[ed200152]

Last winter I would have no boost until the engine warmed up. There was ice forming in the vacuum hose leading into cannister. Also the vacuum nipple rusted shut. For some reason moisture accumulated in the vacuum pipe and cannister. The return spring inside the cannister has become rusty or weak giving the VNT 15 overboost. The VNT vanes have been cleaned with EASY OFF and the lever is moving freely. A mechanic friend is replacing the cannister with a new Garrett unit. I'll report back with the results.

 

[Seatman]

There's good info in the faq for adjusting the actuator if needed, even mechanics need a bit of extra info sometimes.

http://www.myturbodiesel.com/1000q/a4/VNT-wastegate-adjust.htm

welcometomyturbodies

 

[ed200152]

I had the actuator replaced.
It would not hold a vacuum and the internal spring was weak. This caused the VNT to get carboned up because of the loss of the full range of motion at either ends of the stroke.
I also had the lower control arms and rear axle bushings replaced...what a huge difference the new bushings made(fronts are TT, rear are OEM). The Jetta now drives like it has 15,000 km on it. (now 187000 km)
This Jetta is the best car I have owned and I'm happy I stumbled across this informative forum.

 

[Seatman]

It's always good when the things you fix make a difference, I really don't like spending a pile of money and the car still feels the same, or worse lol

 

[TDI Schmitty]

How do you clean the VNT vanes with EASY OFF? I assume you have to pull the turbo off for that.

 

[chittychittybangbang]

How do you clean the VNT vanes with EASY OFF? I assume you have to pull the turbo off for that.

No, you just remove the 3x nuts holding the exhaust downpipe on. Then fill the exhaust housing with easy off and slowly turn the wheel. It would be even better to block off the exhaust housing so that you could fill the turbo all the way without having fluid get into the cylinder head valve area. I don't like this method because the easy off will get into the oil a little bit and it's very dangerous stuff to work with. Easy off can blind you if it gets in your eyes or cause severe injury if it comes in contact with you so be VERY careful with that stuff.