Hi  I have a 1.6 Octavia diesel greenline 2010 , the problem i have is that every so often the car starts to be really hesitant won't accelerate jumping about like a kangaroo with blue smoke out of the exhaust, it does not come up with any faults like engine management lights etc and iv'e scanned it and no faults logged. If i blip the accelerator some times it clears and then it's ok or if i switch the engine off and re start it's ok, then it can go for miles before it does it aga