Normal idle is between 30 and about 40 depending on the engine, oil pump and oil.

 

Well i have 10-15 PSI when warm at idle and im hoping your talking about when its cold which i have 55-60 PSI cold idle and while running down the road warm its also 55-60 PSI

 

Yeah, cold psi, my bad. Mine is about 40 cold.

10-15 warm is still a tad low.

 

Thats what i was worried about. I don't understand why its so low, but my truck just has a sensor not a gauge for oil pressure either off or on so i really dont have a clue what it was running before?

 

Well that leaves a mechanical problem with the engine rebuild itself, unless you're using the wrong model number oil pump?

What exactly was done to "rebuild" the engine?

Did you do the rebuild yourself or did someone do it for you?

If the bearings on the crank were not wearing correctly then I am inclined to think that there is a problem with the crank itself.

What was the reason you rebuilt the engine in the first place?

If you had oil starvation or failure and you spun a bearing, then you might have bent the crank (very hard to do but def. possible).

Before rebuilding the engine you should have checked the crank at each bearing with a dial indicator to make sure it's good.

If the crank is okay then you might still have some "sludge" inside the oil system, so you might want to run some seafoam through the oil and see if you can get it all to pass through the system.

 

I did do the rebuild myself, new crank from oreillys, new bearings from oreillys, the bearings where wearing top and bottom but about a quarter inch on both sides where they meet was not worn, like the bearings where to tall. I did not check the crank they sent me a kit with bearings and crank all together. The block is bored over with the correct size pistons from a machine shop. I origanally spun a #7 rod bearing so i completly rebuilt it. The block was dunked in a bath so i think its not sludge. I definently know now the bad gas got into the oil and fudged up the bearing for sure on the crank.i two think the crank is not right somehow, and for some reason i wonder if the rods and bearings are the right size. I did'nt check them trusting the parts store.

 

everything is new except the cam and block itself, i tryed replacing the oil pump and no change, the bearings worked fine untill 20,000 miles after rebuild directly after diesel gas mixture got into the oil.

 

Okay so let's get this timeline straight.

1) You spun #7 bearing
2) You rebuilt motor with new internals & bored over
3) 20,000 miles after rebuild a diesel gas mix got into the engine.
4) You are having Oil pressure issues

Well I can tell you right now that diesel usually has an approximate octane rating of 50, and gasoline starts at 87 and works it's way up from there.

Now if you lowered the octane enough, you could have knocked really bad, and bent a rod, or busted up your brand new internals somewhere....

I don't know what happened or how it happened, but from the sounds of it there is something mechanically wrong with your engine and as a result it's affecting the oil pressure.

If you have the tools to do it, I would do a compression test on each cylinder and see if maybe something went wrong in there.

Regardless I would personally be pulling that engine again to pull the heads off and pop each piston out to look for any problems.

I'm having some trouble understanding what you mean by "the bearings where wearing top and bottom but about a quarter inch on both sides where they meet was not worn" So if you have a picture of what you mean that might help.

Honestly from the sounds of it something is definitely wrong mechanically if you are only reading 10-15 PSI at idle with a separate oil pressure gauge then there is definitely something wrong, but just to make sure... where and how exactly did you tap into the oil system with your pressure gauge?

And what type/brand/etc gauge are you using to read the oil pressure?

 

The thing i dont understand is there was and still is 0 noise coming from anywhere i was just having my gauge peg out at zero and shoot all the way to over pressure and back and fourth.I will have to check compression this weekend but i don't think its that the truck runs to good and is'nt missing or having acc problems or anything noticable. I dont have a picture right now but where the two bearings meet on the sides, where the oil bearing and the regular bearing meet or butts up together where small clean un touched areas on the bearing like it the bearings where oval instead of round or something. I also have to add now that i replaced the bearings my oil pressure is 10-15 at idle and 55-60 running when before it was 0 at idle and 15-25 running. And the gauge i have is just a crappy 19.99 gauge from oreillys thats about 5 or 6 years old that leaks a bit.

 

I think it's time for a new gauge... your oil pressure might be okay, but the gauge might be out of wack....

Try a new gauge before you tear into that motor... remember to get yourself some YELLOW Teflon tape to put around the threads of the gauge and it shouldn't leak...

might be worth your time to do a compression and leak down tests to see if maybe a seal somewhere is gone or going....

Also what oil weight are you using?

This seems like a real interesting mystery problem.... it's hard to tell if there actually anything wrong b/c you aren't exactly using OEM parts, so it might be a different Oil pump than OEM...