Turned the key to start the engine but instead of immediately purring in to life, there seemed to be a second or two of knocking (like exhaust hitting the body or loose/worn engine mount) or something. I switched off and tried again twice, both times it happened again. I decided to drive on home and everything felt and sounded normal. When I arrived home I turned off engine again and restarted but was okay, no knocking or anything. It's never happened before, anyone experience this before? Perhaps some guidance on what to look out for?

 

Andy

Edited 3 November, 201510 yr by Hightower79

It is a funny time of year for car engines. The oil companies change the formulation of fuel so that cars run OK in cold weather. BUT today (here in Norfolk) the temperature was 16 so it is too warm to require the cold weather fuel. Now diesel engines when cold struggle to idle smoothly. The compression ratio of a turbo charged engine barely produces a high enough temperature to burn the fuel. So the engine idles badly till it is warm. My car (also 1.6 diesel) stalls readily when puling away with a cold engine and needs more revs to avoid this. When it is warm it can almost pull away with no throttle.

 

In a few weeks with colder weather the fuel mix will be for cold weather and the car should idle better when cold. Bad idling with a warm engine is another thing completely and may be a problem or a DPF regen.