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My AC is acting a little funny, would like anyone's thoughts on what might be the culrpit here, since I've already tried the changeover valve. Details:
Car
w211 '07 E350
Dual zone climatronic in front, just regular vents in the rear on center console.
Does not have rest button, can't get to diagnostics info from this unit.
Outside temp 90+:
- Everything works perfectly. All vents blow the same cold air; auto increases fan speed when getting in the car and lowers as the car cools. All good.
Outside temp ~70:
- Rear vents randomly blow hot air. Seems to be very dependent on outside temp - never ever happens when it's 90+, but once it dips under 70 it always happens.
- Left dash vent slightly warmer than center vents.
Outside temp ~50:
- Center dash vents blow cold when on auto, even when turned to max heat. Switch to manual and all vents will blow warm air
- I wouldn't call it overly hot air, seems like it should be a little warmer.
New Changeover/Heater Control Valve
Research pointed to this. It was $40 so I went ahead and did it. I don't see any changes in behavior, this appears to have done nothing.
AC Pressure
Research also pointed to low AC pressure as a possible issue. Bought a recharge kit and used it to test the pressure a few times. It always seems to be exactly where it should be, so haven't added any freon.
HELP? Anyone have any ideas what might be going on here? I've only had the car a few months, so I haven't bought a scanner yet, I'd get some pretty good diagnostic data from it that would help?
I posted links and pictorial how to troubleshoot the system in this section.
You will need a scanner, but then taking readouts takes only seconds and you will have clear picture what troubles your system has without getting your hands dirty.
Definitive diagnose, have some pull fault codes using MB DAS (diagnostics). Three sensors regulate interior temperature one or more, or none may be malfunctioning …or something else may be causing your problem.
B10/4 part # 2118300272
N70b1 incorporated into OCP circuit board
B14 # 0075421318
Definitive diagnose, have some pull fault codes using MB DAS (diagnostics). Three sensors regulate interior temperature one or more, or none may be malfunctioning …or something else may be causing your problem.
B10/4 part # 2118300272
N70b1 incorporated into OCP circuit board
B14 # 0075421318
B14 is easy to test because the temp is displayed on the dash, and if its not in close agreement with Siri well then...
My AC is acting a little funny, would like anyone's thoughts on what might be the culrpit here, since I've already tried the changeover valve. Details:
Car
w211 '07 E350
Dual zone climatronic in front, just regular vents in the rear on center console.
Does not have rest button, can't get to diagnostics info from this unit.
Outside temp 90+:
- Everything works perfectly. All vents blow the same cold air; auto increases fan speed when getting in the car and lowers as the car cools. All good.
Outside temp ~70:
- Rear vents randomly blow hot air. Seems to be very dependent on outside temp - never ever happens when it's 90+, but once it dips under 70 it always happens.
- Left dash vent slightly warmer than center vents.
Outside temp ~50:
- Center dash vents blow cold when on auto, even when turned to max heat. Switch to manual and all vents will blow warm air
- I wouldn't call it overly hot air, seems like it should be a little warmer.
New Changeover/Heater Control Valve
Research pointed to this. It was $40 so I went ahead and did it. I don't see any changes in behavior, this appears to have done nothing.
AC Pressure
Research also pointed to low AC pressure as a possible issue. Bought a recharge kit and used it to test the pressure a few times. It always seems to be exactly where it should be, so haven't added any freon.
HELP? Anyone have any ideas what might be going on here? I've only had the car a few months, so I haven't bought a scanner yet, I'd get some pretty good diagnostic data from it that would help?
I also have a 07 E350. When I bought the car, AC run without problem. For pro active purpose, I also replaced the the change over valve. Anyway, I also notice the behavior exactly like the 3rd scenario stated above!! On auto heating setting, he central vents blow not-hot air, other blow hot air as supposed to!? I have icarsoft 980, had scanned many times without any code.... so I assumed it is normal?!!
I also have a 07 E350. When I bought the car, AC run without problem. For pro active purpose, I also replaced the the change over valve. Anyway, I also notice the behavior exactly like the 3rd scenario stated above!! On auto heating setting, he central vents blow not-hot air, other blow hot air as supposed to!? I have icarsoft 980, had scanned many times without any code.... so I assumed it is normal?!!
My scanner arrives tomorrow. I suspect that the colder air from the center vents is normal. But I am getting nothing but luke-warm air out of everything else no matter what I do. Hopefully I get a code or diagnostic data that points me in the right direction.
I don't drive my cars in cold weather much, so can't say much how heating works, but from my recollection W211 is first MB body that mix warm air into central vent.
All previous models had cold air only from the center.
That said, iCarsoft has flappers testing available, so that should help in troubleshooting.
10-30-2018, 09:53 AM
