i have a 72 340 that was freshly built and running for a short time before i got it, but mice got in it and filled the intake with corn, so i tore it back down, cleaned everything and put it back together. i got it running again and im not getting oil pressure at idle and only about 20psi when its revved up a little. i prelubed it with a drill once before and i got about 20 psi. the engine is now in my 94 dakota and the oil pan is very hard to remove. im looking for any advise for things to check without pulling the pan. any help would be great

Much as you dont want to hear it, you have to pull the pan. I went through the same thing with a 360 I bought. With the pan off I found a half a dozen dead mice in the bottom and a few in the pick up tube screen. Previous owner had drained the oil and left it empty. The mice made a cemetery there. Is your Dakota a engine swap, if so it should not be to hard to just pull the whole engine. My 90 engine swap was pretty easy and I plan on doing it again once I get an oil pan for my 408.

i took the engine all the way down pistons,heads,oil pan and all. it should be completely clean as far as that goes. its a new pickup and its been sealed up tight since i put it back together so mice couldnt get in again. it just wouldnt make any pressure so i changed guages and it didnt change.theres no leaks externally and the engine sounds fine. im at a loss

is the plug installed behind the cam plate?

it should be i dont know why i would have had to remove it

I bought a motor that the plug had been left out of. I found it when I primed the motor, Oil poured on to the distbutor gear location when I turned the oil pump.

when u said running for a short time...how short was that and did it have oil pressure then?...

it was in a car for about a year and i would assume it had oil pressure. the guy who had it built it right and had alot of cash in it i dont see why he would run it without oil pressure

Do you have a remote oil filter?

It sounds like a vehicle with crossed remote oil filter lines to me..??

If no remote filter and the valley end plugs are in it's a tough guess..

theres no remote filter i just have a 90 degree adapter

Did you check the oil pickup screen?
Sorry, but I ain't up to speed on your situation yet!

Have you tried an independant mechanical gauge into the back of the block?
Have you tried priming it with a priming tool with an independant mechanical gauge?

yes a tough one. you might pull the dist/intermediate shaft/oil filter & spin the pump(CW) w a priming shaft & see how much flow you have at the 90 degree adapter as you spin the drill at varying speeds which would let you see whats up at the beginning of the pressure side. If good I'd pull the intake & prime it again & see what you see.

yeah the pickup is brand new. it never ran with the mouse nest in it, but i decided to tare it all the way down anyway to make sure i wouldnt have problems. all i did was pull the intake, heads and pistons, cleaned them and put it back together

maybe the pressure relief valve is stuck open?,it happened to me on a ford and also on a chevy

all i had was a mechanical guage, so i tried another one and i still had no pressure. i took the whole setup and hooked it up to my old worn out 318 van and i was getting almost 40 psi at idle, but it was cold. either way my mechanical guages are obviously fine.

is the pressure relief right in the pump?

What did the bearings look like when you pulled the pistons? Did you pull any mains to see what they looked like?

i looked at all the bearings since it was apart and they all looked good. overall every part i took out looked almost new, but i didnt actually pull the cam or crank

once i had a reman chevy that seemed to have pressure when you used a drill to prime the pump,but it wouldnt show any on the gauge,turns out there is a small soft plug that fits in the oil galley that directs oil thru the filter,the plug was out of place as in pushed up to far ,and the oil would go thru the filter but wouldnt get to the bearings or the gauge,does dodge have a similar setup??,seems like they might