oil pressure

[nu2gn]

so i finished my engine, primed it, timed it. started the car, i had 45-50 psi at 2500 rpms, kept it running for 20-25 for cam break-in, now hot oil pressure is at almost zero. the oil light is not coming on, any ideas? can someone tell me what oil pressure each of the oil pressure springs are?

 

[nu2gn]

forgot to mention that crank was ground down to 20/20, camshaft was replaced with new bearings, rod and mains also. replaced lifters, front cover and gears. i'm ready to call it quits.

 

[mikestertwo]

Your problem isn't the pump pressure relief spring. Changing it won't make a difference. Sounds like you have too much bearing clearances, pump clearances, or you have a leak somewhere.

 

[nu2gn]

i just don't have the time and motivation to mess with this anymore, i'm at a point where i want to get rid of the car and just buy a used mercedes e55 kompressor and have 470 hp from factory, but i've always wanted an gn with hopes of keeping it and pass it down to my son.

 

[turbo nasty]

What weight oil?
What spring in the oil pump?
What temp is the engine when you think the psi is low?
When you rev it does it come up for 10 psi per 1ooo rpm or better?

 

[nu2gn]

i used 10w30, with pressure goes higher than ten psi when at 1000 rpms, i am pretty sure that i used the white spring, also used zinc additive

 

[Dabigguy]

You need at least 10psi at idle plus an additional 10psi per 1000 rpm.....4000rpm=50psi

 

[TurboBuRick]

I would verify with another (analog) gauge.

If pressure is dropping to 0 at idle, time to pull the pan and inspect a few bearings. Like mentioned, it sounds like excessive clearance for one reason or another.

Don't run it hard until you know whats going on.

 

[nu2gn]

going to get another gauge tomorrow to verify that there is not a problem with the gauge

 

[Turbo6Smackdown]

i just don't have the time and motivation to mess with this anymore, i'm at a point where i want to get rid of the car and just buy a used mercedes e55 kompressor and have 470 hp from factory, but i've always wanted an gn with hopes of keeping it and pass it down to my son.

Well the mercedes is about 30,000 used for a 50,000 or so mile example. Now, tell me what your insurance is going to be for that gem. Anndd, tell me what a new starter, or new window motor will cost. Oh yea, and don't take it to get an oil change. Even at a local place, it'll be twice what you normally pay.
All for what? Stick with it man, no car is perfect. An American classic is ALWAYS better than some foreign car.
Think of it this way. I could buy a 10,000 dollar grand national, put 10 into it, & have a car that would beat the BALLS off of that mercedes. AND have ten grand left over
When on the streets, that kompressor is just another ride. Sure it is a sweet car, no doubt. But when you're lining up with someone, the Grand National will not only get a triple take, but make the driver of the other car think real hard before considering. Trust me. When I was hunting on the streets, I couldn't buy a race to save my life... Cuz they knew about the black buick.... Everyone knows to watch their P's & Q's around us. Everyone.

 

[nu2gn]

thanks for the advise man. u got me sold, i will give the gn another chance. i'm going to drain oil and check oil pan and hopefully check rods and mains for clearances. o yeah by the way, the only reason why i mentioned the e55 is because i have been a mercedes-benz certified technician for 8 years. and i wouldn't mind having one, but the gn is better at turning heads. thanks again

 

[Tom Tom Turbo]

don't give up on this thing....I have been chasing low oil pressure for a few months and it ended up being a high volume front cover that kept pushing the gasket out due to poor machining.

my new motor would only idle around 10 psi but at a cruising 55 it would pull about 42-45

 

[Turbo6Smackdown]

Workin on our cars can be tricky. Sure. But they're usually simple though. TRUST me, when she's all dialed in, it will feel soo much better. And they're SOO fast too. Once you stab that throttle, you'll be hooked, I guarantee it.

 

[turbofabricator]

Try cutting the filter apart to see if you lost a bearing, FIRST. If no debris in filter, then check the oil pump, and then oil gallery plugs in the front of the block. THey can pop out if not staked in correctly. Then you may have used .010 undersized bearings instead of .020". What was the bearing clearances on rod and main bearings? They need to be .002" or LESS. I shoot for .0018" on both rod and mains. Then look at cam bearing issues. If the timing cover is an aftermarket unit, I would start there first. (after cutting the filter apart to look for a dead bearing.) Keep the timing cover oil pump cover clearance to less than .002". (.0005"-.0015")