Potential air leak re turbo, help please

[bradski]

Hi guys, i'm looking for a bit of help as I have a problem with my A4. Basically the car runs quite inconsistently and I think it may have an air leak near or to do with the turbo. Sometimes when i drive the car, when the turbo kicks it, its really torquey and seems to pull like a train. Other times when I drive it, it accelerates really flat, almost like the turbo isn't working. I've changed the petrol filter as we suspected it could be that and it didn't solve the problem but also no engine lights have come on so it hasnt registered anywhere on the computer.

I just wondered if there were any known common places on the engine/system where there could be air leaks or split hoses/pipes etc? I also have a small feeling that brakes may perform differently in relation to how the turbo performs (this is just a hunch) so thought it could maybe be a vacuum pipe?

Any help is really appreciated as this is my first Audi and would like it to drive how its supposed to!

Thanks in advance

Bradley

 

[stu_m]

I would scan it for any faults as it sounds like its in limp mode at times

 

[beachbuggy]

Sticking actuator? If it gets stuck open then you'll loose boost, becomes unstuck and boost comes back. Either that or you have the opposite and your actuator is locked closed, either leak on pipe to actuator or faulty n75 this gives strong boost minute , lip mode the next when you've over boosted. Scan it for faults and check for vacuum leaks