T5 bi turbo high idle and not quite right.

[Steve72]

Hi, I have a T5 bi turbo van.
Since day one it has had a few issues.
The main problem was for no reason at any given time to engine would start to idle just above 1000rpm, at this time I could notice the engine not running like it usually would, not much different but definitely not right.
Sometimes at this stage it would start surging as I changed up through the gears . Some of the time it was more severe than other times.
Then as quickly as it began it would go back to normal running, smooth and a pleasure to drive.
After many visits to the dealer and lots of my time all I was told is that there are no faults coming up and everything was ok.
After almost 12 months of this I emailed VW Australia and was given a case manager who was very helpful.
A couple more visits to the dealer and more of my time fially a software update was done.
This definitely helped, the surging has totally gone away, however the idle still goes just over 1000rpm from time to time and engine is slightly flat. As before it goes back to normal running after a while.
It probably does this between one and five times a week.

Also during this time a solenoid valve failed on one of the turbos, this had a major effect on the running of the motor but was probably unrelated.

I would be interested to hear anyone's thoughts on this.

Thanks
Steve.

[Cousin]

Steve, first thing that comes to mind is a regen for the diesel particulate filter
That is, at certain intervals engine management starts a regeneration process to purge some of the soot accumulating in the dpf
My van is pre dpf, so I can't speak from experience, but some of your symptoms sound similar to what others have mentioned
See what other ideas come up


M