Low Oil Pressure With New Motor
 

I've got a brand new 402 stroker motor that we just finished installing into my 2000 C5 Corvette. It's an LS2 block with an Aviad dry sump system. The filter is on a remote mount with a pressure regulator on it.

When we first fire it up cold, it's making 50-60 psi at the factory oil pressure sensor, but once it warms up, it's down to 25-30 psi at idle. We're seeing roughly 10 psi more on a guage installed at the regulator than indicated at the back of the block.

We're unable to adjust it above 30 psi with the regulator at idle once it is warmed up.

Could this be indicative that the barbell or galley plug are missing? Would it be able to make that much psi cold if either of these were missing?

We're thinking we need to go to a different pulley on the dry sump pump but I want to rule out other potential problems first.

Thanks,

Alan

Oil pressure is primarily dependent on your bearing clearances. Chances are your 402ci is set "looser" than the factory settings. Does pressure rise with rpms?

It sounds like bearing clearances, if the barbell was missing you would have close to no oil pressure. How thick of oil are you running?

Thanks for the replies!

Yes, oil pressure rises with RPM.

Oil is Joe Gibbs 15W-50 Break In Oil.

Spoke to my engine builder this morning and he says the barbell was definitely installed.

Looks like we're going to try a smaller pulley on the dry sump pump.

Thanks!

Alan

At what oil temps are you seeing 25-30 psi?

Whoever built/assembled the engine should have a sheet with all the specs and clearances it was set up to on it. I'd check it out first thing and that'll help rule out and/or solidify any assumptions/variables.

Very true, I had the same concern with the LS7 I bought from Jon, turned out I needed to run thicker oil, because of this awesome Florida heat.

I´ve got TPS 402 3K on it and using 10-40w havoline and when i starte the car up cold it is above 40psi 40-50 both cruising and near 40@idel , then when the engine is gone hot around 220F it´s lower or 25-35psi cruising and raises a bit while reving... goes down to 20psi@idel
And if it gets even hotter 250-260F i´m seeing sometimes 14-16psi@idel :confused:

but i´m in Iceland and here is not hot weather it´s cold....:D

so should i use thicker oil, then what oil.....:confused:+

I so hope it´s not bad o ring or similuar to that......


Baezi

Temp??
 

Before I worried about heavier oil, I'd find out why that engine is running at those temps. Cruising @ 220*F is too hot. 250/260*F is insane.
Are you SURE the temp gauge is accurate??
Water or oil temps, either is too high.

sorry about the thread HiJack anybody know what the gm part number is for the barbell my car acts exactly the same and that is what i believe is my problem.

i installed a texas speed 346 in a camaro from day one it only made 25psi at a hot idle.... the motor has been going for 4 years now with zero problems and he sprays the daylights out of it.....

How much oil pressure do you want at an idle anyway? 25-30 psi is more than enough.

Ive always heard 10 psi of pressure per every thousand rpms.

my stock ls2 is 30 psi at idle all warmed up. and goes up to 50 psi when revved

Sorry to revive such an old thread, but we finally determined what the problem was and I wanted to post in case it helps someone else.

The problem was due to the fact that we plumbed the oil cooler into the pressure line instead of the scavenge side of the dry sump system and we were seeing 30-40 psi loss from the cooler.

We bypassed the cooler and now we can get over 80psi at the factory sensor (cold, before adjusting the bypass).