This morning I noticed my car's temperature was going up and then suddenly it went down. I usually dont drive long distance, but today I did, and I noticed that after it reached the middle point of the gauge that it began to fall and then raise again. I was wondering if this was normal? Or should it be at half point when the car is fully warmed up? I did check the motor oil after I parked it for a bit. And it seemed normal to me.