No oil pressure on fresh rebuild
 

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?

Re: No oil pressure on fresh rebuild
 

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

Re: No oil pressure on fresh rebuild
 

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."....

Re: No oil pressure on fresh rebuild
 

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

Re: No oil pressure on fresh rebuild
 

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.

Re: No oil pressure on fresh rebuild
 

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

Re: No oil pressure on fresh rebuild
 

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.

Re: No oil pressure on fresh rebuild
 

Did you remember to install the galley plug?

Re: No oil pressure on fresh rebuild
 

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

Re: No oil pressure on fresh rebuild
 

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.

Re: No oil pressure on fresh rebuild
 

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.

Re: No oil pressure on fresh rebuild
 

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


What pressure gauge?

Re: No oil pressure on fresh rebuild
 

Do you have a electric gauge or mechanical gauge ?

Re: No oil pressure on fresh rebuild
 

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.

Re: No oil pressure on fresh rebuild
 

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.

Re: No oil pressure on fresh rebuild
 

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.

Re: No oil pressure on fresh rebuild
 

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

Re: No oil pressure on fresh rebuild
 

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

Re: No oil pressure on fresh rebuild
 

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.

Re: No oil pressure on fresh rebuild
 

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

Re: No oil pressure on fresh rebuild
 

I don't think that the vacuum pump idea will work. Post #4 because you will just suck air through the oil pipe in the lifter valley. Post #11 would work. You can put a clear plastic hose in a fitting for the pressure sensor and fill it with oil. Take the plugs out and manually turn the engine back and forwards a couple of turns and see if the oil level changes. That will tell you if the pump is turning.

Re: No oil pressure on fresh rebuild
 

"Did you fail to pack the oil pump with Vaseline or light grease?" Used assembly lube.

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. ------ It is a Tatum designed cam ground by Schneider. The drive gear seemed secure when 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.
05-02-2022 05:44 AM---------That is a pretty logical explanation. I hope my problem is just a priming issue, but this makes sense. I'd be pretty upset with myself for making that mistake, but would never happen again.

I have a mechanical Stewart Warner gage that has been verified as working. I am going to pull the plugs, put some oil down the rear oil sensor port again and spin it over with the starter to see if I get any pressure. If none, then out comes the motor and will check the idler gear. If not that, then off comes the oil pan to pull the pump. I will keep you posted. Thanks so much for all the ideas and help. You guys are the best!

Re: No oil pressure on fresh rebuild
 

I had the gear on the cam come loose also. Ended up finally having the gear drilled and a installed a lock pin.

Re: No oil pressure on fresh rebuild
 

Note: If you can't build oil pressure by cranking the engine over with the plugs out - then don't start it . . . as something is wrong. You don't want to ruin all your bearings due to no oil pressure. :eek:

Re: No oil pressure on fresh rebuild
 

Sage advice:

When I pulled the plugs and cranked over my motor (6V starter in a 12V system), the motor spun over incredibly fast and oil pressure was almost instant.

If you don't get pressure after approx. 5-10 sec, shut 'er down and pull her out. If you don't, I'm afraid you'll just be doing damage.

Re: No oil pressure on fresh rebuild
 

I know it's not exactly the same, but I'll post it anyway. I had a '51 Mercury that sat under the stairs in my shop for at least 20 years. I did all the usual stuff (oil in the cylinders, made sure it turned over by hand, ran a compression test) and it looked real good. I got it ready on my run stand and turned it over with the plugs out 3 or 4 times for 10 seconds each; no oil pressure. I was getting concerned, so I removed the line to the mechanical oil pressure gauge. 3 or 4 more 10 second bursts and oil started coming out of the disconnected port. I hooked up the gauge again and another few turns and the oil pressure gauge started to show pressure . I then installed the plugs and the engine started almost immediately and showed good pressure. That was 6 years ago and the engine still runs great and shows good oil pressure (25 psi hot idle and 55 psi going down the road).

I can only surmise that over the long storage period, all of the oil drained out of the system. Why did it take so long to build up? Perhaps there was an airlock or something. All I know was that I was very nervous because it took so long to build pressure.

Re: No oil pressure on fresh rebuild
 

So, I did prime it with a qt of oil, had the plugs removed and cranked it over with the starter and no oil pressure was built up. . I knew then the engine had to come back out of the car. So got to work on that to get access to the rear idler gear. Pulled the cover and what do you know, I had it on backwards! I was relieved to find the issue at this point and gladly accepted that I had made a mistake. There was some wear on the idler gear and the cam gear, but just barely. I cleaned it all up and then used an old electric fuel pump to circulate oil from the oil pan into the oil sending unit port. It worked ok and filled the oil galleys with oil. I also spun the oil pump gear with my finger and it built pressure and spilled out of the rear cam bearing all over the floor.
I drained the oil through a white cloth and viewed any debris after draining. just some small discoloration and white assembly lube. I then pulled the truck pan clean out cover and looked around and all looked OK. Feel pretty good that no harm was done. Will work on reassembly of everything and get this thing fired up.

Re: No oil pressure on fresh rebuild
 

Congrats on sticking to it and figuring out the problem. Very happy to hear that it seems like no damage was done.

Get her wrapped up and back in and please report back once its in, fired up and driving around

Re: No oil pressure on fresh rebuild
 

We got the engine back in the car and fired up without incident. Oil pressure was good and no abnormal noises. Got it up to operating temperature twice so far and retorqued the heads each time. One more heat cycle and should be good on the head torque. Then need to set the carbs and timing.
Thanks to all those who replied and helped me along the way.

Re: No oil pressure on fresh rebuild
 

I love a happy ending!

Re: No oil pressure on fresh rebuild
 

Is the front plug on a 59A motor just a pipe plug?

Re: No oil pressure on fresh rebuild
 

No it is a 1/8 npt plug but it has an extended snout on it.