bit of an update but not much lol, oredered a coolant temp sensor, i dont think that is the prob but at 22 quid got to try it first, i serviced the car the other day, new oil and filter and fuel filter and the problem still happend the next time i started it, but since then its stopped, the car seems totally fine,i thought maybe fuel filter was blocked but the fuel seemed clear and i always change it when doing the service maybe leaon you could try a new fuel filter and see if anything changes just to test