Congrats on figuring out your gauge issue.
Idling for an hour is longer than I have ever let my F250 sit running for.
Since the oil is leaking from your v-band and the HE351 you are running was used, I think it's a fair guess that maybe the thrust bearings are worn. How much shaft play does the turbo have when cold?
No leaks at all from the engine and no oil from the vent tube on the drivers side. My oil drip is showing up at the exhaust downpipe V-band clamp on the turbo. After idling an hour or so there are 2 or 3 drops on the driveway. Turbo is a used HE351 I bought. Don't really know any history about it.
Idling for an hour is longer than I have ever let my F250 sit running for.
Since the oil is leaking from your v-band and the HE351 you are running was used, I think it's a fair guess that maybe the thrust bearings are worn. How much shaft play does the turbo have when cold?