No oil pressure on fresh rebuild

[HopRod]

Just tried starting new rebuild and could not develop any oil pressure. I previously forced oil in the rear tap a couple weeks ago to prime the pump, but has been two weeks ago. The motor started, saw the oil pressure gauge flutter a little bit and then settled on 0. I thought it should have picked up the oil from the pan. Using electric fuel pump with push rod hole plugged. Front galley plug is installed.
Any thoughts?

[flatjack9]

Remove the spark plugs and crank the engine until you see some pressure.

[petehoovie]

Did you fail to pack the oil pump with Vaseline or light grease?

"Don't ever just install a new oil pump right out of the box. There are two easy methods of insuring the oil pump will create the seal needed to pull oil in on initial start up. The first method is to pack the oil pump full of Vaseline. Vaseline will create the seal needed for vacuum to draw in oil. The Vaseline will then be quickly dissolved into the oil. The second method is to use engine assembly lube and lube all the moving parts. The goal here is to sufficiently coat all moving parts so when the pump spins for the first time vacuum is created to draw the oil into the pump and then push it through the system."....

[Lawrie]

Another way if you had not done the above is, get a small hand operated vacuum pump from any parts store, adapt it to the port where the oil pressure sender is and pump up a vacuum, then crank the engine while pumping the vacuum, it should be able to prime itself if all is well on the pump side.
Lawrie

[69a]

You can also over fill the oil level to above the oil pump gears. Let it sit for a few hours and crank it over till you get pressure. You can also remove the oil pressure sensor and crank it until oil comes out of the gallery. Drain the excess oil out and refit the sensor before you fire it up.

[Don]

Sponsored Links (Register now to hide all advertisements)

Is the spring in the pressure relief under the intake manifold??

[robib]

What brand camshaft did you use? Just did a rebuild and had no oil pressure after awhile. Turned out it was the gear that is pressed on the rear of the cam for the oil pump. Did not have the proper interference fit and was slipping. It was an Isky cam. Can be checked at the back of the engine, if the engine is not installed.

[Frank Miller]

Did you remember to install the galley plug?

[marko39]

Originally Posted by robib

What brand camshaft did you use? Just did a rebuild and had no oil pressure after awhile. Turned out it was the gear that is pressed on the rear of the cam for the oil pump. Did not have the proper interference fit and was slipping. It was an Isky cam. Can be checked at the back of the engine, if the engine is not installed.

There is also a plug in this area which must be installed.

[Automotive Stud]

Hope it's not this but I had it happen to me. Idler gear behind the flywheel was installed backwards so it wasn't meshing with the oil pump. Pulled the oil pump and was able to reach the idler with a long screwdriver to see that it was freewheeling, had to pull the motor to correct it.

[Ol' Ron]

I always pored some oile down the vertical oil pressure port on the back of the block. This usually worked if it wasn't some other problem. Back in the 90s when I started building engines for other people I used mellings oil pumps. Most of these were junk and had to replace several. since then I've only used stock Ford pumps. They never wear out because they are well oiled
Graps.

[Jack E/NJ]

>>>saw the oil pressure gauge flutter a little bit and then settled on 0. >>>


What pressure gauge?

[jimvette59]

Do you have a electric gauge or mechanical gauge ?

[Flathead Fever]

Originally Posted by Ol' Ron

I always pored some oile down the vertical oil pressure port on the back of the block. This usually worked if it wasn't some other problem. Back in the 90s when I started building engines for other people I used mellings oil pumps. Most of these were junk and had to replace several. since then I've only used stock Ford pumps. They never wear out because they are well oiled
Graps.

I have also done what OL' Ron does too. I also had a new Mustang 289 engine that would not prime until I removed the oil filter and pumped oil in through the threaded adapter. Now if I could only figure out why my 1/2 horsepower pond pump won't prime??? I turned it off to clean the strainer and it never pumped again. New O-ring, no air leaks. I even made an adaptor for a hose to force water into the inlet. I think it's finally worm out after 15 years. It just bothers me that it was pumping 3000 gallons an hour 24 hours a day until "I" touched it. The upside is my electric bill has gone way down.

[Tim Ayers]

I just fired my motor up yesterday and did what Ron suggested. Filled that port up with approx. 3/4's of a quart of oil. Used 20/50 VR-1 racing oil.

Only had a 50 lb gauge hooked up and it pegged it instantly.

Something else to try is do all that and spin the motor over without the plugs. This will allow it to spin faster. Give it a few rotations and see if the pressure gauge moves.

Put plugs back in and fire it up to see if that gives you oil pressure.

[deuce_roadster]

I heard there were water shortages down there! (I know it is a closed system) Any chance there is a safety valve in it that blocks the input or shuts it off when the pump is lying in its side? Probably reached its warranty limit of gallons after 15 years.

[Desoto291Hemi]

Sounds like the idler drive gear on rear is installed wrong direction .
That’s a real problem to fix if that’s the case .
Or,,,it could be the drive gear on the rear of camshaft ?

Tommy

[Lawrie]

Is the idler gear made so it cannot go on the wrong way?
Lawrie

[Ronnieroadster]

Originally Posted by Lawrie

Is the idler gear made so it cannot go on the wrong way?
Lawrie

The idler gear can be installed backwards if its an 8BA and for a short period the gear teeth will mesh so there would be oil pressure but not for long. Early blocks the idler gear cover will not allow the gear to be installed backwards.
Ronnieroadster.

[Lawrie]

Thanks for that, I mostly work on the early engines, except our dragster has an 8ba
Lawrie