I've got a 2006 td4 auto. A few times I've driven it, turned ignition off and if I've tried to start it within 10 mins it won't start. It makes all the right noises but just won't start. It starts fine if I leave it and come back later. No engine lights on or anything but I think it's trying to tell me something. Any ideas what it might be before I take it to garage? Thanks.