ApplagApp Forum

Hi all!

Hopefully there is someone here that have experience and could help me.
My car is atm either starting , engine shaking and directly shutting off or it remains running but with practicslly no power at all. The car is an Audi A4 2.0 TDI with 180 000 km. Only known long time issue is increasing oil consumption (no visible leaks) during last couple of years.

So some background info. Maybe two months ago, first issue waa sudden error code about EGR low flow. It came and went away sporadically, then never came back again. During the same period the car started consuming much more fuel, and also started showing psrticulate warning light (which went off after driving as well ). This has since been sporadic but returning, however the last two weeks the car got noticeably more powerless and suddenly one trip started to turn on a bkinking warning light (glow plugs?) and lost like all power, together woth new errorcode turbo charger underboost. It happened almost every accelerarion after that.

Now i installed the DPF VAG app after searching info about the DPF warning initially, and noticed the following behaviour. The car seems to fo active regenerations like every 5-10km after it finishes one (from 100% to about 10%, anf 5-6g soot), the measured soot value rises from idle when driving normally to 25 and then the app sounds again (the calcukated value is low but jumps up). Also the differential pressure is from start att 300-500 on idle valur and while driving around 1000.
Finally the ash value is showing 0.13 l (not gram?)

What if anything can be said and suspected by all this?

It seems a complicated issue.
What I can tell you is to don't fully trust on what your read from the app because those values can be altered by the ECU, if needed.
For example the sudden jump of the soot mass is the common clue of the ECU management: it can force the soot mass filling to 100% to immediately start the regeneration process, this can happen when you reach the maximum time or mileage limit between regenerations, or when there's a sensor fault. Or also for any other unexpected value that the ECU detects. Unfortunately we don't have the full specs of the DPF system, hence many evaluations are based on experience on the field shared by users, not on a real technical documentation.

Did you already visited a service center or maybe planned to go to? An experienced engineer has probably a more reliable answer for you than what the web can provide.
Sometime a simple sensor failure may create a big issue, only because the ECU can't be sure about what's really happening in the system, and for safety reasons it forces frequently regenerations to avoid the risk of fire. Replacing the sensor fixes the issue with few euro. I hope this is you case.