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P0299 Fault Code, Please Help!

Mango1984 Aug 19, 2014

  1. Mango1984

    Mango1984 New Member

    Hi all,

    Firstly hello as I'm a new member! Yay!

    Now moving on....lol

    I have 2009 Audi A3 2.0 tdi..........With a problem.

    The other day I was running really low on diesel so I was on the way my the pumps to get some, as I was on a dual carriageway doing approx 70 in 6th at 2000rpm ish my glow plug light came on and started to flash.

    Instantly the car lost power (limp mode) and the glow plug light continued to flash it's self silly. The car was still drivable but felt like there was no turbo boost, and was just like driving my other halfs 1.2 fiesta!.

    I made it to the pumps, re-fuelled, turned on the ignition again and all was good. I went around town in the car, Did some short runs (never going over about 50mph) and it was all ok. I'm not a slow driver and tend to give it some red line once in a while and still the car was fine.

    A couple of days later while going to work,(again doing about 75 at just over 2000rpm) the same thing happened. I pulled into the hard shoulder, switched the ignition on and off and again all is well. Once I've done this reset it's as good to drive as ever. It's not burning any more diesel then usual so economy is unaffected, it's not making any whistling sounds, there's no smoke, there's nothing apart from this intimmitent fault.

    Again it doesn't do it all the time while at motorway speeds but 7/10 times it will.

    I gave it a thrashing for about half a hour ragging the bejesus out of it and it performed great, boost was there and the light stayed off.

    I decided to take it to a garage to let them have a look, but on picking the car up I'm not 100% sure I think there diagnostic is right.

    They say the fault code is P0299 turbo underboost, and they have said that there is a turbo hose that feels a bit soft and they told me there double walled and it may have collapsed inside. However, when I'm thrashing the turbo there's no lag, no nothing it drives faultless, it's only when I'm not really even in the turbo just cruising that this light comes on and the engine goes into limp mode, so I find it hard to believe it's the hose??? And I begrudge paying £150 for a job that didn't need doing.

    Has anyone experienced anything like this? Or can anyone shine any light on the situation?

    The engine is the CBAB 2.0 tdi.

    The car has full audi service history including cambelt and water pump dome 6 months ago and I change the oil every 4 months so it's pretty pampered and hasn't been abused.

    Thanks in advance
  2. studunc06

    studunc06 Member

    try the vacum unit on the end of the inlet manifold,sound similar to my problem,it would happen on motorways/dual carriage ways and i would give it a bit more gas on an incline

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