Hey friends,

 

Post Stage 1 ECU/DSG remap and 150 km, my 2010 MkII Superb 1.8 TSI DSG is running very rough. Lots of vibrations, jerking motion, lack of power makes it undrivable below 2500 rpm. Problem started immediately after I floored the accelerator and let go of throttle, I think I blew a coil but not sure. It looks and feels like a misfire but there is no check engine light and VCDS shows no misfire faults.

 

Video of exhaust sound:

 

Video of engine vibrations: 

 

 

Appreciate your help in troubleshooting this.

Edited 26 September, 20187 yr by Lightbringer

@Lightbringer - Did you ask the tuning company about the issue (or was the tuning a DIY)? What is the increase in HP (or percentage)? For the glow plugs to give up by a simple accelerator push, you would be looking at a Stage 2 or even Stage 3 before that should  happen. I think the easiest way to debug this would be to revert to the stock map and see how the car drives/runs. If the engine would be running normally, the tuning was a bust, if it wouldn't, you can proceed checking the mechanics further. For every good remap, a proper working engine, and all the other important components, is a must.

@vborovic I asked my tuner and he drove 100 km one way to come and troubleshoot the issue (for which I'm very grateful). He says its a coil problem after changing the coils around (& looking at the vibration of the engine- I don't quite agree with this technique so would appreciate your valuable opinions) and recommended me to change/upgrade all 4 coils and spark plugs. He also told me my stock coils (06H 905 115) were known to be problematic. I then googled it and sure enough VW recalled that back in 2010 for some GTIs but unfortunately Skoda has issued no recalls for my vehicle. I doubt its his map, his first map had some small issues (mainly with the DSG tune) but he promptly gave me a second map and it ran perfect for 150 km. I did a test run one night, measured VCDS acceleration (got 0-100 kph in 7.4s in drive and sports mode, DSG was very smooth) and even told him the map was very good (still have to pay for the DSG map). But next morning I went for a drive, floored it in an empty stretch, eased my foot off and then the vibrations began at low rpm/idle. Its not completely smooth at higher revs but relatively smoother and my mileage reduced to 2-3 km/liter.

 

What completely throws me off is this does look and feel like a bad plug/coil issue but at the same time VCDS gives no indication that there's a misfire or anything wrong with the coil/plug. I don't want to spend money on new coils and plugs only to find out its something else.

Friends, it was the ignition coil alright. Changed it and the engine's running smooth as ever. Whew!

Faulty coil (looking at the service history, one of them had failed while the car was stock): 06H 905 115

I changed to a febi coil now, Skoda service center put in VAG 07K 905 715 G when it failed before.

 

I still don't get how my Skoda which finds and logs even a faulty bulb couldn't log misfires or faulty ignition coils.

This is kind of like a good news, bad news situation ... the three others might fail within a few days, because the stress will transfer to them now ... at least you'll know what to change if you get the same symptoms ...