VW Golf 2.0 TDI - sudden loss of power

[george2005neil]

Hi, i posted this in another section but think this is more appropriate so will delete the other. Hope you can help. My wife's car started to experience these symptoms about a year ago. They are now becoming more regular, I've been reading a lot about this but frankly, having just about the ability to change a tyre and an air filter, I'm a bit worried about gettng stung by a garage without getting sorted - will pay to resolve but money at a premium so keen to take a considered approach as we can't replace the car. It has done 150k miles now - had from new.
There is some context too. It appears to happen at around 2500/3000 revs and when I change gear (typically from 3 to 4 or 4 to 5) at around 50/60 mph. Car continues to drive but there is no turbo when it goes and then struggles on hills / inclines. The strange thing is that when we turn the engine off and back on again it just disappears - but it's now starting to happen every other day.
I used a mechanic for a number of years who did start to look at this. He got the VAG COm thing and must have taken some codes. I remember him saying he could clean out something first, if that didn't work he would replace but said no guarantees that would solve. The engine light is on and I get a warning saying 'emissions garage' when I start the car. Anyhow, he has now packed up - and I'm a bit stuck as to what to do now. As I say I'm reluctant to go to a dealer as feels like they will just say turbo has gone and there appears to be all manner of resolutions to this. I've read about cleaning a MAF/MAS, replacin them, cleaning turbo with innotec, pipes, EGR.....
My plan was to see if there was anything 'basic' I could do myself and then go and find someone to see what the codes are and then take it from there.
Interested in other experiences, advuce on next steps and guidance on what I could have shot at myself.
Now the ironic part. I have a Audi A3 Sport 2.0 TDI 2005. It happened last week on that too.
Thanks in advance.

[vag_tech]

We can help you most efficiently if you can post the codes along with freeze frame data.


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[george2005neil]

Thanks all. Quick update...
Asked few friends and work colleagues, two seperate people recommended same mechanic and he's coming out on Tuesday to run the codes on the Golf.
I'm also thinking maybe doing the 'revive' on the Audi.
Will keep you posted.

[george2005neil]

Guy came today and ran the computer on the VW Golf….

16785 and 16618 codes found.

16785 relates to EGR and 16618 overboost.

He seems to remember the EGR code was the one that came up when he MOT'd a few months back. He thinks the EGR is on it's way out but not the Turbo, he said he'd price up a new EGR and cleaning of the Turbo and come back to me. He reset the codes and will run another check again to see if the EGR comes back on. 20 min drive home and the engine light hasn't come on yet.

In addition, I have bought some revive for the Audi - no issues since I last posted with the Audi and no lights.

[george2005neil]

Just another thought which may or my not be related to the above.
Context is typically this. It's a really hot day. The drive is about 2 hours plus, this year these conditions happened twice. We start with the air con on (lowest setting on temparature) and fan setting 1. As the journey progresses, we gradually have to turn up the fan setting and the strength of the blower gradually reduces. At 3/4 hours into the journey - we are on setting 4 and there is nothing coming out of the air flows. The fan motor is buzzing away, high strength but nothing is coming out. I also remember seeing a wet patch after the car had been stationary. As I say, it happened twice this year but never though to get it checked when we got back as we never had the issue again. Related or not do you think?

[niall campbell]

Forget cleaning the turbo, go for a genuine egr valve rather than cleaning it out . It wont be much more, just paid £ 130 for my A6 one

you need another scan for the heater motor, is the Aircon on ?

I would try heater with the Aircon ON and then on ECON mode

I would also be replacing the cabin filter (s) , either 1 or 2 in the box incase they are blocked up

There are several motorised flaps that move and can be prone to failure in the heating.

[Teflon]

Likely your power loss and over boost code is either a MAP sensor or a gummed up turbo. First option is cheapest, second is way more common.

Don't know why Niall says don't clean turbo, it would fix it completely. But it has to come out and, be stripped on the bench. Forget snake oil solutions that you pour in, or oven cleaner or anything else that doesn't involve doing any proper work. They might give you some peace of mind for a week or two but it's not a permanent solution.

Heater is something else. If you've got a wet carpet, chances are you have a leaky heater matrix.


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[george2005neil]

Hi all, I wanted to provide an update. While I wanted for pay day - the guy suggested I use some of the better diesel, he'd heard 'some'reports that this helped. So we've been filling with the Shell V-Power and BP ulitimate although it does grate at 10pm a litre. It did actually help - the loss became less frequent to the point where it was sometimes not occuring. I had the the vanes cleaned yesterday, using the Mr Muscle - he said they were pretty coked up and that that there was some 'give' in the vanes. I super ride home - they whistling came back as the turbo kicked in. Within 24 hours it's back. No engine lights coming on now, occuring more at 3250 revs now as opposed to 2500/2750 revs before.
So the EGR valve has been replaced and the turbo vanes cleaned, better fuel in. What next do you think?
Will take back and get the codes read again but guessing they'll throwup the same one.
Frustrated.

[Rob69]

I wouldn't consider your VNT to have been cleaned by the mr muscle method, probably just dislodged some crud and moved it to a different vane position.

[george2005neil]

I mean he removed it and cleaned it by hand - with Mr Muscle