Rough Idle in "S" mode

[DieselTig]

Anyone out there have a similar "problem" with the tiptronic in Tdi where it is set in "S" and stationary, it seems to idle rougher than being in "D".

I have about 9000km on the clock.

Any suggestions?

[NZTiguan]

The only difference I know of would be that in "S" its "preselected" 1st gear where in "D" its "preselected" 2nd. Haven't actually tried it as I very RARELY use "S" and when I do it's never form a standing start, but I'll have a try next time I'm out and see if mine's any different.

Cheers

[Transporter]

It's most likely common to all TDI's auto. More fuel is used when taking off in first gear, that's why it sound rougher (the instantaneous fuel consumption display should confirm that). If you use the "S" mode when not needed your DPF will have to catch more particles and the life of the DPF will be reduced. I would leave it in the "D" unless it is necessary to use "S".

[DieselTig]

Thanks, I only use it on very steep hills, or if when I need to cross a busy road and avoid the syptoms of turbo lag. I only noticed the other day. I will take your advice about the DPF lifespan. Much appreciated.

It's most likely common to all TDI's auto. More fuel is used when taking off in first gear, that's why it sound rougher (the instantaneous fuel consumption display should confirm that). If you use the "S" mode when not needed your DPF will have to catch more particles and the life of the DPF will be reduced. I would leave it in the "D" unless it is necessary to use "S".