I just had an engine builder tell me that my 1998 454 Mag MPI (185 hrs) is "on the way out" because I'm only seeing 20psi of oil pressure w/ 20W-50 at DEAD IDLE after a hard run. I'm using Amsoil Series 2000 20W-50.

Anything above idle and I see 40psi+.

I've always been told my pressure is fine and that the pressure will be lower sometimes with the syn oils. What do you guys think?

Ric,
Those numbers are right where you want them to be. I would put the builders comments in the "premature" category.
Bob

Sounds ok to me......................... I mean wait YES it is garbage you MOST build a 600 HP motor for your boat.

Rag's

I have the same engine and same oil pressure from what I can remember (sorry haven't had it out this season yet) I have 160hrs on mine so we're pretty close. I agree with rmbuilder.....take that advice with a grain of salt.....if your engine is on it's way out I guess mine is also.

I certainly would not take that engine builder any work. Those #'s are fine.

I agree... adequate pressure...

Those pressures are fine for the 454 !!!!!



Any one got data on HP500. Mine stays at about 60 when up and 35 to 40 at idle.

According to the Merc manual that came with my motor (97 454 Mag MPI), Oil pressure can be as low as 8psi at idle. That sounds low but that is what the book says. I think I idle around 20 psi and run about 40 psi above idle.

I wish I had 20 psi at idle hot. Depends a lot on oil temp too. That builder is trying to drum up business, not give you good advice.

I have to agree with your engine builder. That motor has no more than 700-900 hrs left in it.