2000 f 250 7.3 The oil gauge does not move for about 2 seconds after starting, the goes back to normal

Nothing too unusual... synthetic oil?

Engines with full synthetic HDDO build oil pressure 7 times faster than conventional oil. This should help with this problem. Conventional oil, anyhow, is the kiss of death for turbos. I wouldn't use it in a diesel, even if you gave it to me. This link should help:

https://www.askmehelpdesk.com/cars-t...ml#post1415281