick in the morning.

Good luck, here is the thread I was talking about: W210 Air Conditioning System Fault Codes

Jim

__________________
Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)

Thanks M. B. Doc, you were right about the low refrigerant being the cause for hot left and cold right.

I decide to recharge even though the gage showed sufficient charge (blue area), now both sides cool very nicely. I guess the gage that comes with the interdynamics charge kit is not that acurate. After adding a can I get the same gage reading but cooling is back.

I do have a set of manifold gages but I don't know what the values should be so I didn't even hook them up.

I still have the check engine and check engine electronics light on, a friend of mine scanned it and it came up with 180 code fuel cooler. He reset it but it came back a short time later.
I am not sure how accurate his scanner is but I don't think the car has a fuel cooler.
The car is running fine otherwise, I'll probably have to get the codes scanned by repair facility to pinpoint it.

Acerejo

P0 180 means that the FUEL temp sensor (front of injection pump) 000-078-44-49 & o-ring isn't functioning properly. OF course the wiring connector at that plug could cause that problem!

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

M.B. Doc.
Thanks again, ironically the light didn't come on this afternoon, its slightly cooler out than the last couple of days, maybe that's why.

I will check the connector on the sensor though for loose connection and or sensor.

I appreciate your help again.

Acerejo

The correct fix for this car would be to replace the reciever/dryer and the hose running from it to the expansion valve. This is a very common problem. That I have fixed. The temp fix is to ad more freon and over charge the system which is dangerous. The problem will be back again. Usually on a hot day when you need the A/C the most. fix it right the first time! Good luck
Tech1