E-Class (W211) 2003-2009

Need Air Conditioning Help

Thread Tools
 
Search this Thread
 
Rate Thread
 
Old 05-18-2023, 05:42 PM
  #1  
Newbie
Thread Starter
 
ethan214's Avatar
 
Join Date: Oct 2021
Location: New England
Posts: 14
Received 1 Like on 1 Post
2006 Mercedes e500 4MATIC, 2002 E320 4MATIC Wagon
Need Air Conditioning Help

The AC on my 2006 Mercedes E500 4MATIC never worked under my ownership until about a few months ago. I was able to get it running after replacing a sensor and recharging the refrigerant. I never used it though until just a few weeks ago when it started getting warmer outside. It worked great for the first couple weeks until I noticed the rear AC vents were blowing very hot air. The front still blew cold. The next day I noticed the front ac started blowing a bit warmer, but I could tell it was still working. The very next day my AC was completely dead and wasn't blowing cool at all anymore. On that day, I replaced the heater control valve at the firewall to hopefully solve the rear blowing hot air issue. It doesn't blow super hot air back there anymore, but my AC doesn't work at all so its not cold. My refrigerant level is still exactly the same as it was the day I filled it a few months ago. No leaks. I'm not sure what would cause my AC to stop working like that. Could it be related to the heater valve issue? I used my scanner to check for codes and I had an error code for the temp sensor in the dome light. I replaced that and I now have a correct temp reading, but my AC still doesn't work. The only fault code I have in all of my cars modules is for a sensor in the driver seat, which I'm sure will not affect my air conditioning lol. The scanner I am using is the iCarsoft CR Max. It's a cheap one but its more than enough for what I need. Any help would be appreciated, thank you!
Old 05-18-2023, 08:49 PM
  #2  
MBWorld Fanatic!
 
juanmor40's Avatar
 
Join Date: May 2021
Location: Tampa, FL
Posts: 2,023
Received 1,631 Likes on 1,020 Posts
2008 E350 (W211 @170K), 2012 ML350 (W166 @119K), 2014 E350 Sport (W212 @96K), 2015 ML350 (W166 @92K)
If the refrigerant is complete, you can set it to LO on both sides and it should work.

When on LO only pressure sensor (check for refrigerant) and the evaporator temperature sensor should control the compressor (prevent freezing in the evap)

does the icarsoft scanner shows pressure and evaporator temperature live?
Old 05-18-2023, 09:51 PM
  #3  
Newbie
Thread Starter
 
ethan214's Avatar
 
Join Date: Oct 2021
Location: New England
Posts: 14
Received 1 Like on 1 Post
2006 Mercedes e500 4MATIC, 2002 E320 4MATIC Wagon
Originally Posted by juanmor40
If the refrigerant is complete, you can set it to LO on both sides and it should work.

When on LO only pressure sensor (check for refrigerant) and the evaporator temperature sensor should control the compressor (prevent freezing in the evap)

does the icarsoft scanner shows pressure and evaporator temperature live?
Yes, the scanner shows me both of those stats, and lots more. I had the front and rear climate control set to low, the fan speed on max, with the AC button on, but I wasn't able to get any sort of cold air unfortunately. I had my AC refrigerant evacuated today to check the low pressure suction hose. It's original and I've heard they can collapse on these cars but it seemed fine to me. I'm unsure exactly how to test it, air flows freely when I blow through it. I don't want to start throwing parts at it just yet though.
Old 05-19-2023, 08:45 AM
  #4  
MBWorld Fanatic!
 
juanmor40's Avatar
 
Join Date: May 2021
Location: Tampa, FL
Posts: 2,023
Received 1,631 Likes on 1,020 Posts
2008 E350 (W211 @170K), 2012 ML350 (W166 @119K), 2014 E350 Sport (W212 @96K), 2015 ML350 (W166 @92K)
I would not have opened the AC cooling circuit/system w/o first diagnosing it. Opening the system is bound to create more problems, $$, than fix anything if you are not 100% certain about what you are aiming at.

Since you have evacuated and recharged the system more than once already, I assume you :
1 - have access to AC pressure gauges, correct?
2 - know the exact amount of refrigerant required for your car (read label under the hood)
3 - you weighted, or measured the amount of refrigerant, correct?

With the pressure gauges, and the scanner connected you should be able to pin-point the problem, but it requires several measurements and a bit of patience to avoid premature conclusions.

NOTE: since you have opened the circuit already multiple times, be prepared to replace the drier soon (only do so at the hopefully last time you opened again).
Old 05-19-2023, 02:56 PM
  #5  
Newbie
Thread Starter
 
ethan214's Avatar
 
Join Date: Oct 2021
Location: New England
Posts: 14
Received 1 Like on 1 Post
2006 Mercedes e500 4MATIC, 2002 E320 4MATIC Wagon
Originally Posted by juanmor40
I would not have opened the AC cooling circuit/system w/o first diagnosing it. Opening the system is bound to create more problems, $$, than fix anything if you are not 100% certain about what you are aiming at.

Since you have evacuated and recharged the system more than once already, I assume you :
1 - have access to AC pressure gauges, correct?
2 - know the exact amount of refrigerant required for your car (read label under the hood)
3 - you weighted, or measured the amount of refrigerant, correct?

With the pressure gauges, and the scanner connected you should be able to pin-point the problem, but it requires several measurements and a bit of patience to avoid premature conclusions.

NOTE: since you have opened the circuit already multiple times, be prepared to replace the drier soon (only do so at the hopefully last time you opened again).
Yes, I have a cheap manifold gauge from Harbor Freight. I used my scanner to check all sensors related to the AC system. It appears that the AC should be working based on the numbers I'm seeing but my car was blowing warm air. I spent a few hours yesterday troubleshooting but I can't seem to find the issue. I have no fault codes related to AC and my pressures were good. Theoretically everything should have worked but it didn't. So far I've heard it could be the compressor control valve, the low pressure suction hose that runs from the compressor up to the hard metal line near the coolant tank may have internally collapsed, or it might be the expansion valve. I feel as if it must something physically broken like one of those three since it appears like it should work based on the numbers.

I really appreciate your response, any bit of info really helps. Thank you!!
Old 05-19-2023, 03:10 PM
  #6  
MBWorld Fanatic!
 
juanmor40's Avatar
 
Join Date: May 2021
Location: Tampa, FL
Posts: 2,023
Received 1,631 Likes on 1,020 Posts
2008 E350 (W211 @170K), 2012 ML350 (W166 @119K), 2014 E350 Sport (W212 @96K), 2015 ML350 (W166 @92K)
Forum members are willing to help you, but you need to post not only qualitative data, but quantitative data,

What you consider normal, means nothing since that is a relative term, and data must not be biased.

Could you please do the following:
0 - Report ambient temperature (to verify if data from AC gauges makes any sense)
1 - Connect the AC pressure gauges with the car OFF, better if it is cold
2 - Connect the scanner, and from the AC live data monitor values for
Refrigerant Pressure
Refrigerant Temperature (I think 2006 has both sensors)
Commanding value for the compressor, Torque, Amperage, whatever the scanner calls it.
3 - Report pressure on the gauges, Low and High. Hopefully the same
4 - Report the values in the scanner
5 - Start the car, ON, no AC yet wait until it reaches normal temperature if not already there
6 - Turn AC ON, Maximum Fan Speed , @1500 RPM, and LO setting on both vents, and if the rear are adjustable those as well.
7 - Report data from AC gauges (LO and HI), and scanner
if you are able to touch the suction hose near the compressor (the thicker one), it should be a lot colder than ambient temperature, is it ?
anything abnormal on the gauges, like fluctuating pressures
8 - Turn the car OFF, and notice the AC pressure gauges
HI must lower toward original pressure
LO must go higher toward original pressure
Measure how long it takes to go towards original pressures, is it 5 min, or 30+ min?
You can make a table, and post the table. Let me show one https://mbworld.org/forums/e-class-w...ml#post8600850
Hopefully, we can make sense of the data and suggest the next step

NOTE: you forgot to answer the question regarding the amount of refrigerant to used to refill/recharge, and how you did it.

Last edited by juanmor40; 05-19-2023 at 03:25 PM.
Old 05-19-2023, 03:50 PM
  #7  
Newbie
Thread Starter
 
ethan214's Avatar
 
Join Date: Oct 2021
Location: New England
Posts: 14
Received 1 Like on 1 Post
2006 Mercedes e500 4MATIC, 2002 E320 4MATIC Wagon
Originally Posted by juanmor40
Forum members are willing to help you, but you need to post not only qualitative data, but quantitative data,

What you consider normal, means nothing since that is a relative term, and data must not be biased.

Could you please do the following:
0 - Report ambient temperature (to verify if data from AC gauges makes any sense)
1 - Connect the AC pressure gauges with the car OFF, better if it is cold
2 - Connect the scanner, and from the AC live data monitor values for
Refrigerant Pressure
Refrigerant Temperature (I think 2006 has both sensors)
Commanding value for the compressor, Torque, Amperage, whatever the scanner calls it.
3 - Report pressure on the gauges, Low and High. Hopefully the same
4 - Report the values in the scanner
5 - Start the car, ON, no AC yet wait until it reaches normal temperature if not already there
6 - Turn AC ON, Maximum Fan Speed , @1500 RPM, and LO setting on both vents, and if the rear are adjustable those as well.
7 - Report data from AC gauges (LO and HI), and scanner
if you are able to touch the suction hose near the compressor (the thicker one), it should be a lot colder than ambient temperature, is it ?
anything abnormal on the gauges, like fluctuating pressures
8 - Turn the car OFF, and notice the AC pressure gauges
HI must lower toward original pressure
LO must go higher toward original pressure
Measure how long it takes to go towards original pressures, is it 5 min, or 30+ min?
You can make a table, and post the table. Let me show one https://mbworld.org/forums/e-class-w...ml#post8600850
Hopefully, we can make sense of the data and suggest the next step

NOTE: you forgot to answer the question regarding the amount of refrigerant to used to refill/recharge, and how you did it.
I'm sorry, yes I missed the question. When I refilled the AC back in December, I used just a cheap AC hose that connects just to the low side and three 12oz cans of r134a. I made sure to get the cans without any sealant or "Stop Leak" in it. I started from 0 so I filled it to about 20psi, cleared the low pressure code in the AC control module, turned on the AC, and once I saw the pressure drop is when I started filling it. I believe the correct number is 34oz of R134a.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 


You have already rated this thread Rating: Thread Rating: 0 votes,  average.

Quick Reply: Need Air Conditioning Help



All times are GMT -4. The time now is 10:12 PM.