I have a 2017 Duramax about 70% of the time I pull the dipstick the oil is about 2 inches above the full mark. If I leave the dipstick out for a couple minutes then put it back in it reads in the normal range. It does this even if it sets overnight. What would be causing this to happen. It has only been doing this sense the last oil change I use Amsoil signature diesel oil and the Amsoil filter. TIA