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Golf mk5 GT Sport TDI - 2008 Golf mk5 GT Sport TDI Turbo issue - DarrenH

hi all,

I have a 2008 mk5 gt sport, TDI (170 bhp) which has recently had a turbo issue. When acceleratering, the revs get to 3,000 rpm, the turbo kicks but almost instantly dies. If I keep my right foot planted the turbo kicks again but drops instantly.

I have had the car hooked up to a computer but as there isn't an engine fault light on, there is nothing showing.

I have also taken the air flow meter off but this hasn't worked. I'm happy to give it to a specialist but like working on cars so am happy to try a few things!

thanks in advance.

Darren

Golf mk5 GT Sport TDI - 2008 Golf mk5 GT Sport TDI Turbo issue - Railroad.

Sounds like the classic signs of the vane ring stuck on the exhaust turbine of the turbo. You can cure it by removing the turbo and stripping it to clean it, or you could try Innotec Turbo Clean. A google search should enable you to find it. I've used it and it does work.

Golf mk5 GT Sport TDI - 2008 Golf mk5 GT Sport TDI Turbo issue - DarrenH
Railroad, thanks for the advice. Looking it up on line it looks like a biggish job!

Could it be anything else?

Thanks
Golf mk5 GT Sport TDI - 2008 Golf mk5 GT Sport TDI Turbo issue - The-Mechanic

If the engine is going into limp mode from an over boost condition I'd expect it to log a P0234 error code. What scanner were you using ? If it was a generic EOBD cheapie then they sometimes won't read the errors. You'd be better off getting VAG COM plugged in as it's far more reliable in these cases.

As railroad said, it's possibly the VNT mechanism either sticking or seized but another possibility is the vacuum actuator sticking or diaphragm split ? Other possibilities are boost pressure sensor fault, split/leaking turbo hose or intercooler, even maybe the coolant temperature sensor ?

Get the error memory read on good diagnostic equipment and also read the actual values of the boost pressure, coolant temp etc as just scanning for codes is only half the story. You need to see what the values are when the fault occurs to give a clearer picture.

Do this first, then you'll have a better idea as where to start looking for the solution.

Good luck, and keep us posted.

Golf mk5 GT Sport TDI - 2008 Golf mk5 GT Sport TDI Turbo issue - Railroad.

The turbo actuator diaphragm can be very easily checked using a hand held Mityvac vacuum pump if you're able to lay your hands on one.

I also have VCDS (formerly known as VAGCOM), and Im in Hampshire if that's of any help to you.

Golf mk5 GT Sport TDI - 2008 Golf mk5 GT Sport TDI Turbo issue - Morris Marina 1.3 Super

Don't ignore physical checks - vacuum hoses, boost hoses.....check that the vane controller on the turbo can move through it's full range. If the vanes are coked up it will need a push with a screwdriver but don't force it.

 

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