A weird thing happened yesterday with regards to the temp sensor on the instrument panel. It suddenly started flickering all over the place and then stopped working all together! It now shows 0 all the time and sometimes it will start flickering then work for a few minutes then stop again, I presume its and earth fault but have no idea how to resolve it, i am also worried could the engine overheat when it shouldn't now? can anyone please help, its a '88 260e w124.