09_a4_in_dfw

My 2009 A4 [just over 130k miles] recently started throwing code P0299.
When the code triggers, it feels like the computer is backing-off the power.
As soon as I clear the code, the power is returned... until I trigger the code, again. <sigh>
I could live with the code if it didn't cut the power so much.

Most of my WWW searching yielded posts stating folks replaced bad diverter valves or the entire manifold/turbo assembly because the wastegate was leaking.

All the pages and videos I saw for bad diverter valves showed the older version of the valves. I removed my valve, and it is a newer version.
How do I know if a new-style valve is bad? This page talks about it, but doesn't give me a solid answer.

The videos I saw that blamed wastegates showed the wastegate puck loose in the housing.
What I want to ask is... has anyone ever modified the arm of the wastegate actuator to be just a wee bit shorter so it pulls that puck hard enough to close it completely?
It seems a huge waste to swap the entire manifold/turbo assembly for a simple flapper. $$$

Can someone with a "bad" assembly do this "test" for me?
Remove the actuator arm and tell me if the wastegate can be closed a bit more if it were only a bit shorter...

I tried to remove the actuator with the turbo still on the car, but I just couldn't get to the E clip on the end and the two screws that old the acutator to the turbo.
Anyone have any tips?

Thanks,

Bink187

I think in that video they could jiggle the rod/flapper by hand, if your car has been sitting parked at least 90 mins or so go out an see if you can jiggle yours. Mine is locked in place no play. A used turbo can be had, but who knows how it was treated. A new better turbo and tune can go north of $3K quick, but you will also replace everything in the boost path to reach the highest possible gains...and our motors at 130k may not want to push out an extra 200+ hp and tq

nofx1981

Here's what you're looking for
https://www.audizine.com/forum/showt...Flapper-(P0299)

09_a4_in_dfw

That is exactly what I want to do!
Not quite sure why that isn't the 1st thing folks try.

Thanks for the link!

Bink187

I would think this type of mechanical fault, would cause a constant under boost condition, not the intermittent P0299, but I am in no way an expert. That and no noise from the turbo, I attempted to jiggle the rod to no avail. So, I went off in another direction. Still no codes pending.

09_a4_in_dfw

I modified the arm on my wastegate actuator.
The shaft that goes through the wastegate arm shows significant ware, so that along would have caused slack in the wastegate operation.
I shortened the arm, and I now have boost when I need it.

I'm happy with my low-dollar fix... even if it only lasts a few months...

nofx1981

Awesome, glad to hear! I'm planning on doing this myself in the near future.

AudiA4209

I have the same issue! I bought a new Diverter valve and when i went in to replace the old one, it already had a new diverter valve in place. But this one also had a spacer in there too..... can spacers cause underboost aswell if they are messed up? Or would wastegate be the only thing worth lookin at

Bink187

What I find most disappointing, Audi has collected so much data from all of these cars. But has only come out with a diverter revision as the answer. As mine popped again yesterday, it was leaving off the line at the light, other conditions: Florida heat, low oil level, and traffic. Stop at the gas station to read the code. checked the oil in car and at the dip-stick. Add 1/2 a quart cleared the code.

Bink187

Code popped this morning. Only common aspects are leaving off the line, and traffic today. Oil level is good,and it was about 81F.