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383 Low oil pressure,

__Larsson____

__Larsson____

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The carb flooded the motor with gas and that made it not lubricate properly

20200403_091443.jpg
 
Last edited:
What numbers do you get cold/warm at idle and say 2000 rpm?
Hate to tell you but you likely have a worn motor.
The oil pumps rarely ever fail in these cars.
A thicker oil like a 20/50 might bring it up some.
 
Was it something sudden or has the pressure been steadily declining over a number of years? What pressures are you getting currently at hot idle and 2000rpm? What oil are you using? Type of pump?
 
Don Frelier said:
What numbers do you get cold/warm at idle and say 2000 rpm?
Hate to tell you but you likely have a worn motor.
The oil pumps rarely ever fail in these cars.
A thicker oil like a 20/50 might bring it up some.
Click to expand...

20psi cold, then goes down to 0 after a while, engine rebuilt exept for the cam and pump. The motor had great oilpressure before i took it all apart an ran beautiful. Bought 15W40 today i'm going to try and se what it does along with the new pump. I hope i dont need to take it out again......
 
turbine68rt said:
Was it something sudden or has the pressure been steadily declining over a number of years? What pressures are you getting currently at hot idle and 2000rpm? What oil are you using? Type of pump?
Click to expand...

I have been restoring the car for about 4 years and before i took it apart it all ran beautiful. My uncle rebuilt the motor exept for the cam bearings and the pump,
 
Not good.
Maybe the main bearings have too much clearance.
Hopefully an engine builder here can give you suggestions.
I can assemble one but certainly no master machinist/engine builder.
 
I would try changing the pump, it’s the easiest thing to do. It being a fresh rebuild, I’d bet it has the wrong main bearings, maybe wrong rod bearings? There is a plug in the front of the engine that’s easy to forget to put in, but without that plug I don’t think you have any pressure. Good luck.
 
before you replace anything remove the pressure bypass and check that is not stuck and see if the spring is in good shape. go to my mopar . com and down load the manual for your car and read the engine section then see where the trouble shooter leaded's you.
 
Worn cam bearings will do this. Also, not sure what you have or have not done to "rebuild" the motor, but as stated, putting std bearings on a crank ground to 10/20/30 will do this.
 
vance.dykes said:
before you replace anything remove the pressure bypass and check that is not stuck and see if the spring is in good shape. go to my mopar . com and down load the manual for your car and read the engine section then see where the trouble shooter leaded's you.
Click to expand...

Pressure bypass? On the pump?
 
Square headed bolt head (5/8"(?))on firewall side of pump.
 
"Ran great before it got taken apart" is the key.....something got missed. Easy stuff first--as these guys have said, check the pump and it's driveshaft. Then drop the pan and make sure nothing funny's going on, like a paper towel or big gob of silicone jamming the pickup (it happens!). At that point, since it's likely gotta come out anyway, I would first pull the intake and valve covers and prime it with a drill motor while slowly rotating the engine, and watch and listen for any obvious leakage. You may get a clue where the issue is before taking it apart..
 
what if ??? are you using a stock fuel pump ?? if not and the fuel pump rod is missing could that be a loss of pressure ? and what about the front galley plugs ???
 
vance.dykes said:
what if ??? are you using a stock fuel pump ?? if not and the fuel pump rod is missing could that be a loss of pressure ? and what about the front galley plugs ???
Click to expand...
I would say no on the pump pushrod as it's not connected to a pressurized oil passage. A galley plug could definitely be a cause, but I would think he wouldn't even see that initial 20 psi? OP said it gets 20 'for awhile', but what does that mean? Could be 5 minutes, or 5 seconds..
 
vance.dykes said:
what if ??? are you using a stock fuel pump ?? if not and the fuel pump rod is missing could that be a loss of pressure ? and what about the front galley plugs ???
Click to expand...
If the fuel pump rod was missing without an electric fuel pump it will not run.
 
What weight of oil you presently useing? These were not designed for 5-20. 10-30 would be a minimum.
 
I have a leak in the rear crank seal could that have the effect? Its not that big. The oil had fuel in it thoe. That damn electric choke makes the carb to get flooded. Can you make an Holley electric choke to inactive? I will try to buy GULF oil 20W50 tomorrow and se what happens. Thats
 
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