As well as some other oxygen sensor faults to do with the car running too rich, we've been getting the red coolant level or temp light coming on asking us to pull over. Happens intermittently, small trip or long. The car isn't low on coolant or showing anything but normal temp on dash gauge, (Has been to auto electrician, who have been sorting the other faults, but the coolant warning doesn't seem to be saving, they can't see anything logged. When it has happened, after leaving for 5 mins, the car drives fine without the warning light coming back on. Anyone have any idea's or had this experience and got to bottom of it. The car has done 170,000k's. Has just had pretty dirty spark plugs replaced by auto electrician who was trying to sort running rich issue.