LAFNZ06

We just fired a new motor, forged 370, new pump and everything. We first fired the motor, there was 0 oil pressure on the factory gauge. The valve train got quiet almost instantly and we pulled the turbo feed off and there was a solid stream of oil coming out.

We replaced the factory sender and now have pressure, but is low at cold start.

I installed a mechanical pressure gauge at the end of the pressure supply line at the turbo, pressure jumped around at 40psi then dropped to 10psi, quick snap of the throttle and it spiked to 40-50.

oil pressure is only low at start up, sometimes the low oil pressure warning display comes up but is rare, after the engine is warm, about a couple min of driving, oil pressure holds around 40-50 psi, give or take watching the factory gauge.

LAFNZ06

Any one with ideas, I'm about to drop the pan out of this thing to get the pump out

Whiteaw57

iTrader: (2)

did you reuse an old oil pump oring? Did a cam swap once and the oring was visibly fine and I didnt pinch it but when it didnt seal and we got a new one the new one was visibly squishier and fatter. Maybe an old oring is having to get hot and expand before it seals

LAFNZ06

The engine was assembled from the builder, I pulled the pump out last night. Found this SLP pump was not clearances for the double roller chain, the chain hit the pump. When the pump was bolted on, it must have bowed slightly at the pressure port, once the engine got hot, everything expanded and it would sustain decent oil pressure. I have a new pump and chain on the way.

Whiteaw57

iTrader: (2)

awesome, great catch. that could have been alot bigger of a problem

LAFNZ06

Yea on a new motor too, my truck has been sitting for 7 months. Should all good now. Just in time to list it for sale lol.

LAFNZ06

We set the SLP pump side by side, the one on my motor had a noticeable height difference from the mounting bosses outward. We mocked both up on another motor and there was a .050" to .150" difference. Bad pump out of the box, strange...