Freshly rebuilt engine won´t build oil pressure?

[doublins]

So... I got my engine back from the shop last tuesday- it´s freshly built, all new bearings/new cam.

Dropped it in yesterday- put 6 qts of brad penn break in sae 30w in, primed the oil pump for 2 mins with an old distributor shaft and my drill, installed distributor, and fired her up- started on the very first crank. Immediately brought engine rpm up to 1800 for breakin- Ran for 30 seconds before I noticed oil pressure was VERY low, as in barely at the 20psi mark on the gauge- Shut it down, pulled the distributor, and had my g/f watch the gauge in the car while I hit the oil pump again with my drill, at max speed of 2700 drill rpm (which would equate to an engine speed of 5400rpm), oil pressure will not go higher than 20psi on the gauge!

I bought a replacement oil pressure sensor, swapped it in, and same thing, so it´s not the sensor-

What do I do? I´m afraid to start the thing now- this oil pressure is WAY too low.

I´ll call the machine shop when they open tomorrow, guessing I have to pull the pan and check the pickup/pump assembly... but what on earth could be causing this? I would expect at cold startup with a straight 30w break in oil the pressure would be closer to 80psi, not 20

Help!

-Chris

[Cheromaniac]

Check that the oil pump to block mating surfaces are flat and that the pump is snugly bolted to the block. I have a feeling that you might be losing oil pressure in that area.

[Retlaw01XJ]

That would be my first guess as well. Some blocks have a high spot at one end of the oil pump mounting pad. There's often enough play in the bolt holes so you can move the pump a little and get it off that high spot.
I believe there are pics on this site showing this.

My second guess would be the oil gallery plugs are loose. There's one at the front of the block, and one at the rear.

[doublins]

Well, it´s the same block/pump that was in the stroker before I had the valvetrain debacle that led to the rebuild- I installed the oil pump and pan the first go-around and always had perfect oil pressure. This time I had the shop put all the sheetmetal on the engine and deliver it to me ready to drop in- I wouldn´t expect a clearance issue with the same block & pump since there wasn´t one last time, right?

Even still, I guess we´ll find out one way or the other because the only logical thing to do next is pull the pan and start looking around.

If it´s a galley plug, if the rear one is loose, then oil would be leaking out through the bell housing, right? If the front one is loose, I have to pull the timing cover I´m guessing?

-Chris

[SilverXJ]

Check here on checking the pump to block interface: http://www.jeepstrokers.com/forum/viewt ... =34&t=2671

Also, check the relief valve in the pump, the pickup to pump fit, and pan to pick up clearance. On the galley plugs it would be the front one if it was out. The rear would puke oil all over the floor.

[Muad'Dib]

I had a similar issue on a rebuild i did and the culprit was #1 Main bearing cap installed backwards. Just a random thought.

[doublins]

So.... I was thinking, and this is something I can´t verify until this afternoon because I´m at work, but I have been pounding my head over where the hell I could be losing oil pressure....

Then I had an idea... I was priming the oil pump with an old distributor shaft that I stuck in my 1/2 dewalt corded drill.... BUT I did not install a distributor body in the slot; I only ran the shaft down to the pump with nothing filling the distributor body hole- is there an oil passage for the dizzy that the body normally plugs up? And without a distributor body in place, could this explain why I can´t build oil pressure?

Anyone know?

[SilverXJ]

Nope, its not a Chevy.

[doublins]

Nope, its not a Chevy.

Damnit, back to square one

[doublins]

Well, I pulled the pan, pump clearance looks fine- after work today I guess I will dip the pickup into a bowl of oil and run the pump again, and see if the oil is puking into the timing cover to check if the front galley plug is missing.

[doublins]

Found the culprit... No front oil galley plug

[cruiser54]

That's bittersweet. Good thing that's all it is, but it sucks you gotta deal with it.

[doublins]

Yeah... the euphoria of getting everything back in, wired up, all fluids filled, ready to break in, and then realizing you have to break it down again really sucks...

If you've never pulled a timing cover with the engine still in the vehicle, it's a pain in the nuts.

I just hope the 30secs to a minute I ran the thing without the front oil plug didn't do any damage.

Sigh.

This didn't happen last time when I put the plugs and covers on myself... I figured this time around I'd let the machine shop do all the assembly. If you want something done right...

[SilverXJ]

Pulling the timing cover with the engine still in isn't that bad. Luckily you found the leak. I would have a word with the machine shop.

[doublins]

Pulling the timing cover with the engine still in isn't that bad. Luckily you found the leak. I would have a word with the machine shop.

I had to drain coolant and pull the radiator in order to fit my balancer puller, something I didn't want to have to do. So, not a pain in the ass in terms of time/effort, I guess for me it was just insult to injury, my brand new engine already needs new gaskets...