??? Possible Oil Pump Issue ???

[TimTurboZ]

When recently preparing to start my freshly rebuilt rb25, I cranked it over after removing the the oil return hose (to oil pan) to check for proper oiling thru the turbo and I got nothing...I cranked it in intervals and then longer periods and nothing. I'm unsure if it will build enough pressure this way or if it may need to start up, but I was under the impression if I cranked it by hand it would flow oil thru all lines.

I've never started a rebuilt motor and I don't want to risk damaging anything if it's not lubricating things properly.

Is there a way you know of or a procedure you follow for checking this out? When I started my 5.0 motor I had a oil pump primer rod but thats a whole different motor design not sure what an equivalent would be if there is one to primer my system.

Sorry if this make me seem like quite a noob but I just expected to see oil

Thanks Tim

[boostedh23a1]

I would just crank it and shut it off. Being a fresh rebuild you should have all that assembly lube on everything. My N1 pump shattered in my shops lot and i cranked it and drove it on the rack and it was still fine. When i put a new Tomei pump on it took a second or 2 to get oil pressure initially.

[robbie2883]

^^NO! do not just start it up. the first few seconds of a motors life are the most important and there's a big difference between 250 rpms and 1000. pull the fuel pump fuse and have someone watch the oil line. ( i typically pull the oil feed line for the turbo but return should work too. turn the car over with the starter (it'll only fire at around 200-250 rpms with no cylinder pressure) do that in 4-5 second intervals until oil starts pouring out. and it will POUR out.


won't help you now but another note is when you're assembling the motor, you can prime the oil pump buy packing a bunch of grease into the oil pick up on the pump (not the pickup tube but the pickup after the tube directly on the pump) this will create a heavy vacuum when first starting up and helps get oil flowing.

[Darius]

You should have used assembly lube on everything and oiled the cylinders before you put them in. Also with the turbo, you should have dumped some oil in the center housing to lube the bearing. I'd start it up and monitor an oil return if you don't have a pressure gauge. If it doesn't generate pressure within the first 5 seconds of running, then shut it off and re-evaluate the situation.

If you are really worried about it, pull the plugs, disconnect the fuel injector harness and crank it until oil comes out of the oil return. This will put less pressure on the bearings while turning the crank in case there is something wrong with the pump.

[julio]

After my rebuild, it probably took 1-2 minutes worth of cranking (not running!) for oil pressure to reach the feed line. I didn't pack the oil pump, but my center cartridge was full of assembly lube from its own rebuild.

[Darius]

1-2 minutes of cranking?! Did you have an external oil cooler or something?

[boostedh23a1]

oops seconds... hahaha. you should see some oil pressure on the starter alone... maybe 7-8 pounds.

[TimTurboZ]

Well I did it for about 5 seconds in MANY spurts, and then about 10-15seconds (I had no power to my fuel pump and I disconnected my injector and coilpack harness so definitely no issues there. Should I remove my sparkplugs? (less pressure on the rings?) I had an Optima battery in the car and it cranked quite easily/fast.

The motor was hot tanked so oil galleys should be cleaned out, the turbo oil lines are from my rb20 which was running so they should be free flowing, the turbo I am unsure of I guess I could remove the oil feed line and see if I see an oil, but seems odd for the oil to be restricted by the internals of the turbo.

[robbie2883]

it takes awhile on a new motor...you'll be surprised. i wouldn't worry about pulling the plugs...the normal compression pressure isn't going to hurt anything.

[TimTurboZ]

it takes awhile on a new motor...you'll be surprised. i wouldn't worry about pulling the plugs...the normal compression pressure isn't going to hurt anything.

Just discouraging cranking it so much and seeing no oil. Guess I'll give it a shot when I get my harness back next week (having my harness wired by a shop since I fried my ECU)

Is there any better way to check my oil pump for functionality?

[gawdzilla]

If you're super paranoid you can try filling your motor with oil from the bottom. I had an accusump sandwich fitting laying around that I attached some barbed hoses to and pumped in about 3-4 quarts of oil using a drill driven screw pump through the motor before I even turned it over with the starter. I didn't pack my oil pump so I was a bit scared of not having enough assembly lube/oil on everything. The screw pump alone gave me about 10 psi of pressure according to my gauge.

[240z4u]

If you do pull the plugs, the engine will crank faster and it won't be so hard on your starter. I had to crank my subaru for what seemed like an eternity to get oil pressure after I rebuilt the engine.