New engine with no oil pressure.

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Dust4U

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Building a 408 cid for a 1974 Duster. I have built a few small block 340’s in the past and only had one issue with oil pressure. (Machine shop forgot to put the internal plug in by the distributor)
I went to start the new 408 and the oil pressure gauge never even budged. I bought an oil pressure test gauge and the same result.
Has anyone had the same issue of having zero oil pressure or have any suggestions on what to look for before I drop the pan and replace the oil pump or pull the engine?

IMG_5813.jpeg
 
I assume since you brought up the dreaded oil galley plug, you double checked that it is installed? But that said, yes. I have seen a new engine not have oil pressure. As stupid as it sounds, the builder stuffed the oil pump FULL of lubriplate white engine assembly grease. The rotors could not pull anything in to push it out, so we had to disassemble to investigate and that's what we found. Not that I would ever recommend doing that, but I actually couldn't believe that would stop a pump from pumping, but it dang sure did. We cleaned it all up and it buried a 100 PSI gauge on startup. It was a Mopar small block. A 340.
 
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Didn't you prime it? Are you aware of the plug in the rear lifter gallery, that inserts THROUGH a plug hole at the rear of the engine?

Remove filter. Get or make a priming shaft. REMOVE THE FILTER. RE--check oil level!!! Put a pan on the ground and use a drill, CLOCKWISE, AKA "normal" drilling rotation. That thing should pump oil out the filter hole in about 1 second.

Do you best to fill the filter. Fill it up, tilt it and rotate, to allow air to work out, and to allow oil to absorb into the filter. Fill it some more. Prime again, with filter installed. Drill should "lug" heavily

Are you aware of rotation of the crank to get oil to lifters? I would prime until you do.

If you have a second person, see if the gauge shows pressure when cranking the drill. You can use ANY gauge for this, including a compression tester.
 
in the past i swapped a good rover v8 (rebranded buick 215 here in the uk) for a 'dead' one in a mk3 zodiac i had. it wouldn't make oil pressure and after making a call or 2 i found you have to pack the oil pump gears with vaseline if the pump's allowed to drain as in when the oil pan's swapped. it dissolves in the oil in use as it's basically petroleum jelly so that's ok. anyway we had no vaseline at work out in the sticks so had to come up with a plan b. my solution was to fill the motor's oil level to above the pump on the basis that gravity would prime it when it turned. it worked and made pressure with a couple of seconds so i just had to drain the oil pan. the foamy oil (4.5 gallons, lol) we left to settle overnight and just added more new oil to finish the job and allow me to get home. :thumbsup:
neil.
 
There can be an issue with rear main bearing cap aftermarket replacement studs/NUTS have interference with the oil pump, not allowing the pump to "seat" correctly on the brg cap, allowing the oil to escape thru the opening/gap.
Are you cranking the engine, or using a primer shaft clockwise.
The oil filter has to fill
 
The second rebuild on my 340, my dad installed the gear drive and it wouldn't go down, so he took a hammer, flipped it over to the handle end and just let the weight of the head of the hammer tap it down from about 3" from the drive gear. It went in, we buttoned it up and no oil pressure. Pulled the pan and that small of a pop broke the pump, it was still hanging there but not being driven.

Any auxiliary oil filter relocation or non stock things done tot he oiling system?
 

Recently freshened up a 340. Primed it on the stand to check everything was ok, for leaks etc. showed over 60psi with the drill priming check
Put it in the car and when we first started it all was well with 75psi. On the next day started the car and no oil pressure. Quickly shut it down
Checked the oil pump drive shaft. It was fine. Used the drill/priming rod and a mechanical gauge no pressure. Drained the oil to see if the pickup tube was still in place with a inspection camera. It was
Pulled the engine back out pulled the pan and pump found that the pressure relief piston was stuck in the open position was a small burr on it and about every third time we pushed it over it would hang up. Crazy. Good thing it did it in the garage and was caught quickly not going down the road at 65mph
 
Dust4U said:
Building a 408 cid for a 1974 Duster. I have built a few small block 340’s in the past and only had one issue with oil pressure. (Machine shop forgot to put the internal plug in by the distributor)
I went to start the new 408 and the oil pressure gauge never even budged. I bought an oil pressure test gauge and the same result.
Has anyone had the same issue of having zero oil pressure or have any suggestions on what to look for before I drop the pan and replace the oil pump or pull the engine?

View attachment 1716431916
Click to expand...
Kendallville?
 
4mulas said:
Possible easy to to check. Have you done any checking on anything that could be related?
Click to expand...
I pulled the pump drive and it was good.
I’m going to pull valve covers and check to see if rockers are getting oiled. I put an oil filter relocation kit on it. I’m going to pull the “out” hose off by the filter and make sure everything is flow through that fine. This is the first time using a relocation kit and I’ll say I’m more of a 90 degree adapter fan after installing the kit. Just to many places for failure IMO.
I had the oil pan off for another reason and I’m confident that the oil pump base is flush and secure with the main cap.
Updates to follow…
 
You remember to install the pickup sump? (I've seen it missing a couple of times on cars I bought with the same problem as yours! Owners finally gave up and sold the car.) Proper amount of oil in the pan?
 
if the pipes are plumbed the wrong way on the remote filter housing and the filter has a non return valve in it then it makes sense oil won't flow through it. worth swapping the pipes over and trying to prime it again.
it could be that simple..... if you're lucky.
neil.
 
Hopefully it didn't snap an intermediate shaft.

Whenever you install an oil pump, always pour a little oil in it and spin the rotor, that's primed enough for it to draw oil immediately through the pickup upon cranking it.
 
mygasser said:
if the pipes are plumbed the wrong way on the remote filter housing and the filter has a non return valve in it then it makes sense oil won't flow through it. worth swapping the pipes over and trying to prime it again.
it could be that simple..... if you're lucky.
neil.
Click to expand...
 
Today must be my lucky day!! That took care of it. 60 lbs of pressure while priming.
Thank you for the tip and everyone else that was posting. I’m very appreciative.
 
Dust4U said:
Today must be my lucky day!! That took care of it. 60 lbs of pressure while priming.
Thank you for the tip and everyone else that was posting. I’m very appreciative.
Click to expand...
Don't feel bad. It's been done a lot in the past.
 
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