As promised, here's how I replaced my turbo boost "controller". This is on a 2007 Conti GT and it is for the one on the passenger side of the engine, US version.

The best info I could find suggested that the entire front had to be removed; Bumper cover, radiator, etc. I found a way to remove less of this and thus hopefully making the job a bit easier. The controller is so buried that it can't even be seen without removing quite a bit. At a minimum the front bumper has to be removed and the radiator, radiator fan, AC condenser, cooler, core support have to be moved out of the way. They CAN be totally removed but don't necessarily have to be if you are good at working in small spaces.

What I did was to totally disconnect the core support and both top radiator hoses from the radiator. I tried to leave the driver's side radiator hose connected; don't leave it connected or the connection part of the radiator will break. Don't ask me how I know this. Cheapest radiator I could find was $800 US. Disconnect both. Draining the radiator through the bottom drain will make this job easier as the entire radiator will be significantly lighter. I did this before disconnecting it.

There will be a few plugs to disconnect for the fan, and other sensors on the top of the core support. Once all of this is done, place something under the core support to hold it in place once moved out. You can then "swing" the passenger side out away from the engine thus giving you access to the controller. This procedure keeps you from having to disconnect the condenser and cooler.

At this point, removing the radiator fan will give you a little more room and there are only 4 screws holding it on from the back. Well worth the extra 5 minutes.

You will now have access to the controller although limited. You will have to get in between the radiator and the engine to see just WTF is going on. The controller is still somewhat buried but at least able to be replaced. A long pair of needle nosed pliers and a shiite load of patience will be required for removal and replacement. To make the job easier, I cut the short rubber hose to help with removal. I also used easier hose clamps on the new controller once installed. Lot easier getting a screwdriver into that space than a hose clamp compressor..

I replaced the controller with a Audi VW Turbo Boost Control Valve - Febi Bilstein 06A906283E. So far so good and only $60.

Finally I would give this about a 7 on a one to ten scale of difficulty, one being easy, ten being a nightmare. I have a lift and tons of tools so maybe it was easier for me.

Hope this helps,
Ron


Top view

Passenger side view