Got an interesting, and slightly quizzical question. I just noticed that my Temp Gauge was reading Zero even though id been out for a spirited drive.Oh bugger, thinks I, I must have a leak, so I pulled up at home. (Only noticed as I was pulling onto my road) Anyway, turned it off, popped the bonet and no obvious signs of leaks. As the engine was HOT I didn't pop the rad cap off as I didn't fancy a facial.Its raining so i figured id sit in the car and have a fag whilst it cooled down.I flicked the ignition on and the temp started to rise. Turned it over and the temp dropped as soon as the engine was running.Any ideas as to what might be causing it?