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Hi all, I've seen few others have had similar issues with 1.8T or 9n3 GTI to be specific. Looking for some advice (I purchased the car as it is and am not mechanical):

I have taken the car to a few garages to try and get it fixed however seems no-one wants to work with it unfortunately.

Symptom:

When on cold start (around 1/3rd of the time) the car goes into limp mode and boost is VERY limited. However this is rectified by simply restarting the engine. I did find a few months ago that it would also go into limp mode when I was driving it heavy however since I serviced the Forge 008 Recirc Valve it does not appear to happen while driving and only appears to happen at cold start now. I do also find the sometimes (When boost is working) it seems to boost more at around 70% throttle than it does at 100% throttle.

Error Code the car throws out : P1297

Potential Causes Considered:

Forge DV - (Ironed this out with servicing it)
Boost Leak - (Mechanic mentioned that there was no leaking in pressure/Smoke test)
I've heard some say it could be N75, Dirty TB, Pressure issue, MAF/MAP sensor, TIP.

Mods:
Exhaust
Forge Turbo Silicone Hose
Forge 008 DV
Previous owner thinks it was Remapped a few years ago

If anyone has any experience with a similar issue or perhaps any 1.8T experts here that would be much appreciated if they could pin point me to the component/cause of the issue. As mentioned I've tried speaking to many mechanics, however they simply look under the and see the Forge Hose and DV and seem to instantly stray away.



Jack

Limp mode doesn't necessarily need to be connected to a boost issue. It's more likely the other way around.
Since it's limping, it's limiting boost.

Especially, since you're in limp mode upon cold start up, I don't think boost is the issue here.
Best is to read the DTCs (error codes) from your engine management controller and see why it is going into limp mode.

The OBD reader picks up just the following code: P1297 Pressure Drop between Turbo and Throttle Valve (check D.V.!)

As mentioned I did check the DV and service it. (Actually its a Recirculation Valve) cleared code and on the first start after clearing the same issue happened again.

The garage recommended I have a chat with a diagnostics expert, I will update when hear back from him

The diagnostic guys seems to have found that the code populates once the engine reaches idle for the first time after being turned on.

I.E if revving the engine when turning over the ignition and holding minor revs - no code populates until you stop.

Also no boost leaks found at all, MAF if reading correctly, DV also holding absolutely fine.

I know there are some 1.8T gurus out there on this forum, please speak up if you have any idea.

Just what the Ross-Tech wiki says:
http://wiki.ross-tech.com/wiki/index.ph ... 297/004759

Might be a good place to start.

PS - I love my VCDS.