I have just purchased a June 2009 Focus ST 2, 100,000 miles but full service history and obviously very well looked after. The car drives perfectly and I have done almost 1000 totally trouble free miles with no issues and all the gauges reading normal. However starting from cold on a morning there is a significant amount of white / grey smoke which clears after about ten seconds and then no sign, however there is a smaller amount of smoke even if left for half an hour or more. A mechanic has said head gasket but I have a feeling it could be more related to the fuel injection. Any ideas gratefully received