No oil pressure

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Harold Schutz

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Getting ready to fire up a complete engine rebuild (69 Plymouth 318). Prelube is not getting any oil pressure and only a very small amount of oil to the test gauge. Nothing to the valve train. I took the filter off and have full flow to the filter so that tells me the pickup and pump is working fine. Not sure how the flow is routed through the engine and where to check for oil flow. Any suggestions?
 
So the engine is not running yet and you are priming the engine? At this point you are seeing low pressure during priming and no oil to top end? Clarify.
 
Install a manual oil pressure gauge in the oil pressure port next to the distributor and see if you have oil pressure there. If so, then as Steve mentioned, you need to torn the engine a little at the time and prime each time for a few minutes. It can take some time to get oil to the top.
 
RustyRatRod said:
Install a manual oil pressure gauge in the oil pressure port next to the distributor and see if you have oil pressure there. If so, then as Steve mentioned, you need to torn the engine a little at the time and prime each time for a few minutes. It can take some time to get oil to the top.
Click to expand...
I have manual gauge installed and zero pressure, so not sure how rotating engine is going to help anything but at this point I am willing to try almost anything.
 
Harold Schutz said:
I have manual gauge installed and zero pressure, so not sure how rotating engine is going to help anything but at this point I am willing to try almost anything.
Click to expand...

If there is oil getting to the filter but not to the oil pressure port then you have an internal leak somewhere.

There is no way to get oil to the rockers if you don’t turn the crank. Unless you happen to have the crank parked where the oil hole in the block is lined up with the oil holes in the cam.

I think there is a sticky here or somewhere that gives you the degrees before and after TDC to get the oil holes lined up.
 
Newbomb Turk said:
If there is oil getting to the filter but not to the oil pressure port then you have an internal leak somewhere.

There is no way to get oil to the rockers if you don’t turn the crank. Unless you happen to have the crank parked where the oil hole in the block is lined up with the oil holes in the cam.

I think there is a sticky here or somewhere that gives you the degrees before and after TDC to get the oil holes lined up.
Click to expand...
I remember posting positions for a motor I had on the dyno in a thread somewhere here. Don't quote me but I don't think all the motor positions that were posted were exactly the same. Either way I would find out why there is no pressure first. Maybe an oil plug got left out of the block?
 
92b said:
I remember posting positions for a motor I had on the dyno in a thread somewhere here. Don't quote me but I don't think all the motor positions that were posted were exactly the same. Either way I would find out why there is no pressure first. Maybe an oil plug got left out of the block?
Click to expand...

After your post, I posted 3? sm blk cams with oil holes in different locations, which woulda thrown those marks off.

I suggested a sticky including the fact you gotta turn the crank 2 revolutions to get the cam to turn once.
So swinging the crank back and forth thru 360* is only gonna get oil to one side .
No oil to the other side until second crank rotation .

But
 
There was a member who JUST experienced this same thing very recently. He ended up removing the pan, priming the pump and that fixed his issue.
 

RustyRatRod said:
There was a member who JUST experienced this same thing very recently. He ended up removing the pan, priming the pump and that fixed his issue.
Click to expand...
I came close to that. It took quite a while to get pressure on my 340. Almost gave up then bingo!
 
Get a 2nd person to help, makes it easier. Rotate engine slowly while 2nd person runs drill. It took quite a while for our 340 to show flow. And like mentioned above there are more than 1 or 2 different orientations for oil flow.
Also as a precaution, let's see pics of rocker shaft orientation
 
woah woah woah now fellas. we can't be talking about the alignment of oil holes in the crank and cam! that topic isn't in season!

hell, it's not even the autumnal equinox yet!
 
OK the pump evidently works, did you pre-fill the filter? Maybe you did not give the system time to fill the filter and develop pressure?

WHAT DID YOU DO TO THE ENGINE? Did you have it torn down to bare block? hot tanked? Did you or someone open up the oil passages to clean them? If so, there are a number of plugs, if someone else was involved, that can screw ya up

1...There are plugs in the front oil passages, also normally covered by the cam retainer. That might be an issue

2...At the rear of the engine, inside the bell, are three plugs. ONE of them is a trick. You remove the plug, it provides for ANOTHER plug inside the valley, near the dist. Pull the dist and look down the hole, you can see that plug if it's installed. Plugs the rear of the driver side lifter passage but INSIDE the block.

3..There's a trick plug (I forget is there 2?) in the oil pump / filter passages. One is in the vertical passage with the pump output at the bottom and the gauge port at the top. There is a way to stick a rod down the gauge port, measure it, and determine if that plug is properly seated

4...Some pans interfere with the pump and can force it over enough to break the pump. Keep that in mind

Part of it this thread
www.forabodiesonly.com

340 oil galley plugs

I'm looking for verification on an oil plug problem. My brand new 340 build destroyed the main bearings in 6 hours running. Found metal on the magnetic pan plug. Changed the oil 4 times thinking the machine shop didn't clean the block and it was flushing but the metal kept coming. I know I...
www.forabodiesonly.com www.forabodiesonly.com

The drive in plug in the vertical passage
www.forbbodiesonly.com

360 Oil Galley Plugs???

I'm rebuilding a mid 70's 360 and I need to make sure I have all my plugs in place. I know that I have all the ones in place that I took out including the one in front of the distributor drive, accessed and recessed from the rear. I was online and found this article and I can't figure out...
www.forbbodiesonly.com www.forbbodiesonly.com

Another. Look particularly at the photo in post no. 7

www.forabodiesonly.com

Inner sactum oil galley plug

It looks like we hot-tanked my 340 block without having removed a "hidden" oil galley plug. I am getting ready to final clean block oil supply lines with nylon brushes. Is it necessary to remove this other plug? If so, does an allen wrench 5/16" fit perfectly? And is this plug usually a bear to...
www.forabodiesonly.com www.forabodiesonly.com
 
Last edited:
You need to go to the FSM to see the oil galleys in the block. The top end oil galleys are run through the cam on its way to the top end. Those oil galleys at the cam are only aligned briefly during the engine rotation. So the cam and its position is needed for oil to flow to the top end. And this is NOT at TDC. No oil will flow to the top end at TDC. You must rotate the engine.
 
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