AC not getting cold

[Andythegriff]

Hi,
The AC on my 2011 GL350 Blue Efficiency doesn't get cold. Everything appears to be working fine, have checked the air temp sensors etc on my icarsoft and nothing appears to be wrong. Its never managed to chill the incoming air at all since i have had it and running the system for 15 mins + makes no difference to the air supply temps in the car.

The local garage has re-gassed the system. They removed 750g of gas and replaced it with 950g. Vacuum test etc all past ok with no leakage. The icarsoft shows a system pressure of 6.5 bar but i don't know where that is (pre or post evaporator etc). Checking the function on the icarsoft also shows that the duty on the compressor is also being at least requested of correctly...100% on full cold and if i switch the AC off it slowly drops down as per the control functionality.

Any thoughts or ideas on what it could be or any ideas on how to check things physically/manually to see if things are working before i open up another can of worms with the local mechanic...i saw a vid on you tube about potentially collapsed compressor pipes but wasn't sure if that was applicable to these vehicles?.

Thanks very much for any help
Andy

 

[D2028]

Vacuum test isn’t as good or as accurate as a pressure test, pressure test with dye more likely to rule out leakages

 

[DSM10000]

Does the cooling fan or fans run when you turn the AC on?

 

[Trickythemerc]

Have you checked for a dirty/blocked pollen filter ?

 

[alabbasi]

Sometimes you have to reset the system. I just had to do this to a friends W220 S500. Shop told him he needed a new compressor at $1500 because it was not engaging. I did the reset on the climate control panel and added 1lbs of R134a, then sent him on his way.

Why is it always the compressor?

 

[badgx]

^^^X2

Test run without cabin filter to rule it out.

 

[Merc59]

Vacuum test isn’t as good or as accurate as a pressure test, pressure test with dye more likely to rule out leakages

Agreed mine held vacuum for 45mins but lost charge overnight, when system was pressurised with air and finally nitrogen leak on evaporator was discovered

 

[Montreal300]

Actual pressure difference between low and high sides is more important than just the high pressure side measurement.