I has having issues holding boost past 15psi and I noticed my boost gauge needle fluttered a lot sometimes but not other times. Since it was so random I chocked it up to be the valve itself and not just a leak somewhere.
After replacing the valve my boost now holds at 19psi and no more fluttering of my boost gauge needle. I had an old version of the diverter valve which was 06F 145 710 B. This valve has a pretty bad track record and I replaced it with a 06F 145 710 G, which at the time of writing was the latest version(06H 145 710 D, is now the latest, features piston instead of diaphragm). Here is how I replaced the diverter valve.
Tools: Metric allen wrench set (sorry didn’t take down specific size) Flat head screw driver. Optional Tools: Short socket wrench with allen sockets. Typical sized socket wrenches are too big but the half sized ones work perfectly.
I find that getting to the diverter valve from underneath is the best way, Its too far down from the top side to work with.
IMPORTANT: Make sure to let your engine cool down first. The diverer valve is near the turbo and many other hot pieces. These pieces are extremely hot.
ALSO IMPORTANT: Make sure to jack your car up correctly and use jack stand. See your owners manual for details if you are uncertain.
- Jack up your car on the passenger side. I also suggest using jack stands since you will be spending time under the car.
- Remove the skid plate. I find a short stubby flat head one works great for the screws holding the skid plate on.
- In the picture above you will see where the diverter valve is located. Its where the turbo is behind the engine almost straight up from the passenger side axle.
- There will be three allen screws that need to be removed. Mine had loctite on them so they will need some effort to get free. This is where the short socket wrench with allen sockets really work great.
- Use a flat head screw driver to undo the power adapter
- Reverse the process and you are all set!
The hardest part of this is finding the best angles to get the allen screws out. Some places can be very cramped especially the top side allen screw.