Octavia mk2 2010 greenline CAYC engine 71000 miles.

 

Any thoughts as to what could be the problem here?, It only happens when the ambient temperature outside is 8 degrees c, the car starts but it is only firing on what seems to be 3 cylinders, engine juddering and a lot of white smoke out of the exhaust, after a few minuets it runs and drives ok. It only happens at that temp any temp above that the car is ok any temp below that the car is ok, I've checked the glow plugs all fine and the power to the glow plugs. Thanks.

   

@Radiogaga Have you managed to check all 4 glow plugs when the issue is manifesting? I suspect you may have one plug that goes open circuit at 8C but only at 8C.

No I haven't checked them at that temp, It does not show any fault codes if one of the glow plugs was o/c at that temp it would come up with fault code don't you think. 

For when lower than 8*oC and to freezing and below,  Is there a nice clean air filter, and air box, and has the Fuel Filter been replaced any time in the past few years.

 

Winter Spec Diesel even in the south now being sold, so if the old Summer Spec is in the tank time to fill the tank before really low temperatures, 

but they would need to be more than minus 8*oC and much lower.

@Radiogaga is the coolant level in the expansion tank falling?

All the filters were changed and the oil by me in May, didn't know they sold winter spec diesel first I have heard of it, will look into that.

 

As to the coolant no it is not falling I have checked for that, oil in the water, water in oil no mayonnaise under the oil filler cap.

Never had a problem in the summer and the other week when the temp was at zero no problem then, it was doing it last winter as well, but as the weather got warmer and it wasn't doing it I forgot about it TBH. 

Winter diesel is anti-waxing and starts getting delivered in Scotland and the North of England from mid to late October then further south and until the end of March.