2,5 tdi AKE running rough when warm.

[bluezie]

Just noticed this" I reread the thread yesterday" Wow! this thread is longer than the holy bible !!?? The car is an 2001.
I couldn't care less about the past of this car, but I'm seriously concidering it,s future -and - no, switching the engine is not cheating, it just looks that way

Well no , not exactly cheating, but seeing as MOT failures are now available really cheaply, it just makes sense to get to the bottom of this really quickly by swapping parts from a known good car. Normally VCDS is the window into these cars, but if it's not showing anything definitive, perhaps the 'parts swap' procedure is the way to go? Personally I hate this method, but in this case, maybe the most cost effective............

[ametlib]

Wifey just remind me about another funny sympthom with this car , The car have a webasto with remote, it will run for half an hour if you start it, Funny thing is if you run the webasto anything between 5 and 20 min. the engine will not start !
No matter what it will run down the battery, no start! This even happened today with a temp at around 8 C. The car will start fine without running the webasto or if you run it full time (30 min)

[sjordet]

That's not unique to your car I have just a normal water-heater, but after just 10 minutes of using it, the car will not glow for even a second. If it's cold, it's not going to start before I have maybe atleast an hour of heating... Or ofcourse not using it at all. Then it always starts, even at -30 degrees celsius

[ametlib]

You're ofcourse right, and its at least partly about where they placed the G62 sensor. And yes, also right about the lack of glowing, but it will not start, even in + 10 C .... and, really ,it should ....

BTW After just been watching Leonardo Di Caprio make a speech in UN, I got a feeling that all of our oilburners soon will be historie anyway

[nedge2k]

Just to update my issue - long story but i had a major pre-turbo exhaust leak causing the major lack of boost. I've since fixed it and adjusted the actuator so that you can just about get a feeler gauge between the arm and the stop. The spec and actual MAP now match from about 1800RPM - which is still not ideal but at least she's drivable again. Below 1800RPM when warm, the bark is still there (obviously) and above 2000RPM when cold I also get a bark.

My turbo is VERY whistley up until about 2500RPM so I may have a slightly blocked exhaust - turbo itself has no (or very little) play in the shaft and no damage to the in/ex blades, VNT is smooth.

So more work to do but probably not until next spring/summer - got other projects to sort out!

[ametlib]

Thanks for posting back .
Yours have pretty much the same sympthoms as mine, exept for the spec. and act. boost read by the ECU/ MAP. On mine there is a slow spool up the first two minutes after start ( witch is normal in cold weather), but after that the act. matches the spec. boost pretty good.
Can you explain what " a feeler gauge between the arm and the stop" means ?
Where exacly was the exhaust leak ?
I'm starting to wonder if it's time to take a look on the exhaust parts placed before the turbo?, thinking more like blockage rather than a leak

[nedge2k]

My exhaust leak was caused by me

Basically, after rebuilding the heads, when putting everything back together, I couldn't find the gaskets that i thought went between the intermediate pipes and the turbo collector. As it turns out, I couldn't find them because they don't exist! However, thinking I knew better, I made some gaskets...not long after, they failed and that's what the hissing noise was, not the actuator. See: 2.5 TDi Intermediate Pipes to Turbo: Gasket? | Audi-Sport.net

Regarding the feeler guage, I adjusted the actuator arm so that it stops just short of the physical stop screw (so there is a very, very small gap).

I think I might adjust the stop screw to try and get it spooling up earlier.

[adamss24]

You will cook the turbo if you adjust the stop screw, don't touch it ! If you need to you can shorten the actuator but don't touch the stop screw unless you have a EGT/EMP gauge.

[nedge2k]

In your experience, do all the factory adjusted turbos have yellow paint on the screw? (mine does)

[nedge2k]

Forgot to say, I've not logged this yet but once the engine has been hot for a long time (e.g. a good 30min drive), the bark drops from 1800RPM to under 1500RPM. I know the diesel temp. is monitored, maybe that has an effect too?