2nd Gen Most liked posts in thread: R56 owner new to the site

Alrighty. Did a smoke test today and no leaks, so my issue has to 100% be the timing chain. I will go to Detroit Thursday or Friday and get Detroit Tuned to install their new timing chain for me. Will report back after this.
As an extra, I get tons of foam in my oil cap from what must be due to a combination of air getting in due to mis-timing and this bloddy Chicago cold(negatives today in March!) What does the board recommend for engine oil? Should I go lower than 5w due to the cold? I use LiquiMoly 5w-40 now.

 

and that is a big fat negative to the timing chain. The five hour drive at 3am to Detroit and then back in the evening did not fix my issues. Detroit Tuned was awesome but no luck clearing my P129E code. At least now I have a timing chain that will last awhile and not have to worry about it.
Driving back did bring up some interesting stats though:
The P129E only comes on when starting the car. If it is cleared I can drive hours without it popping up, but the next time I start the car there it is.
MAF reads 0.00 at idle and 0.03 at highway speeds
and coolant temperature is around 150-160F after hours of highway driving.
Tomorrow I will check the diverter valve but after that I'm at a loss. Shouldn't air be flowing through the MAF sensor even at idle?
And low coolant temperature is nice, but does it indicate an issue? The thermostat was replaced 6 months ago.

 

The wastegate!!! That might explain everything. Getting 17mpg in city driving but 33mpg on the highway. The air sensors being off and everything else. Now to test the bloody thing. I was I had the $1,000 back from the un-needed timing chain to possibly pay for a new turbo as I'm pretty sure the wastegate itself cannot be fixed or replaced. But first to make sure it is the problem.

 

The DT mechanic is the one that came up with the wastegate idea. When he told me I thought he meant the diverter valve and couldn't understand how that could be the issue. But now that I've researched what the wastegate really is I can see it being stuck in the open position causing the issues I am having, though I do not see how it would effect coolant temperature. But everything else could be explained by it.

 

and after more driving today back down to 18mpg, so no change from replacing the timing chain.
My 160F to your 220F coolant difference is quite large. I sure hope it isn't leaking into the engine block or else this car will turn out to be my worst vehicle purchase ever.
Boost feels alright. I don't know how to measure it.
I got these stats with key on, engine off just to test the sensors:

EngineCoolantTemperature-70F
IntakeAirTemperature-59F Shouldn't these two be close?

Baro-14.4psi
MAP-12.2psi Shouldn't this and Baro be the same with the engine off?
MAF-0.0lb/sec and 0.03lb/sec moving. Seems way too low but no idea why air wouldn't be moving out of the airbox towards the turbo.

FuelRailPressure-71.1

 

You guys won't believe this. I pulled the diverter valve off a few minutes ago and it looked in brand new condition. Strange for a car with 78,000 miles. The bolts though were covered in what looked like locktite dust, which I don't think the factory does. When I went to clean and inspect where the diverter valve goes I found a piece of rubber about an inch long just hanging out in there. Obviously broken from somewhere and it looks slighty familiar. Took it out, cleaned, and replaced the valve.
Started the car up and immediately everything was perfect. No P129E code, O2 sensor to.455v from .80v. Who knew the diverter valve could cause so many issues?
Now to take a road trip and see how she does.

 

and I'm back. Made it over two weeks but today all my symptoms came back. P129E code, rough idle, oxygen sensors back to old readings. Plus the addition of the car dying sometimes when starting from a stop, like I don't give it enough gas. Went straight to the diverter valve and was expecting another piece of rubber in there, as before, but nothing. So now I am stumped. It must be another piece of the rubber shown above but I have no idea where it might be. Does anyone know the airflow through the diverter valve or where I should look?