a4 loss of power

[nevets74]

hi all ,im having loss of power now and then audi a4 1.9 tdi 2005 , b7. as in going in to limp mode no engine management light comes on. okay after i stop and restart. all is good for a couple of weeks then happens again . ive changed the maf sensor ,fuel filter ,oil and air. any ideas .thanks

[spazmatron]

has it got a dpf

[zollaf]

code read, you need a code read. this will then give something to go by other than guess work.

[nevets74]

hi thanks for the reply im not shure if it has one i will do some research .

[nevets74]

i got code 16618 p0234 coming up if this helps thanks. seems to be after i go round a roundabout.

[zollaf]

you have too much boost from your turbo. the engine is going into limp mode to save damage. can be turbo carboned up and needs cleaning, or n75 etc..

[nevets74]

thanks zollaf. whats n 75 is it easy to change? etc plenty of power after i stop and restart engine when it hapens then runs fine for a week or two but always happens on same route . eg after roudabouts then put foot down 3rd gear 3000 revs then it hapens again.

[zollaf]

follow the small pipe from the turbo actuator. this ends at the valve. it controls the amount of vacuum the actuator gets and hence boost. first though, apply a vacuum to the actuator and measure how much it moves and that it moves smoothly. iirc 19mm rings a bell. any less and the vanes are clogged. working the actuator for a while can free things up for a bit and if its ok for a while then it points to the turbo.