No Oil Pressure In My 300

[azblackhemi]

Chris, have you been able to zero in on the oil pressure problem yet?

Not yet Bob. I changed the oil and filter but now can't get it started. Not sure why. I had the distributer out put it back in and wouldn't start. Went back and did it by the book bringing it to TDC and making sure it's in right but still no start. I'm pretty sure the filter didn't solve the problem though because after a lot of cranking the oil didn't pump up at all. Now I'm just waiting until I have time to pull it all back apart. Probably will have to replace the pump.

 

[1978 NYB]

Not yet Bob. I changed the oil and filter but now can't get it started. Not sure why. I had the distributer out put it back in and wouldn't start. Went back and did it by the book bringing it to TDC and making sure it's in right but still no start. I'm pretty sure the filter didn't solve the problem though because after a lot of cranking the oil didn't pump up at all. Now I'm just waiting until I have time to pull it all back apart. Probably will have to replace the pump.

Give it a squirt of ether and see if it fires. If it doesn't fire probably an ignition problem.

 

[commando1]

first thing I WOULD do is to pull the pump and go from there.

 

[1978 NYB]

I made a tool with an old distributor shaft and mounted it in a drill and spun the oil pump with it to check and see if I was getting oil to the top of the engine. I'm sure you can get a cheap priming tool. I don't see any reason that the pickup is plugged and since it ran previously I don't think the pickup fell off the pump.

 

[twostick]

I made a tool with an old distributor shaft and mounted it in a drill and spun the oil pump with it to check and see if I was getting oil to the top of the engine. I'm sure you can get a cheap priming tool. I don't see any reason that the pickup is plugged and since it ran previously I don't think the pickup fell off the pump.

They can crack where they thread into the block and suck air causing loss of prime but it's pretty rare unless the oil pan had a close encounter with a speed bump or a wayward jack.

The pickup can get plugged if the stock nylon coated timing gear sheds its teeth.

Something else just occurred to me, the bypass valve could be stuck open in its bore or the spring could be broken. Easy to check without getting too dirty.

Does it have an oil pressure gauge? If the pressure was normal at idle before, it would be a very rare occurrence for it to be the pump itself. Short of the primary rotor shaft breaking, there really isn't anything to keep it from pumping if it turns and it has oil. It would have to have had a mfg defect because the intermediate shaft would normally yield before the rotor shaft would.

Kevin

 

[66Newyorker]

Not sure but in 70 did the camshaft gear have nylon coated gear? If this is the case your pickup screen could be clogged. Your pump is fine. Pull the water pump housing and the front cover. Just a thought!

 

[Davea Lux]

Not sure but in 70 did the camshaft gear have nylon coated gear? If this is the case your pickup screen could be clogged. Your pump is fine. Pull the water pump housing and the front cover. Just a thought!

You can also pull the distributor and look at the upper timing gear from the back side which is less work. If it still has the plastic gear, now would probably be a good to to change it. Its 50 years old and the plastic is probably very brittle.

Dave