Power loss and shuddering

[LosingMyMind]

Audi A5 2.0tdi Quattro 2010 manual

hi everyone.

ive recently got a car that I'm having issues with where if I drive the car hard when it gets to aboveboard 2.5k revs it will start to shudder and loses power, if I creep through the revs it will drive a bit better, not much, but a bit.
It was scanned and it threw up a fault code for the throttle body so it was replaced for a new one and I also cleaned the egr valve but the problem still happens.
if I continue to drive the vehicle when it's shaking the engine management light will come on and it loses all power even if I put my foot to the floor.

i need this vehicle for work so need to get it sorted.

ive been given all sorts of advice... some say it seems fuel related and some say it's possibly turbo related.
i just don't know where to turn.

ive attached a picture of the fault codes from when it was scanned . Please can someone help me out IMG_0519.jpg

[Crasher]

From the fault codes I would say the turbo actuator is not moving when commanded and it is vacuum controlled. It could be a leak in the vacuum system or a punctured diaphragm, there is no official repair kit or procedure for this apart from a rebuilt bench tested turbo. I can barely read the first code but can make out fuel pressure to high, this could be a faulty sensor or faulty regulator. If you remove the regulator, it MUST be replaced so don't remove it unless you are sure it is at fault.

[LosingMyMind]

Thanks for the response. The first code is p008800.
How would I check if it's the high pressure fuel regulator before I remove it ?

[Crasher]

P0299 can be a software issue but firstly the turbo's vacuum control system needs to be checked for leaks, if there are none it may be worth having the software version checked and a VCDS code read would show the information, ideal you would want to have the latest highlighted level which is in bold.



P0088 worries me as the usual code is P0087 BUT the Audi Technical Product Information notice 2026879/10 does also include P0088 in this TPI. Basically this is a nasty one, fuel system contamination. It states this can be due to system contamination by bad fuel and also miss fuelling with petrol but we have also seen this after a new fuel filter has been fitted and the engine started without firstly priming the system. The first step is to look inside the fuel filter to see if there is metal swarf in there and then the valve taking note of the note....

[LittleAl]

Having recently cured a similar problem in my Tdi Passat I'd say start with the basics. Check every hose and vacuum line you can find for integrity. In my case a line had come off down by the egr valve/ anti shudder valve. Every time I got to 2200prpm I lost power and the DSG gearbox couldn't work out whether to change up or not causing a bucking motion. It was entirely my fault because I'd had the egr off to clean it because it was blocked solid. ��