2015 Audi S3 misfiring / stuttering at high RPM

[adamm]

Hi everyone, I would appreciate some help from the vast knowledge on this forum!

I have a 2015 Audi S3, 102K miles on the clock.

Misfiring / stuttering was first experienced approximately 5 minutes into a journey. I had been driving slowly at 30 mph, then put my foot down and felt a misfire / stutter - I think at 4000 / 5000 rpm. I quickly backed off, drove for a few minutes at 2000 rpm, then put my foot down again (for a bit longer this time, a few seconds) and the car misfired / stuttered as before. The EPC light also came on.

Someone at work has a machine to read error codes so we plugged it in and it pointed to a problem with cylinder 3. Whipped out the spark plug and found the gap was (much!) too big, more than 1.0 mm. Gapped that plug and ordered some new plugs. I drove the car in Eco mode for a few days whilst waiting for plugs and it seemed to be fine.

When the new sparks plugs arrived I decided to test the fault. As soon as the revs got high the engine misfired / stuttered again, EPC light came on, lost a LOT of power, and could barely pull away from traffic lights (I was able to manage maybe 15 mph). Pulled over, turned the engine off, waited for a few minutes, started it up again and it was fine (I drove home very carefully!).

Checked the error code again, pointed to cylinder 3 again, which made me think it could be a coil or injector problem? Or perhaps spark plug was completely knackered?

All spark plugs are not changed and took it for a quick spin and did not misfire / stutter at 5000 rpm. I'm still nervous about driving it though in case I cause lasting damage... does anyone have any advice on:

1. whether the error was likely to have been spark plugs?
2. why the car would react different each time, with: no EPC light, then EPC light, then "very low power"?
3. whether, if the car start mis-firing when I drive it, it's ok to drive in Eco mode at low revs (no issues so far) whilst I wait for 3 weeks (!!) for the local injector specialist to have a look at it?

Help greatly appreciated!

[futtret]

had very similar issue on my 2015 A3 2.0 TDI
Error code was P13D600
The glow plug in cylinder 3 has a pressure or temperature sensor built into the glow plug.
Changed that, all is fine
(apart from my heating not working now, probably unconnected issue)

[Crasher]

had very similar issue on my 2015 A3 2.0 TDI(apart from my heating not working now, probably unconnected issue)

That will be the annual MQB platform blocked matrix... again. Two in last week and one in tomorrow.