Started my car this morning and drove to work which is 10 miles away and temp gauge was reading 0 all the way. No lights came flashing up and no beeps. Engine coolant is fine and at the right level. once i got to work i parked the car left it running for 10 min and the needle went back up to 90. Did the same on the way home! I changed the coolant temp sensor about a 2 weeks ago as a fault came up, but didnt think that would be the cause as its been 2 weeks since i replaced it and been fine up until now.