P0101 After Major Work, Can't Figure It Out

Howdy!
My 2006 Jetta TDI DSG has about 230k miles on it. In the past 1k miles I have replaced the camshaft, lifters, timing components, DMF, head gasket.

After the most recent service, which was the head gasket, I started seeing P0101 come up. At first I discovered the hose to the turbo to be loose, my mistake, the one from the air filter. Then I replaced the MAF sensor, and it still came up. I had a tuned out EGR, so I reflashed the non-tuned image thinking maybe it was an EGR conflict of sorts. P0101 is still coming up and I am not aware of any loose connections. When I had the head off, I cleaned the intake and EGR valve as best as I could and checked the turbo wheel for play, no play. It comes up after about 20 miles of driving in mixed conditions, light traffic and highway driving.

I am out of ideas.

I have a Vagcom so can run logs and such, can someone tell me what I would be looking for and which tests to run for this error?

Ross tech has a few more checks that you missed
I would log MAF actual vs specified to see what’s up.
Your certain the EGR has been tuned out?

http://wiki.ross-tech.com/wiki/index.php/16485/P0101/000257


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Will go through all of that and report back!
Thanks!

mextdi said:

Will go through all of that and report back!
Thanks!

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Any updates?


Did you see this: http://forums.tdiclub.com/showthread.php?t=361224

Just wanted to update you guys on this.

I believe the issue is now fixed. For the easy two second read, it was an issue with the valve cover gasket not seating right and leaking vacuum and oil.

If you want to know what the issue was, read on.

After major service to the head, camshaft, timing belt, etc, I decided to replace the valve cover gasket as well. It turns out that it was not sealing correctly on the corners where it is raised up due to the camshaft. A few days ago, after moving the car, I saw a big oil spot on the floor. Because my car has the tray underneath, it had pooled in there, for a long time and there was plenty of oil. I read about the leaks in the rear of the BRM engine and it seemed it is the valve cover that is usually the culprit.

I removed the valve cover, cleaned the rubber and the channels as best as I could, then added a dab of silicone in these troublesome areas, then reassembled. First thing I noticed when doing this is that the vacuum line going to the N75 when disconnected would have a LOT of suction. It didn't have that before... And I was getting the error when the intake pipe going into the turbo was loose... Well, there is a big pipe on top of the valve cover that goes straight to that area where the intake goes into the turbo. By loosing vacuum and leaking oil down the backside of the engine, it was probably causing this error to occur. It has been a few days and after cleaning the rear of the engine, only a few remaining drops have touched the floor, nothing major.

I believe the intermittent vacuum issues due to the valve cover not sealing correctly created the MAF malfunction. It is a good idea to double check where the intake pipe connects to the turbo and also to make sure that you are not losing oil and/or compression because not only do you get the MAF code, you also compromise the variable vane action on the turbo.

So far so good, if I do get the code back, I will tell you more!