No oil pressure

[ianpala]

So heres the deal... I'm a dumbass. I was in a bad mood tonight and to make things better thought id rip it up on the highway with my 1971 351. Unfortunately i didnt realize i had accidentally shifted down to 2nd and my engine got a little hot. I then pulled over and let it cool off for a minute. Afterwards it drove fine, but sometime after that my oil pressure gauge wasnt getting a read at all. The needle was all the wat to the left or low side. The engine was running smooth and great but it now had a new different sound to it. I wouldn't call it knocking, more like a chopping like ch-ch-ch-ch. I have no idea what it could be. Any ideas?

 

[comanchepilot44]

That would be lifter noise from them collapsing due to lack of oil pressure keeping them pumped up. I'll bet your oil pump drive shaft is twisted and broke. That was the failure mode on my engine. Happened at freeway speed. Made terrible noises that steadily got worse. No knocking just a threshing machine sound.

 

[marks73]

Get a gauge and check the pressure. If still low, do as recommended above stating with the oil pump drive shaft. Do not over rev the engine until you know. It takes very little to wipe bearrings.

 

[ianpala]

Thanks guys, looks like she has no pressure and i snapped the shaft, not looking good, hope i dont need a rebuild.

 

[marks73]

I would do a very good system oil flush. Use a drill motor to run your oil pump and flush the bearings and journals.

 

[ianpala]

Thanks for the advice, i'll make sure that gets done.

 

[auron73mach1]

Hope you didn't wipe a main bearing that would make you lose pressure as well ... ask me how I know (freaking dodge)

 

[marks73]

Much of this depends on how long the engine was starved. You could, of coarse, drop the pan and check some bearings before you go any futher so as not to waste money. For the amount of time it takes to do. That would be my recommendation. If all looks good. Then flush it.