Just rebuilt a D15B that i picked up for cheap, the guy said it ran fine but i dont like taking chances so i rebuilt it anyway. good job i did cause it was starting to wipe out the bearing, my guess is low oil pressure. Turned the crank, new bearings, new Melling oil pump, everything was plastigauged and checked. All checked good.
installed the motor in the car and with a manual gauge I have 25-30 psi at idle but as soon as I raise the RPM's the pressure drops to about 10-15 psi. I called Melling and they sent me another pump. I shimmed it first then installed it. I had 60 psi cold at idle but as soon as it warms up it drops to about 15-20 as soon as I raise RPM's again. I'm new to the D15B but I didn't see any squirters or any other reason for low oil pressure when rebuilding. Any help or suggestions would be greatly appreciated. Thx.

 

I did a bunch of research online and ended up using Clevite bearings. The machine shop that turned the crank told me it used 1.5 main bearing and 1.6 rod bearings so as per them that's what i put in but everything plastigauged good, right in the middle of the specs as per ALL DATA. as for oil pump, its a Melling 1178 i believe, but would have to check for sure.

 

15-20 at idle warm is fine but does it still drop when hitting the gas with the new pump?

 

yeah i was driving and holding a constant 4000 rpms and it stayed at a constant 15-20 even when I stopped at a light. no change

 

very unlikley but bad gauge ...

 

Does anyone know if the jdm D15b is supposed to have a oi orifice restrictor between the head and block. I justed pulled the head ok and this motor does not.

 

^^^No it doesnt

 

i'd try pulling the oil pick-up and cleaning it out.