solved

[wally5.0]

Solved thanks

[philly42]

I'll see if there's a diagnostic procedure for that code.

There could be a leak with the vacuum lines that control the exhaust wastegate. (small diameter hoses going from the vacuum pump and tanks)

Leaks in the crankcase ventilation system....specifically the hoses going from the intake manifold to check-valve.

And obviously leaks in charged air intake pipes.

[philly42]

Originally Posted by wally5.0

I logged with a fancy Matco scanner and it sees and holds 16psi for short time. So, I know there isn't a boost leak. It is commanding the wastegates to open for some reason.

My brother just installed an upgraded intercooler on his Z4. With the scanner we pulled values from Actual Pressure and Target Pressure to determine if there was a boost leak.

Maybe we could narrow down the problem by comparing wastegate and target pressure values. This might show that your wastegate is opening too much or not adjusting well enough to keep the proper amount of boost.

[m5james]

Replacing most of the upper vacuum lines is simple but the ones going to the vaccum solenoids are harder to reach. I had reduced power warnings for almost a year, to the point where I could tip in the throttle and feel it before I got the warning light, ends up the hard vacuum line running from the engine ALL the way to the trunk had cracked. I just disconnected the line from the T that runs from the vacuum pump over to the fender where it converts from a soft line to a hardline...problem went away.

I'm at work and using my phone but feel free to search my threads, I'm kind of a pic whore because I like visuals and figure others might as well :-)

[philly42]

Did you only smoke the system from the intake? If so this may not show a leaking vacuum line for wastegate operation. If you want to smoke this part of the system it would be best to insert where the #6 hose connects to the #7.
To complicate things further...if you smoke that system, you may need to trigger the pressure converters #2 to see if hose #8 is leaking. This may be doable with the engine off, ignition on and trigger the component by calling up the DME ecu.

IMO, I think this is too much trouble and suggest just replacing those hoses. Like M5james mentioned, the lower hoses are difficult to access.

[philly42]

My bad...here it is.

I'm using ISTA / Rheingold for scanning. (rheingoldusa.com) it allows you to navigate all the computers in the car, read values on the fly and trigger components of an ecu. for example I recently replaced the air suspension and went into the respective ECU to fill and vent the air springs. Also got readings from the level sensor in mm to monitor any changes in height.

[m5james]

Reaching but I'm wondering if this might be related to the recall we have for our low pressure/intank fuel pumps.