[JohnHuson]

N47 2008 E90 320D. Juddering poor acceleration. Reduced power. Changed EGR. No leaks. Tried replacement MAF off another car. Stripped turbo, spooling OK and sounds good. Not sure about actuator but bench test seems OK, it moves up and down. Waste gate is free.
It drives like its a Kangeroo, then runs breathless. It gives impression it is short of fuel?

I can hear the turbo blowing when I floor it but I end up with a pedal that produces no power but then will give intermittent engine response.

No smoke. No excessive fuel which still seems like fuel starvation but how can that be intermittent within a few seconds?

Thanks for your answers but if your knowledge produces wild guesses I have had them all and I could have spent a fortune exploring them.

No OBD codes showing.

[Andrew@FixMyVW]

Originally Posted by JohnHuson

N47 2008 E90 320D. Juddering poor acceleration. Reduced power. Changed EGR. No leaks. Tried replacement MAF off another car. Stripped turbo, spooling OK and sounds good. Not sure about actuator but bench test seems OK, it moves up and down. Waste gate is free.
It drives like its a Kangeroo, then runs breathless. It gives impression it is short of fuel?

I can hear the turbo blowing when I floor it but I end up with a pedal that produces no power but then will give intermittent engine response.

No smoke. No excessive fuel which still seems like fuel starvation but how can that be intermittent within a few seconds?

Thanks for your answers but if your knowledge produces wild guesses I have had them all and I could have spent a fortune exploring them.

No OBD codes showing.

What scan tool are you using?
Does your fuel filter need to be changed?

[ingenieur]

DSC light flashing only when the juddering occurs? Perhaps wheel speed data is causing this - are all of the tires the same brand, size, and circumference?

[Yozh]

OP is probably better off in the European section since they had been playing with N47 for much longer.

[Jet Wrench]

I have a euro spec 320d 225,000 km. It could very possibly be the intake manifold MAP SENSOR is dirty/defective or cracked/deteriorated vaccuum lines from the pierport valve to the turbo accumulator. Check the accumulator for cracks as well