mishar

16 bar is working pressure. With 5 bar it won't be able to lift the car from bump stoppers. So it is right in the middle, indicating that compressor rebuild may be successful fix.

haggisuk

You cannot guess at the compressors health by simply looking at measuring blocks.

In order to test the compressor you need to run an accumulator charge test as mentioned in the following thread

Once you start the test it will start the compressor charging the accumulator (air tank) but it will time out after a short time, you must repeat the test three or four times to get up to 16 bar, if you find that it won't go past say 12 bar don't keep re running the test as you will over heat the compressor.

http://forums.ross-tech.com/showthread.php?1996-Level-Control-Bleeding-Charging&highlight=Charging+bleeding

jeffkruse

First of all thanks everyone for all your help. I ran this test only once and here are the results. Any suggestions?
- Charging -

[Select]
[34-Level Control]

[Login-11]
[08367]
[Do it!]

[Basic Settings-04]
Enter:
Group [023] = to Charge Pressure Accumulator Field 4 = 14.97
Group [024] = to Charge Front Axle Field 4 = 8.14 bar
Group [025] = to Charge Rear Axle Field 4 = 6.18 bar

Field-[4] will display the current pressure
Note: System will time out after 60 seconds, the procedure maybe repeated as necessary to achieve the desired system pressure.

haggisuk

I would say then with confidence the piston ring is working just fine

richard-tx

Then the noise is likely an issue with the mounting.

jeffkruse

I might be missing an issue here, but I have never had a noise. Just the DTC Code 01772. Just trying to get rid of it. Thanks