Hello. My coolant temp sensor started to go eratic around a week now. As the coolant was due to get replaced, I got a new sensor. I replaced it as I replaced the coolant. when I was making sure there was no airlocks with the expansion cap removed, the guage rose steadily to 90 degrees and didnt exceed. I was waiting for the fan to go and off to complete the anti airlock proceedure, it never came on at all. Can this be because the new coolant temperature sensor is doing its job and not letting the temperature exceed or is there a fault with the fan?.

It's not really warm enough outside at this time of year for the fan to need to come on, unless you'd just been for a motorway thrash for half an hour, then sat idling. even then it might not.

thanks wino, thats put my mind at ease. after the day I had, dropping the sensor clip deep into the engine. I got it in the end after a few chosen unpleasant words.

I also noticed as well that the coolant level dropped below the minimum. I topped up to the Maximum line. now after I'd finished there was more coolant in the tank about an inch above the maximum, should I remove this excess?

Take it for a fifteen or twenty minute drive tomorrow and then re-check, you may find you don't need to take much out after that.

Thanks again Wino. All the best

just checked the level this morning, its dead on maximum. however, a 16556 fuel mixture too rich bank 1 has come up with no lights on the dash. should I be worried?

Wait and monitor. It may just be the engine ECU confused by the new, correct, temperature data; in which case it will go away on its own in due course.