[chittychittybangbang]

The n75 boost solenoid is on the firewall above the brake booster. It controls the boost that the turbo puts out. Most of the time, it's not broken, it just needs cleaning with carb cleaner. The vacuum lines going to and from the solenoid can also crack and leak air. This would be a good time to clean the solenoid out and replace all of the vacuum lines as well.

 

[chittychittybangbang]

I noticed that this topic comes up on the vw vortex a lot as well.

This poor guy was told that he needed a new turbocharger, the likely culprit was a number of problems probably piled on top of each other, the vacuum lines, the MAF, and possibly the n75.

http://forums.vwvortex.com/zerothread?id=3302944

this guy lost boost, probably a similar problem.

http://forums.vwvortex.com/zerothread?id=3289341

I will do a writeup on power loss problems and limp mode.