• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

No oil pressure after oil change on 440???

I would try another gauge. I did have a oil filter clog once on a old 360 in a dodge adventura but it was filled with sludge. Also had a oil pump fail once. Its just troubleshooting at this point.
if you have two people,try rotating the crank while you are running the drill.that will line up oil feed holes easyer and allow more flow.easy to do just to check.
Primed mine yesterday manually with a dewalt cordless drill hooked up to it on high speed, got er up to 70 psi.

How old is the oil pump?
Has been spinning the drill like crazy! Got a pressure reading of only 10 on the gauge after spinning the drill for maby 1 minute+! How much should it read...........50? What the h... is going on?

I would expect 30-45 psi. Turn the crank a quarter turn and try again.
What rpm is your drill maxing out? Some are low, like 350 I think. Remember your pump runs 1:1 revolutions with the distributor. Idle rpm is around 700?
If you have white plastic tubing for your oil pressure gauge do you see a solid line of oil to the gauge or do you see air in it?
Maybe get another gauge to verify and tie it in where you can see it while priming.
Have you checked the filter lately to see if it filled? You might try a different filter I have had them fail before. And they do not have to be full of sluge.
If you have white plastic tubing for your oil pressure gauge do you see a solid line of oil to the gauge or do you see air in it?

Like Daves69 says...what kind of tube do you have for your pressure gauge?

Bottom line is this. If there's any air inside that tube, gauge doesn't read right! So, on the block, tube is hooked to the oil pressure outlet at the top rear of the block, right? There's actually two, almost side by side, but different angles.

Is there oil, or air, in the gauge tube???

Just priming by hand, you could pull the tube fitting at the block. Prime to see if you get any oil out. Always possible, if air is trapped in that oil port, going to the tube/gauge, the air has no place to go. If you get oil at the gauge port, hook the tube back up, and like I mentioned before, crack the line at the gauge, and prime until the gauge's tube is full of oil.

Keep in mind, both of those oil gauge ports are fed via the main rocker arm oil galleys. Because of the design, the oil ports that feed the two rocker arm galleys, work off the cam oil ports. Depending on who built the motor, and parts used, it takes rotating the motor by hand (half rotation, or so) to feed oil to BOTH sides of those main oil galleys, and to both oil gauge ports.

Then see what you have. If you don't get at least 25-30 lbs pressure after that, I would NOT run that motor, until you find out why no, or little pressure.
Last edited:
why not go buy another cheap gauge and hook it up to your line and see what the New gauge reads??
that would eliminate the gauge,and then proceed?

btw,if you have the cheap plastic line that should be changed right away to a brass line or something Solid.
if that plastic pos ever breaks it Will shower the exhaust and trans with oil,yanno,hot flammable oil....just a thought,seen it happen.
I have removed the oil pressure outlet from the back of the engine, and indeed, I get a small amount of oil out thru there, when priming the pump. Hooked it back up - connected my copper line to the outlet, and left it in a bottle inside the car.......not connected to the gauge.......primed again - still without any oil coming out - one drop maybe! Connected the line to the gauge, and primed again with a person monitoring the gauge movement.................pressure only 10 PSI!!!
Last time it ran - before I drained the oil and coolant, oil pressure was 60-70 PSI...................what has happened since then - the car has been standing still? I will pull the pump next to see, if the PRV is stuck or the spring is broken.............but that would be some coincidence if that is the case! But I need to be sure, that I can get a hold of a new pump, before I take the old one off, because parts for Mopars are scarce here in Denmark.............I waited allmost 4 months on my radiator and shroud to arrive from the US ( mostly due to incompetent people sending me the wrong parts twice!!!). That is also why, it has been sitting for so long.
Bearings do not wear out by sitting still in the garage...................................so it must be at the pump - it has to be!
Did you try rotating the crank at all while priming?

Pull that relief out, make sure it's free.

Here's the flow diagram. Second pic is the cam journal oil ports for the rockers.


  • BigBlocOiling.gif
    41.9 KB · Views: 352
  • BigBlocRockerOiling.gif
    4.1 KB · Views: 320
I did not rotate the crank - that way I would loose my timing marks..........! I did, however put the distributor back in - turn the crank - make new timing marks - remove the distributor, and then prime it again.
I tried removing the relief valve last night, but the wrench I have was too large for me to turn - too little room. I will try to get hold of a smaller one, and remove the valve for inspection. Will keep you posted.
Dk440...You say only a small amount of oil through the line pressure oil ports (ones at rear of block)?

If your pre-oiling enough to fill all the oil ports, should have gotten pretty good flow to there. Almost sounds like some kind of blockage. You might try running a rod though those two ports, to see if they are clear.

First pre-oiling you did, sounds like you are getting flow from your pump, and from what you say, was getting good pressure.

440...my first one...all before 383s. Don't know what year your motor is, might not matter, but overhauling mine I ran across stuff never found before. Dang block would rust at the drop of a hat! Including in oil ports, and on mine, the main feed galley from pickup tube to oil pump was almost rusted SOLID.
All your looking at are holes, that need to be clear. Hope it winds up something simple...just takes checking things out.

Oil flow to those rear pressure ports, sounding way too low.
I don't understand why you didn't rotate the engine while priming. That's how the oil feeds line up to give you oiling to the upper engine. Just priming without rotation tells nothing.
I don't understand why you didn't rotate the engine while priming. That's how the oil feeds line up to give you oiling to the upper engine. Just priming without rotation tells nothing.

Maybe I'm wrong but I believe, if you look at the diagram, oil runs up over the #1 main into the right main block gallery. At the rear, I believe, the gauge port is shown but not labeled. That port, if open, should flow freely unless there is another path of least resistance, or it's restricted, or pump fail.

- - - Updated - - -

I did not rotate the crank - that way I would loose my timing marks..........!...............

There's a second oil gallery port back there you can try if the current one is restricted.

For future reference you can rotate the crank two full revolutions and be at the same timing position.
Also, as a matter of my own preference, when changing oil and filter, I've ALWAYS pre-filled the filter at least half on big blocks for the last 40 years. I look at it as it can help prime the pump and it's that much less "fill time" for new oil to get in the bearings galleries. To me wiping up a bit of spilled oil is much easier than fixing bearings that ran dry.
Been away for a few days, but finally took a look at it again yesterday with a buddy of mine. This time, I fired the engine up after priming it. Still no oil pressure, and now you could hear a definite whining sound from inside the engine, like something is extremely tight/rubbing! :eek:(
I assume, like some has allready mentioned, either a spun bearing og a warped piston ring after overheating issues last fall............! I will remove the pan shortly, and have a look at the bottom end.
Thank you all for chiming in!
had the same happen to me but under acceleration a tooth off the timing chain got int the valve i just removed the relief valve and removed the piece of metal re -installed the valve and the pressure was back to normal
You can remove the relief valve and inspect without removing the whole pump...
i have seen this several times in my 30 years as a mechanic and mopar lover,remove the oil filter then have a buddy spin the oil pump with a drill while you squirt oil in the pressure side of the pump[not thr threaded fitting the filter screws up on but the other hole]it will prime the pump and start pumping oil
I've had the same problem with my 400 Highly recommend using NAPA Gold filters for your big block. filter has a check valve which prevents the oil from draining back into the oil pan thus a dry start. Priming your filter and system as summarized above after you install the new filter and new and lighter oil should resolve your concerns.
Is old oil filter colapsed internally?
Also mechanical guage is line semi clear plastic? Can you see oil behind guage or at back of motor??? Just a thought!!