MK4 1.9 TDI 115 - Power Loss on Acceleration

[Gaz W]

Hi Guys,

Am hoping that someone has come across the issue before, its a bit of a strange one!

Overall, the engine is fantastic and pulls well etc, however if cruising at motorway/dual carriageway speeds (e.g. 40-60), if I then accelerate e.g. to overtake in 5th/6th gear, after a few seconds the engine feels as though it looses power often with a noticable 'jolt' as if i've pulled off the accelerator quickly. With my foot to the floor I can maintain my current speed but there is no acceleration/power to speak of, even if I change down a gear.

 If I then slow down, e.g. pull off the motorway and go to accelerate away from the junction after stopping there is no power at all, and acceleration is very slow even with foot to the floor.

However, re-starting the engine cures the problem and it is then fine, until the next time I accelerate!

Any ideas of what could cause this? I have done a VAGCOM scan which throws up nothing.

Thanks!

Gaz

[EsSeX dAn]

thatll be the notorious limp mode problem. basically the vnt veins stick open so it overboosts, which then shuts the turbo down
only way to sort is by cleaning out the turbo, remove it, strip it and clean or send to rtec to do it or fit a new turbo

[Hoggy]

Could a dodgy egr valve not throw up a similar problem?

We've had similar in at work, egr valve sticks open, no turbo pressure, bosh limp mode, would be more likely to throw up a code but not all the time.