A4 2.0 tdi quattro P0299 loss of power

[Sarah_Georgey]

Hi team,

Sorry this may be a long one.....

I bought my Audi A4 2.0 tdi quattro off of a friends Dad in October - full Audi service history and he took out the extended warranty...because he could.

Car drove fine for a couple of months then suddenly started playing up. When accelerating it would suddenly started juttering unless you reduced power. This was an intermittent problem and wouldn’t happen all the time - plugged it in and got code P0299 Turbocharger Supercharger Underboost.

Took it to Audi for a service and to investigate the issue - apparently all was fine and it may just be an electrical fault drove it for a while with no problems, no fault codes and boosting. WINNER!

Long story short, problems back and worse than before. She struggles to start. If I rev over 2k the ignition coil light comes on and goes into limp home mode and get code P0299. No smoke. No boost. Fuel consumption is s***!

I’ve checked boost hoses and all seem in tact as best as I can see. I’ve bought a new diverter valve and gasket so going to fit these Friday after work but she’s basically undriveable!

Any other ideas what it could be?!

 

[S4_dan]

Check all boost hoses, could be a split. Check all vacuum hoses are good and secure. When was the fuel filter last changed? Are there any new DTCs stored in the ecu?

 

[Avant1]

What year is the car ?


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[Sarah_Georgey]

Check all boost hoses, could be a split. Check all vacuum hoses are good and secure. When was the fuel filter last changed? Are there any new DTCs stored in the ecu?

Boost hoses were all fine, vacuum hoses were secure. Fuel filter was last changed in the service April:May.
Think you jinxed me, on start up on Thursday morning I had code P0473 come up, never had this one before. It’s since come up occasionally on start up so going to get a new sensor.
Changed the diverter valve yesterday, the egr and butterfly flaps on then inlet manifold were coked in carbon so cleaned them off and refitted with new gasket. She runs better initially and can hear the turbo working but jutters as if there is a fuel pressure issue but no code for fuel - going to change the fuel filter again and see if this makes a difference.

What year is the car ?


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It’s a 56 plate

 

[Avant1]

Check the fuel pump relay in the ecu box for water damage .



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