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Discussion Starter #1
Several weeks ago I took my E320 to a shop to have an A/C problem fixed. They wanted over $600 just to diagnose it, and I said no thanks. They said I had a flap problem. At the time, the A/C was blowing cold air only out the right side. The left side blew ambient air. It wasn't warm enough outside to tell if the right side cold air was as cold as it should have been, but it was noticeably cooler than the left side.

I had a bad evaporator temp sensor which I had replaced. But that didn't fix the problem.

The temp today is in the mid 80s. Now, neither side blows cold air. I ran the flap test and found that #2 (right diverter flap) would not activate. Ironically, it was the right side that was blowing cold air before.

Here's the info from the self-diagnosis of the A/C with the engine off & cold:

01 - 118 F
02 - 85 F (within 1* of dash)
03 - 103 F
04 - 102 F
05 - 103 F
06 - 139
07 - 5 bar
08 - 89 F

I let it warm up and drove a couple minutes. The refrigerant pressure reached a high of 8 bar but settled around 6 bar. None of the heater core / evaporator core temps changed significantly. What should the refrigerant pressure be? 6-8 bar strikes me as being very low, especially considering that it sits at 5 bar when the engine is off. I could have sworn I saw it as high as 13 bar a month ago. Hopefully I don't have an evaporator leak! The EC button operates normally.

For what it's worth, I hear a hissing noise from the center vent area when the A/C compressor is turned on. Perhaps a vacuum leak for actuating the right diverter flap that failed? (Although I don't hear the noise when doing the flap test.)

Any thoughts would be greatly appreciated!

Blake
 

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Ok Lexrex, Ill be brutally honest with you, I personally don't have nearly the same knowledge of the A/C system as you do. But I do have almost the same damb problem with my A/C. The mechanic also told me that the cost of repair was going to be high. Anything you find would be great!
 

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Discussion Starter #3
Hope it turns out to be inexpensive in the end. Does anyone know what the refrigerant pressure (#7) is supposed to be in a working A/C?
 
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