No Oil Pressure In My 300

azblackhemi

Old Man with a Hat
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Went to start my 70 300 Vert project and have no oil pressure. I'm guessing the oil pump quit on it. Last time I started it a couple of months ago it was fine. Not what I wanted to find. :BangHead:
 
Have you tried...
Did you check...
In 1967 the....
Try Murray Park...
I remember when...
Had one just like that...
I don't know, but if...
Damn ethanol...
Damn Chinese...
Hillary...
 
Happened to my 440 Belvedere a couple months ago. Put a new filter on it with about half full of oil. Pulled dizzy & pump shaft. Primed pump & reinstalled dizzy. Purrs like a kitten. Seems to happen to big blocks that sit from my mulling around on the net.
 
Went to start my 70 300 Vert project and have no oil pressure. I'm guessing the oil pump quit on it. Last time I started it a couple of months ago it was fine. Not what I wanted to find. :BangHead:

Bummer....

The good part is you can upgrade to a high volume pump! I'm sure you've done this before but in case you haven't. Just loosen the motor mount jack the engine up about 3/8" and the pump comes right out. Maybe there is a better way? If so.....let me know.

Good luck Sir!
 
Have you tried...
Did you check...
In 1967 the....
Try Murray Park...
I remember when...
Had one just like that...
I don't know, but if...
Damn ethanol...
Damn Chinese...
Hillary...
^This^

Or if it's not that... The oil pump drive shaft will sometimes shear it's pin to the distributor gear... or possibility the pickup is plugged with crap. Never seen a big block oil pump fail though.
 
The hex fitting on the oil pump drive shaft will also sometimes break off, but that is a rare failure. As suggested above, remove the distributor and the drive shaft for the pump and try spinning up the pump to see if it will generate pressure, replace the oil filter first. If you still have a plastic faced timing gear, the pickup screen could be clogged with debris. The other thing that happens on big blocks that sit for long periods of time is that valve guides will rust up, this can lead to a stuck valve that breaks or badly bends a push rod. If the push rod gets disengaged from the lifter, the lifter will pop up out of the housing and no oil pressure will result.

Dave
 
Thanks guys. Tomorrow I'll pull the distributor and see what's going on.
 
The hex fitting on the oil pump drive shaft will also sometimes break off, but that is a rare failure.
Dave

I had this happen to me after doing a oil change, check the hex on your dist. gear shaft. Damedist thing I ever saw! Good Luck
 
As a follow up. it is usually easier to rotate the crankshaft to TDC. That way you can reinstall the pump drive shaft per the FSM so you can get the timing close.

Dave
 
Ballast resistor,,,,,,





:rolleyes:
 
Are you sure you didn't have oil pressure? Jezebelle's oil light came on while driving, a couple times. Scared me to death. Shut her down and pilled off the road. Oil level OK, all looked good. Restarted and no engine noise even though the light stayed on. Then it went off and all was well.
 
Are you sure you didn't have oil pressure? Jezebelle's oil light came on while driving, a couple times. Scared me to death. Shut her down and pilled off the road. Oil level OK, all looked good. Restarted and no engine noise even though the light stayed on. Then it went off and all was well.
Completely sure Will. The start up clatter didn't go away after a few seconds and when I pulled the dipstick the oil level was just like I pulled it cold.
 
Completely sure Will. The start up clatter didn't go away after a few seconds and when I pulled the dipstick the oil level was just like I pulled it cold.
Startup clatter?
To make a summary statement that piles onto what the other guys have said:
Oil pumps just don't fail from 1 day to the next whilst sitting. They may lose prime, or something else. But they don't quit like a lightbulb (under normal usage).
And the #1 rule in diagnosing a pump - it can't move fluid if it cannot get fluid.
 
pull the distributor and spin the oil pump drive until you feel resistance. If you never get resistance, meaning the oil is flowing, something is broken.
 
Told ya's...
hat-gif.gif

:lol:
I'll add my two cents... The immediate first thing I WOULD do is to pull the pump and go from there.
 
Used to have to prime my pump every time I changed the oil. I used petroleum jelly to prime the pump, and that worked nicely, but pulling the pump after every oil change got OLD.

Then I started running 10-30w instead of 10-40w. Haven't had to prime the pump since then.

I had this epiphany after reading up on how Mopar (Veertman) designed the oiling system for lower viscosity oils and that these really are to be preferred over the popular 10-40w or worse, 20-50w stuff.

One of these daze, I WILL pull the oil pan and replace the pickup screen and such. But so long as Tilly ticks along w 10-30W Rotella T5, I'm not going to disturb a happy status quo.
 
Chris, have you been able to zero in on the oil pressure problem yet?
 
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