Driving to work the other morning at silly o'clock 04:30, everything was running fine. Temp gauge ok, nil warning lights. The header tank light suddenly illuminated, after a few mins went out.
This on / off happened 3 times, but engine temp stayed a constant. Thought it could be a dirty sensor.
Checked on arrival at work...............to my horror the header tank cap was missing!!!!!!!!!, fortunately it had lodged itself inside the engine bay.
I had checked the consumable levels the day before, but in my haste had not double checked any replacement of caps etc...............very lucky & got away with it...........