Hello Scotty, just like to say thank you so much for your channel, I have saved a fortune fixing my car myself :).

My question is, my missus has a 06 renault megane 1.5 DCI diesel. When starting the car it seems a bit grumpy (shakes) and blows out white smoke. However, the car drives fine after a minute or two. There is a warning on the dash to 'check injection' - the injectors seem to be ok... any help would be great! Thank you :).

well, injectors throwing too much fuel in will make em smoke white. Pray it's not a blowing head gasket which this video can test https://www.youtube.com/watch?v=QA7KVQq9vKA