Intermittent light blue/grey exhaust smoke - 2009 Passat B6 Estate 20.L tdi Highline Plus

[davies63]

Hi all,

for a little while now, my car has had an intermittent exhaust smoke issue.

For 5-6 days, the issue won't be there but then, for a day or two, it'll have light blue/grey smoke from the exhaust. Whilst it's 'smoky':

o The exhaust smoke only appears after a few miles of each journey and is always preceded (by around 1 minute) by an exhaust fume smell in the cockpit
o It happens every journey
o If I pull over, stop and turn the engine off, it soft resets but will come back after the aforementioned few miles
o It only happens under acceleration and not whilst maintaining a constant speed
o It's much worse in lower gears
o There is no drop-off in response or MPG when it happens
o When it's not smoky, there's not even a hint of it, smell-wise or visibly

The only direct correlation in anything I have noticed is that, whilst it's in a smoky period, idle speed increases to 1000 rpm (from around 800rpm normally).

Thanks in advance and hope,
Kim