Loss of turbo........ code 17964...Help!!

Hi all, I am new to this, so I hope I have posted in the right area?

I have been trawling through many forums lately trying to diagnose the turbo loss I am experiencing with my A3 TDI. But I am still at a loss and hoping someone may be able to help me further.

Car is Audi A3 2002 1.9 TDI Quattro Sport ASZ. Done 150k miles

For the last month the car has been losing the turbo/going into limp mode? when hitting around 3000 revs or around 60mph. I can hear the turbo hissing in the lower gears and the car pulls (however the turbo is more delayed than it used to be), but when I get to around 60mph I feel all pull drop from the engine and this usually nippy car is struggling to accelerate up a slight hill on the motorway. Which make for a fun commute to work!

I initially had two error codes:

MAF - Which I have replaced, but to no avail, and
Fault code: 17964: charge pressure control negative deviation

I still have the 17964 code.

I have checked all pipes & all were OK, except for the intake pipe into the EGR value, this seal and metal clip had popped. I fixed this but still same problem. I cant see any cracks in other pipes. But might have missed something, so I will give the pipes another thorough look over.

Next I have replaced N75, N18 and another value in the same area (not sure what is was but changed it anyway). Still same problems.

My mechanic has been saying its a blow turbo from day one! Hence why I have had a go at fixing the problem myself first, as I am not happy to just go buying a new turbo straight off. Esp after reading so many forums about the multitude of things that can cause this blasted code.

Any more suggestions of what could be causing this code/problem would be most appreciated! Although I fear I am heading down the new turbo route!

Hopefully this link will help you somewhat.

http://wiki.ross-tech.com/wiki/index...4/P1556/005462

One of the Techies should be along soon ;)

Thanks Chris, I have seen this. Not very specific is it? I think I have attempted most of the solutions. But no joy yet. Looked at pipes again today. Looks ok. I have also read it could be my actuator. But the rubbish Haynes manual I have suggests it's part of my turbo & can't be replaced seperatly. So still stumped! 😊

17964 is under boost and in most cases this is due to a vacuum leak in the system. I know you have checked them but you need to check them again. Take off the small 3-mm pipe to the servo feed pipe and apply a vacuum to it using a hand pump or if you must, the Mk1 mouth. You are lucky that it is not showing 17965 as that nearly always means turbo off and getting the turbo off an A3 TDI 8L quattro is an absolute pig of a job that is easiest with the gearbox out as the transfer box seriously hinders access to the turbo...a really unpleasant job.

Thanks for the advice Crasher. I finally had a chance to take the car to a VAG specialist today to have the codes checked again following the work Ive done. I now have code 17965! :-(

The garage found 3 issues. 1) turbo creating over boost, so dropping into limp mode. 2) turbo boost pipes are worn at intercooler joints. 3) Mass Air flow low.

They are saying turbo is getting stuck. They have suggested new turbo! :-(

Should I do the intercooler pipes before getting a new turbo. Or would you agree it looks like I need a new turbo?

Thanks

17965 is classic clogged turbo actuating ring, don't pass "go" and don't collect £200, pay out nearly a grand instead...