Hi
I have a 95 audi 80 1.9 TDi. I was due to part exchange the car on Monday so I went away for the weekend thinking it would be our last drive together. 145K and I have never had any problems with her - FASH etc. Typically, when I was away she decided to rev to 2100rpm and then cough and splutter like she wasn't getting enough fuel (I had to drive from devon to Reading at 55mph!) The car is fine when revved up not under load, but just looses all power after 2100rpm when driving - this happens in all gears. a local garage has had a look and say it's definitely an electronic problem. i am taking her to Audi tomorrow which will no doubt cost me a small fortune. Has anyone had this problem before or any suggestions on what it is and how much it will cost me?
Thanks
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Maxi,
This could just be your lucky day,
Electronics? I think not. Have some of this:
www.honestjohn.co.uk/forum/post/index.htm?v=i&t=13...7
Please let us know how you get on.
Oh, and I reckon £150.
Good luck
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Hmm, not as clear as I thought there. A lot of chaff with the wheat.
Your symptoms point to classic wastegate sticking in the turbo.
This is a known "improvement opportunity" with just about every turbo car, petrol and diesel.
Exacerbated by going for a hot thrash then switching the engine straight off without allowing the turbo to coli and be properly lubricated.
£150 to change.
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Sean,
I Enjoy your usually forthright terminology but having a turbo turno diesel Saab myself and therefore your comments having a degree of relevance to my own situation...
...could you please explain what you mean by a 'known improvement opportunity'
With thanks,
IRT
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Hi Ian,
I was going to put "fault" instead of "improvement opportunity" but that is not really the right terminology either.
The turbine in a turbocharger lives in a hostile environment. It spins up to around 30,000 rpm. It gets red hot. Its bearings are a bit weak and feeble, designed on the cost/ benefit analysis of a reasonable price versus reasonable longevity.
The wastegate can be fouled by exhaust gas products condensing and producing oily residues.
Ideally, you would want to remove the turbo and clean and fettle it every 4 years, but they're buried on the average design these days, and most people who remove them get dirt in and ruin the turbine.
An ideal design would have a separate oil feed that kept running the turbo regardless of whether the engine was still running, based on its temperature etc. like some radiator electric cooling fans do, after you've shut down the engine.
All gets expensive.
Sorry, if I've been wordy here.
So, what I mean is, our colleagues Audi garage will now strip his nice (Garrett Air research T3 if i remember) turbo down and fettle the wastegate.
I do hope they won't just change it.
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Sean,
Thank you for your response and understandable explanation.
Not being too technically minded (but not a luddite either),
I asked for advice when I initially purchased my Saab 9.3 TiD and Dynamic Dave provided info including the danger of 'frying' the turbo bearings and allowing the engine to simmer awhile after a spirited run. This I religiously do !
I now understand what you mean by the turbine living in a 'hostile environment'.
Thank you/diolch yn fawr for your wisdom.
Regards,
IRT
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This seems to be costing me a fortune
Audi garage say they have never even heard of the wastegate dump valve and have informed me that they will need to spend another 2 hours on the car (£75.00/hour) looking for the electrical problem. If they do not find a problem then it's definitely the ECU, which COSTS and they can't just put a spare one or a new one on to check it! I am really mad as the car has cost me £300.00 and I still don't know what teh problem is! - saw the Incredible Hulk last night, crap film but I would love to go green and stomp on a few heads at the local Audi dealer
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Maxi,
Look at what I wrote for Ian above. I've tried to describe what the turbocharger does. Think of those little fans you had, as a kid on the beach, then think of 2 of them joined together.
One goes in the exhaust. You will have felt the pressure, even right at the end of the exhaust pipe, n'est-ce pas?
Now then, if we stuck yon fan into this flow, it would spin. If we joined it to a similar one in the induction side, that would spin too, and we could force more air into your engine.
This is why the bearings in both fans are weak and feeble. They would resist the flow at low engine speeds, literally, they are restrictions in the pipework, both induction and exhaust.
Once your engine starts whizzing though, there needs to be governing, like DD and Mark, the Mods on here. This prevents things getting out of hand.
At a preset engine speed, the waste gate opens and excess pressure is just diverted out of the way of the fan (turbine) and up the exhaust pipe as normal.
That is what is wrong with yours, my friend.
That wastegate is stuck and you're not getting the turbo boost you need. It will be carbonised up.
I hoped your garage would strip and clean it, as a new turbo is £400 and they can be cleaned.
If your garage hasn't heard of the wastegate (aka dumpvalve) I'm somewhat concerned.
Print this off, and show them, mate.
Good luck
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sean - I forgot
What you\'re saying about a \'hot thrash\' isn\'t far from the truth - well, I was just about to get rid of the car.......
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sean
Thanks for that, very helpful - i hope ur right on the £150 front - I took it into the local Audi garage this morning who informed that their hourly rate was £75.00 - Thats more than I charge out at and I'm a chartered engineer!
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With the 'hindsight' of a poor performing Peugeot 306 DT last week, I think it would be prudent to check the operation of the Exhaust Gas Recirculation valve on your 80 TDi.....the 306 I looked at last week was slooooow and smoky - disabling the valve (after removing the intercooler and finding it to be choked with soot, confirming my diagnosis) restored the usual spritely performance from the engine.
The EGR valve is on top of the inlet manifold at the top of the engine, easy to see and 'play' with....which is more than can be said about a 406 TD.....
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