thunderstang

I got my engine started after about a year rebuild. Short block rebuilt by machine shop, everything else assembled by myself. To include a new melling oil pump. About once a week I would prime the oil pump with a primming tool and a cordless drill, turning thte engine over by hand and prime it again. (the oil pump would turn easy for the first few turns then it would put a load on the drill and start pumping oil up to the rockers and mechanical guage. about 40psi)

Started the engine for the first time and had good pressure, 50-60psi.
I ran the engine for about 4 minutes and shut it down. Started it a few more times that night and had pressure.

Yesterday I went to start it and I noticed my pressure was really low, it would come up to about 5 psi if I reved it a little. I shut it doen and started troubleshooting.

What I checked.
-plastic tube to guage good, compression fittings not overtightened,
-pulled the distrubutor and put my primming tool back in. Tried to prime with the drill again. Now the pump turns easy at first and stays that easy. No load put on the drill. when I stop the drill and listen it sounds like I can hear oil draining back into the pan.

I want to pull a valve cover to see if I'm even getting oil up to the rocker arms.

What do you guys think, I will be pissed if I have to pull this motor and replace a oil pump that has 10 mins on it.

Scraptor

Try spinning the priming tool the opposite way for a minute.
Maybe some debris is stuck in the pressure relief valve, and that MIGHT, dislodge it.
Check for air in the gauge line, it could be a bubble acting like a spring giving a false reading.
We used to prime them by hand with a speed handle and socket on the pump driveshaft, doesn't seem like they turned real hard.

Otherwise dig deeper, I feel for ya.
I spent all day chasing a no spark, no start, because the oil pump was broken, and on my dodge, the oil pump drives the distributor, so no spark, because the distributor won t turn.

thunderstang

It's not air in the line. I pulled it off from the gauge and ran it into a bottle, primmed with drill, I got a little oil to come through but no real pressure. I tried spinning it back wards and got nothing.

I know with the pump working if I spin it backwards I can hear the pickup blowing bubbles in the oil. I don't hear any bubbles anymore. DAMN

Lesbest

Sounds like the pressure relief valve in the oil pump is stuck, open. Any small piece of debris could make that happen.

Should still have resistance when you use the drill as it builds pressure, if not it's time to drop the oil pan.

Les

papa tiger

It has def blown out.

Never_Evil

What is the clearance of the pick up to the oil pan? Maybe the bolt that secures the tube to the block has backed out allowing your pick up to drop down and pull out of the oil pump. Another possibility would be a hole formed in the pick up tube.

13Harleyfan

Bite the bullet and pull the pan, check for debris and inspect as much of where the bearings and caps sit. I would ask the machine shop if they could have some inspect the engine before you throw a pump on it and find something else is the problem.