My x type jag wont restart after its been running for 5 mins onwards. It takes at least 5 or 6 attempts before it kicks in. Also the water in the system has run out completely over the last few weeks on a couple of occasions with no apparent leaks anywhere. Im wondering if maybe the cylinder head gasket has gone ? Any feedback would be very grateful. I am about to put the car into an independent jag dealer in the next day or so to hopefully solve the problem. By the way the car drives well otherwise.