crapi77

Good Morning Campers! I just bought a 2006 B7 2.0 six-speed Quattro. Anyway, I had what seemed like the turbo going away as I went over the Donner Summit going from CA to NV. The car lost power and was surging at idle. I also had to start it multiple times after it died trying to get the car moving. It seems after I "revved" the engine to 3K for 30-60 secs, the idle settled down and I was able to drive it again, although it had no power. It also threw the P0299 turbo under-boost code. Thinking it likely the diverter valve from what I read, I got one from Audi in Reno and replaced it. I cleared the code and the car was acting like it did going over the summit. Revved it again to 3K and the idle settled and the car was driveable. It is better, thinking it is getting some boost, but not as it should be or as it was prior to having issues. Any thoughts would be appreciated. Thanks all!!

WeeJimmy

Hate to state the usual but it sounds like a possible boost leak on one of the hoses between the turbo and the throttle body.
The P0299 code is usually due to either a torn diaphragm on the older revision DVs or because a GFB DV+ is fitted.

The fact you've had no replies so far concerns me, I signed up hoping some turbo yoda type genius could help me with my turbo issues (B7 06 2.0T 6MT special edition). Not looking good for either of us buddy.

Definitely check all your big hoses, they don't seal too well and if you're getting a code even after replacing the DV chances are it's leaking boost, the other symptoms you describe also point to that, if you blow a hose off the engine will cut out. I'd check the first pipe coming directly off the turbo, it may be a bit loose. Either that or the one going to the throttle body - but check them all for loose clamps or damage.

Let me know how you get on, future readers always get annoyed reading a thread when someone posted but never came back to say what solved that problem.

WeeJimmy

One other thing, be sure the DV didn't fall apart when you fitted it and that it's tightened fully/orientated correctly (connector pointing straight down - there's a locating dimple on the DV and if it isn't in the correct position the DV won't seal against the compressor housing), they come apart easily and there's not much room to work in there so it's easily done, I know because I've been at mine a few times recently lol.

The surging at idle is a funny one, usually that points to a vacuum pipe but our cars don't really have any, maybe a couple.

Willing to bet that's the symptom which will lead you to the cause.

WeeJimmy

Sorry, just realised it throws a P2261 for the GFB DV+ due to it operating in a different way from the stock one.

I have only had the P0299 code a couple of times.
In my case it was due to the N75 (boost/wastegate control solenoid) being disconnected and only running wastegate pressure.

Perhaps it would be an idea to change the N75 if you can get one, they're inexpensive.

crapi77

Hey WeeJimmy, thanks for your reply. I learned something new regarding the Diverter valve with regard to the performance oriented GFB DV+ version because of your post. I wish I would have known about that before I bought another from Audi for the same price. I will keep you/all posted after I figure out my problem. I have noted that the PCV valve appears bad so I am going to replace that along with the cam follower seeing that area anyway and I don't know the status of the cam follower. I will also check all the hoses as you offered as well. Cheers!! Dave

WeeJimmy

No worries Dave, the DV+ is good for running higher boost, if you buy one, it is possible to remove the thicker spring that comes with it to run it in the stock fashion - meaning it will no longer throw a P2261 but will still hold more boost and be more reliable. Worth the money for peace of mind.

I did consider suggesting the PCV valve as it is linked to the intake manifold but best to eliminate one thing at a time. The pipes connected to it can crack too so check them very carefully. Don't recommend the delete plate, better with the OEM valve.

Good call on the cam follower, mine had the roller conversion fitted allegedly but I plan to check it while I do the timing chain/tensioner in a couple of months.....this car is driving me insane, all thanks to me letting a garage work on it instead of just doing it myself like I usually do.

Hope it's something easy and simple to fix buddy, fingers crossed for you.