AC problem
Thread Starter
Newbie
Joined: Jul 2010
Posts: 10
Likes: 0
W210 270 CDI
AC problem
Its hitting 40+ C here so the intermittent issue with the AC is a major problem. I have gone thru the differernt forums and run all sort of diagnostic tests for the AAC without luck.
All sensor values OK when the AC is running normally. No error codes are given but the AC seems to have a mind of its own and will cycle on & off randomly. Let me try to explain the scenario and maybe some of the experts can guide me in the right direction
1. Switch on the AC in the morning and no cool air from the vents. Sensor#7 hovers around 7-9 range
2. Switch off/on the AAC or toggle between EC On/off few times and compressor will engage. Sensor#7 goes up to 15-18 range
3. After sometime (could be 5 mins or 5 hrs) compressor is again disengaged. I can see the Sensor 7 going down to 7-9 range.
4. switching off/on sometimes brings the AC right back other times air flow is completely shut off
5. problem is more prominent in the city driving than on the motorway
6. first suspecting the clutch but now the indie says the gap is fine
All sensor values OK when the AC is running normally. No error codes are given but the AC seems to have a mind of its own and will cycle on & off randomly. Let me try to explain the scenario and maybe some of the experts can guide me in the right direction
1. Switch on the AC in the morning and no cool air from the vents. Sensor#7 hovers around 7-9 range
2. Switch off/on the AAC or toggle between EC On/off few times and compressor will engage. Sensor#7 goes up to 15-18 range
3. After sometime (could be 5 mins or 5 hrs) compressor is again disengaged. I can see the Sensor 7 going down to 7-9 range.
4. switching off/on sometimes brings the AC right back other times air flow is completely shut off
5. problem is more prominent in the city driving than on the motorway
6. first suspecting the clutch but now the indie says the gap is fine
Super Member
Joined: Jun 2006
Posts: 525
Likes: 0
From: the Netherlands
'01 W210 E320 CDI
When you say the compressor disengages on it's own, does the EC light stay off?! If so it looks like the clutch...
I've just had my A/C system recharged today and checked for leaks using UV-dye at an indie airconditioning shop, but the EC light would still not come off thus not engaging the compressor. They advised me to goto a dealer and have them reset any errors in the Climate Control system. The dealer was extremely helpful, a reset with stardiag indeed solved it and they only charged me €34,-
I've just had my A/C system recharged today and checked for leaks using UV-dye at an indie airconditioning shop, but the EC light would still not come off thus not engaging the compressor. They advised me to goto a dealer and have them reset any errors in the Climate Control system. The dealer was extremely helpful, a reset with stardiag indeed solved it and they only charged me €34,-
Last edited by Lancelot; May 4, 2011 at 11:47 AM.
Thread Starter
Newbie
Joined: Jul 2010
Posts: 10
Likes: 0
W210 270 CDI
When you say the compressor disengages on it's own, does the EC light stay off?! If so it looks like the clutch...
I've just had my A/C system recharged today and checked for leaks using UV-dye at an indie airconditioning shop, but the EC light would still not come off thus not engaging the compressor. They advised me to goto a dealer and have them reset any errors in the Climate Control system. The dealer was extremely helpful, a reset with stardiag indeed solved it and they only charged me €34,-
I've just had my A/C system recharged today and checked for leaks using UV-dye at an indie airconditioning shop, but the EC light would still not come off thus not engaging the compressor. They advised me to goto a dealer and have them reset any errors in the Climate Control system. The dealer was extremely helpful, a reset with stardiag indeed solved it and they only charged me €34,-
I will be heading to the stealer tomorrow and try to convince him to reset the system however i fear its gonna be $$$$ news.
Thread Starter
Newbie
Joined: Jul 2010
Posts: 10
Likes: 0
W210 270 CDI
Dear Lancelot Need your help here. Took the car in to the stealer. After spending 2 days diagnosing the problem they said both the compressor and regulator motor needed replacement. The total estimate around $2000. Not convinced i asked them to reset the AAC. They didn't know how and had never done it before. Any idea what entails a reset and can it be done via the control panel.
Just to update i have narrowed down the problem to the AAC panel. The reason compressor would work intermittently is when running in AUTO mode. If i run it manually AC is working perfectly. The blower problem is also only faced when running it on full speed. There seems to be aproblem with the regulator. Is there a fix or the entire unit needs replacement
Just to update i have narrowed down the problem to the AAC panel. The reason compressor would work intermittently is when running in AUTO mode. If i run it manually AC is working perfectly. The blower problem is also only faced when running it on full speed. There seems to be aproblem with the regulator. Is there a fix or the entire unit needs replacement
Thread Starter
Newbie
Joined: Jul 2010
Posts: 10
Likes: 0
W210 270 CDI
Dear Lancelot Need your help here. Took the car in to the stealer. After spending 2 days diagnosing the problem they said both the compressor and regulator motor needed replacement. The total estimate around $2000. Not convinced i asked them to reset the AAC. They didn't know how and had never done it before. Any idea what entails a reset and can it be done via the control panel.
Just to update i have narrowed down the problem to the AAC panel. The reason compressor would work intermittently is when running in AUTO mode. If i run it manually AC is working perfectly. The blower problem is also only faced when running it on full speed. There seems to be aproblem with the regulator. Is there a fix or the entire unit needs replacement
Just to update i have narrowed down the problem to the AAC panel. The reason compressor would work intermittently is when running in AUTO mode. If i run it manually AC is working perfectly. The blower problem is also only faced when running it on full speed. There seems to be aproblem with the regulator. Is there a fix or the entire unit needs replacement
Junior Member
Joined: Dec 2009
Posts: 18
Likes: 1
From: minnesota
1999 E320, 2000 ml430
look at sensor #5. Under normal operation it should read 35 to 40 degrees F (compressor running) , if it shows higher such as 140 degrees F it is faulty, this is the evaporator temperature sensor. sounds like the control unit is shutting off the compressor due to an implausible value.
MBWorld Fanatic!
Joined: Apr 2007
Posts: 6,171
Likes: 16
300E a couple 1994 w124wagon E320 Wagon/,1971MGB Track/Rally, MG Midget Autocross ,2000 E320 wagon.
If you have
the digital climate control run the a/c diagnostics and post the values and errors.
For future reference to clear errors just hit both auto buttons while in error reading mode and it will clear them.
For future reference to clear errors just hit both auto buttons while in error reading mode and it will clear them.
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Thread Starter
Newbie
Joined: Jul 2010
Posts: 10
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W210 270 CDI
sensor values when ac is blowing cold air.
1: 35
2: 41
3: 15
4: 15
5: 11
6: 65
7: 14-18
8: 45
sensor values when ac is NOT blowing cold air.
1:38
2:42
3:38
4:37
5:37
6:82
7:7-9
8:38
Again in city driving ac tends to cycle on & off more frequently than on the motorway.
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MBWorld Fanatic!
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300E a couple 1994 w124wagon E320 Wagon/,1971MGB Track/Rally, MG Midget Autocross ,2000 E320 wagon.
YOUR RIGHT
AND LEFT HEATER CORE ARE AT 59f
and evap temp at almost 52F that is functioning but barely.
If the ec button is not stuck on make sure the aux fan is spinning when operating the a/c and either add some r134a or have it checked and charged.
If in manual it works fine then it surely is not the compressor and if in auto the high fan is not active you can replace the regulator cheaply by following the diy over on the w210 section of www.benzworld.org in the diy stickies at the top of the page.
Don't spend 2 grand to replace a compressor that is spooling up but not operating as it should,fix what is the non functioning problem.
Or operate in manual mode until you do
and evap temp at almost 52F that is functioning but barely.
If the ec button is not stuck on make sure the aux fan is spinning when operating the a/c and either add some r134a or have it checked and charged.
If in manual it works fine then it surely is not the compressor and if in auto the high fan is not active you can replace the regulator cheaply by following the diy over on the w210 section of www.benzworld.org in the diy stickies at the top of the page.
Don't spend 2 grand to replace a compressor that is spooling up but not operating as it should,fix what is the non functioning problem.
Or operate in manual mode until you do
Junior Member
Joined: Dec 2009
Posts: 18
Likes: 1
From: minnesota
1999 E320, 2000 ml430
when the system is supposed to be working - is there voltage to the compressor clutch? maybe the clutch has an inter. open or short that the ACC is not flagging as a fault.
Thread Starter
Newbie
Joined: Jul 2010
Posts: 10
Likes: 0
W210 270 CDI
After spending a week
Checked for leaks and ref. levels. All looked ok. Indie is going to replace the blower motor since fan speed problem persists even after bypassing the regulator. How do u check the voltage to the compressor clutch?
Newbie
Joined: Sep 2012
Posts: 8
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w210 E280 2000
Did you find the answer to the aircon problem as i have a similar problem but failed
Did you find the solution to your problem as i have a simliar problem.
Its hitting 40+ C here so the intermittent issue with the AC is a major problem. I have gone thru the differernt forums and run all sort of diagnostic tests for the AAC without luck.
All sensor values OK when the AC is running normally. No error codes are given but the AC seems to have a mind of its own and will cycle on & off randomly. Let me try to explain the scenario and maybe some of the experts can guide me in the right direction
1. Switch on the AC in the morning and no cool air from the vents. Sensor#7 hovers around 7-9 range
2. Switch off/on the AAC or toggle between EC On/off few times and compressor will engage. Sensor#7 goes up to 15-18 range
3. After sometime (could be 5 mins or 5 hrs) compressor is again disengaged. I can see the Sensor 7 going down to 7-9 range.
4. switching off/on sometimes brings the AC right back other times air flow is completely shut off
5. problem is more prominent in the city driving than on the motorway
6. first suspecting the clutch but now the indie says the gap is fine
All sensor values OK when the AC is running normally. No error codes are given but the AC seems to have a mind of its own and will cycle on & off randomly. Let me try to explain the scenario and maybe some of the experts can guide me in the right direction
1. Switch on the AC in the morning and no cool air from the vents. Sensor#7 hovers around 7-9 range
2. Switch off/on the AAC or toggle between EC On/off few times and compressor will engage. Sensor#7 goes up to 15-18 range
3. After sometime (could be 5 mins or 5 hrs) compressor is again disengaged. I can see the Sensor 7 going down to 7-9 range.
4. switching off/on sometimes brings the AC right back other times air flow is completely shut off
5. problem is more prominent in the city driving than on the motorway
6. first suspecting the clutch but now the indie says the gap is fine
Newbie
Joined: Sep 2012
Posts: 8
Likes: 0
w210 E280 2000
Intermittent climate control problem
I have a frustrating problem over 3 months.2000 e280.Readings in celcius(South Africa). Aircon works intermittently.Ec button light stays off. air con randomly blows warm air and if ec light is toggled on and off sometimes it may start blowing cold air.I have cleaned duovalve,changed evap sensor,changed in dash control module,pressure and refridgerant temp sensors and interior cabin sensor and done an evac and recharge.When it is cooling pressure on manual guage are fine on hi and low side.Compressor does engage.No fault codes thrown.Values 1-26// 2-36//3-11//4-10//5-08/6-86/7-16//8-60 . I compared values when it is not cooling-the crompressor is engaging(spinning on side and ec light remains on and values 1-27//2-26//3-25//4-25//5-24//6-84//7-06//8-31. If i now press the ec button twice to turn the ac on again it tends to cool again and the number 7 sensor goes up to 15.I am at my wits end on this!!! Please help as i am desparate.
Newbie
Joined: Sep 2012
Posts: 8
Likes: 0
w210 E280 2000
aircon works intermittently
@Ohlord No error is shown on the diagnostic system. The value given is E FF. Should i reset it anyway by pressing both the Auto buttons?
sensor values when ac is blowing cold air.
1: 35
2: 41
3: 15
4: 15
5: 11
6: 65
7: 14-18
8: 45
sensor values when ac is NOT blowing cold air.
1:38
2:42
3:38
4:37
5:37
6:82
7:7-9
8:38
Again in city driving ac tends to cycle on & off more frequently than on the motorway.
sensor values when ac is blowing cold air.
1: 35
2: 41
3: 15
4: 15
5: 11
6: 65
7: 14-18
8: 45
sensor values when ac is NOT blowing cold air.
1:38
2:42
3:38
4:37
5:37
6:82
7:7-9
8:38
Again in city driving ac tends to cycle on & off more frequently than on the motorway.
I have had an almost identical problem to yours and wish to know how you solved it.My last suspect is the aircon compressor but not sure.Any help out there.
Newbie
Joined: Jul 2008
Posts: 1
Likes: 0
'97 E320
Problem solved - EXPANSION VALVE !!!!
I have been chasing this same problem for more than a few years - today I finally fixed it by replacing the... (drum-roll, please)... EXPANSION VALVE.
(Freon and receiver drier were also replaced at the same time as the expansion valve. Previous replacement of freon and receiver/ dryer alone did not fix the problem.)
The symptoms were that the system would blow cold air for a few minutes, then stop working. It would continue to blow ambient temperature (generally warm or hot, I live in Phoenix AZ) air, but not cold air. The "EC" light did not come on. No codes. Turning off the AC, or the compressor only by pressing the "EC" button, for a few minutes, then turning the AC back on (or EC off) would result in a few more minutes of cold air, then back to blowing ambient (warm) air. Connecting a set of gauges showed that the system pressures were within the specified ranges during the few minutes of cold air. 34 psi low side, 240 psi high side. (Low spec is 1.5 - 2.0 bar, 22-29 psi, high spec is 11-17 bar, 160-245 psi) When it wasn't cooling both the low and high pressures oscillated about twice per second. The high side was in spec but oscillating between 180 and 190 psi. (lower than when cooling normally). The low side was oscillating between 31 and 36 psi, slightly above the upper spec limit.
During the past few years I have tried nearly all of the simpler "solutions" offered in this and other forums - none worked. (But thanks for the suggestions, nonetheless. I am certain that they were sincere.) These included: Replace temperature sensor ( the one in the cabin in front of the evaporator). Replace dash control unit (junk yard find). Replace freon and receiver/dryer.
(Freon and receiver drier were also replaced at the same time as the expansion valve. Previous replacement of freon and receiver/ dryer alone did not fix the problem.)
The symptoms were that the system would blow cold air for a few minutes, then stop working. It would continue to blow ambient temperature (generally warm or hot, I live in Phoenix AZ) air, but not cold air. The "EC" light did not come on. No codes. Turning off the AC, or the compressor only by pressing the "EC" button, for a few minutes, then turning the AC back on (or EC off) would result in a few more minutes of cold air, then back to blowing ambient (warm) air. Connecting a set of gauges showed that the system pressures were within the specified ranges during the few minutes of cold air. 34 psi low side, 240 psi high side. (Low spec is 1.5 - 2.0 bar, 22-29 psi, high spec is 11-17 bar, 160-245 psi) When it wasn't cooling both the low and high pressures oscillated about twice per second. The high side was in spec but oscillating between 180 and 190 psi. (lower than when cooling normally). The low side was oscillating between 31 and 36 psi, slightly above the upper spec limit.
During the past few years I have tried nearly all of the simpler "solutions" offered in this and other forums - none worked. (But thanks for the suggestions, nonetheless. I am certain that they were sincere.) These included: Replace temperature sensor ( the one in the cabin in front of the evaporator). Replace dash control unit (junk yard find). Replace freon and receiver/dryer.
