P0299 Underboost CEL and questions

[humphrey111]

Turbo out of spec. Replacing under warranty.

Pretty generic, but I guess it doesn't matter beyond that. Just glad It's being taken care of.

 

[Maddmatts]

I just came across this vid that shows what the TSB is talking about. Ignore the VW specific stuff, our turbo assembly is much easier to gain access to.
https://www.youtube.com/watch?v=7fk6cSDE3hE

I also found that this exact problem is being encountered on Dodge's 1.4T who also uses turbos from Garret.

 

[pljenkins]

Great link, Maddmatts! Thanks! I've got one with around 93000 miles on it and it's been throwing (very) intermittent P0299 codes. It hasn't happened in about 2 weeks and I thought at first it was underboosting because it was over 105 degrees outside (Ah, Texas in the summer). Hasn't thrown the code in quite a while, but this gives me something to look at and see if it's doing what he says it might be doing. Gonna be tearing into it tomorrow to do the 100K stuff like new plugs, new belts, radiator flush.... Good times.

 

[ben416]

I've had this issue, it only seemed to appear under heavy load. I have a Trifecta tune and thought the most recent tune update was the cause of my lack of boost. 17-18ish vs 22-23psi. Then the underboost p0299 issue started occurring (putting me down to 7psi) months later when I was towing my motorcycle trailer or had other people in the car while under full throttle up a hill at highway speed. Situations where the turbo would be hard for extended amounts of time. Pulling over and tapping the arm on the actuator seemed to get it back to 17-18psi for a while.

Eventually I got the p0299 code to show for the dealer by luck but they didn't know what to do. I eventually convinced them to just replace the waste gate actuator and I got my boost back. Probably gonna get a chance to take the bike and trailer on the highway this weekend and I'll see how it holds up. Their explanation after applying the repair was due to my use of the trailer I must have been causing the actuator to run through its full range of motion, thereby causing it to bind at times.

 

[RaceThisLTZ]

I have had a loss in power for 4 months now. Its a tuned car and boost usually would go to 20-21 lbs under higher load conditions. The car now is lucky to hit 17 and probably not hit that till 4000-4500ish. I get a "PENDING" Code P0299 on my ultra gauge all the time.
Have examined the waste gate pin and found excessive wear with a lot of slop. I have been trying to drive the car till is actually throws a CEL but it just stays pending. Coming up on 100000 miles so unless i can somehow get the dealer ship to examine the car (might be worth paying them to inspect the turbo) Ill probably be buying a turbo next spring.
Car just sucks to drive like this.