paulhenderson

Here goes:
Car: OCty Mk1 1.9tdi 110bhp elegance
Problem: Goes into limp mode around 3000 rpm when revved moderatley hard.
It will do this once or twice, i simply turn the engine of and back on again and this cures the problem.
Steps taken to fix the problem:
Replaced MAF, slight improvement in power.
Replaced N75, slight improvement in power and I can hear the wastegate from the turbo working again on lift off.
But the problem still persists, is it by co-incedence that when i replaced the above parts i got the slight improvements in power?
I ran vag com and got error code:
17965 P1557 Charge Pressure Contr. Positive Deviation
Took it to Skoda dealer and they said it was sticking vanes in the turbo, which i dont believe as the problem only happens when the engine is cold and if after the 1 or 2 re-starts the problem will not re-appear for the rest of the journey...
Any ideas?
Thanks.

fordfan

Their diagnosis seems correct to me. The turbo has vanes which direct the exhaust gasses onto the rotor. The angle of these vanes determine the amount of boost that the turbo gives, it doesn't have a wastegate as such. If these stick in the wrong position the turbo is giving too much boost and the ECU shuts it down until it is reset by turning the ignition off and back on.

The official fix is to replace the turbo, however it is possible to remove it and clean/free up the vane mechanism.

This should provide all the answers:

VNT Repair Procedure - TDIClub Forums

BigGar

Had exactly the same problem with my 52 Reg Octavia 110TDI last year. Also had the same fault code as that.

Ended up with a new turbo (under warranty) and no problems since. When taking a look the mechanic said that the VNT actuator was not working correctly. It was a sticky turbo.

KenONeill

Sticky VVT mechanism or vanes was my first reaction too, before I even opened the thread.

Taxi 219

Turbo time by the looks of it unless a succesful clean can be done

__________________
Car now: 56 Octavia MK2 1.9TDi Ambiente-Debadged-Metallic Flamenco Red DMF Reqiured soon
Previous: 06 Octavia Mk1 1.9TDi Classic with + pack-Diamond Silver
Sadly missed: 97 Nissan Primera 2.0TDi SLX- Red
Paul

mbames

Got to be worth a stab at cleaning it first.... much cheaper :-)

paulhenderson

I think im gonna have a stab at a clean job as the car is out of warranty and I dont fancy paying 700 or 800 for a car that only worth about 3k. Will keep you all posted as to the outcome!!!

Thanks for all the replies, much appreciated.