what is your oil pressure? If it is low (2-10psi after a hard pull) and you have not added the performance mods, you could have a spun bearing.

guage is off

I has the same problem in one of my motors. Everything else was fine (water pressure and temp, oil pressure, etc.). I took the oil pump and cooling assembly apart and a few of the channels were plugged with a tiny amount of debris (probably off the old filter). I cleaned that out and it's fine. It didn't look like enough to do anything but it was. Everyone was telling me the guage was off (including Merc master mechanics) but I could smell hot oil in the bilge.

Had