[bugsiegel]

Mike
I'm certainly no expert in here but I had a similar situation. Fresh rebuild with similar numbers with the original factory sender unit. I installed an aftermarket gauge and the readings were then 55 at start up and a little lower after a some driving. So the sender unit was bad. I replaced the sender unit to the factory gauge and then split the line to run both gauges. They now read the same but the factory gauge will come up about 1 second faster (being electric) than the aftermarket gauge.
Check your sender/gauge.