AC is not working
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Newbie
Joined: Oct 2021
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R350
AC is not working
Hi all, two months ago I found that my AC is not sending cold air anymore. Got some refill of Refrigerant by shop and it works for two months. Now back to the same problem. I tried to scan the car and found AC was functioning well, at least no code at all. But saw something weird. The left footwell temp sensor showing single digit degree while the rest showing normal temp, around 28-29 degree. Need some advice - do u think it is the cause of not sending cold air becoz the car thought temp is low enough?
thanks in advance for your help!
thanks in advance for your help!
Out Of Control!!
Joined: Sep 2018
Posts: 14,692
Likes: 4,584
From: unbegrenzt
2017 GLE350 4MATIC
Sounds reasonable. Have an independent shop scan using XENTRY and check all parameters: temperatures and refrigerant pressure.
Have you 100% ruled out a refrigerant leak? I didn't see that in your post above.
Have you 100% ruled out a refrigerant leak? I didn't see that in your post above.
Member
Joined: Jul 2013
Posts: 167
Likes: 20
None
Hi all, two months ago I found that my AC is not sending cold air anymore. Got some refill of Refrigerant by shop and it works for two months. Now back to the same problem. I tried to scan the car and found AC was functioning well, at least no code at all. But saw something weird. The left footwell temp sensor showing single digit degree while the rest showing normal temp, around 28-29 degree. Need some advice - do u think it is the cause of not sending cold air becoz the car thought temp is low enough?
thanks in advance for your help!
thanks in advance for your help!
Weird problem.
Please keep us posted on this.
Although Autumn is upon us and you may not be using your AC much for a while.
MBWorld Fanatic!
Joined: Oct 2010
Posts: 5,142
Likes: 1,293
From: Southern US
2010 E550, 273 Engine: 2012 S550, 278 Engine
I had this issue with my 2010 E550 when out of the blue my A/C stopped giving cold air. Barely cooled air came out of vents.
First thought was the refrigerant had leaked out so i added some and it got worse. Also the fan in front of car started screaming at full speed.
This problem started with the system never serviced before.
After things got worse with adding refrigerant the logical thought was that perhaps the system is overcharged. I let some out, about 5 psi worth on low side gauge (pressure before adding), and the system started working and is still working fine after some years of this incidence.
It is very easy to test if the system is overcharged. Just let refrigerant out in a couple psi steps and monitor air temp out the vents. You need a pressure gauge on the low side to do this.
At the point air temp goes higher you know overcharge is not the issue and you can add refrigerant charge back to level where it was.
A shop working on the ststem evacuating it and then adding refrigerant back by MB instructions does not fix anything if MB charge is too high to start with, which was the case with my car.
First thought was the refrigerant had leaked out so i added some and it got worse. Also the fan in front of car started screaming at full speed.
This problem started with the system never serviced before.
After things got worse with adding refrigerant the logical thought was that perhaps the system is overcharged. I let some out, about 5 psi worth on low side gauge (pressure before adding), and the system started working and is still working fine after some years of this incidence.
It is very easy to test if the system is overcharged. Just let refrigerant out in a couple psi steps and monitor air temp out the vents. You need a pressure gauge on the low side to do this.
At the point air temp goes higher you know overcharge is not the issue and you can add refrigerant charge back to level where it was.
A shop working on the ststem evacuating it and then adding refrigerant back by MB instructions does not fix anything if MB charge is too high to start with, which was the case with my car.
