Edward R. Cozzi

Anybody ever have a small- block oil pump lose its prime?

Crazyhorse

No, I never have.

Edward R. Cozzi

Here's what happened:
The remote oil filter is in an inaccessible location. Salt water sprayed on it from a leaky hose, oil filter rusts and finally sprays most of the crankcase into the bilge. Buzzer comes on, customer sees oil pressure gauge on zero, turns off engine and idles home on one.
I am called in to access situation and find a really nasty mess. I replaced the oil filter, filled the crackcase and cranked that baby up. Buzzer and no oil pressure.

Pulled the distributor and inserted oil priming tool and ran the drill. No resistance- no oil pressure.

Are you intrigued? Shall I continue?

Strip Poker 388

iTrader: (6)

Your saying the salt water rusted thru the oil filter and made it leak How long was it on there ?
I have never lost prime ,maybe oil pumps bad?
Sounds like someone is not keeping up with there maintance

intrigued ? yes lets here some more

Dixie Doug

I would consider the source of your info(rusted hole in the oil filter!!!). If the pump pick-up didn't fall off the bearings have spun.

US1 Fountain

iTrader: (1)

If he turned the motor off as soon as the low pressure buzzer went off, shouldn't it still be ok? Other wise the buzzers are useless. How long could it run w/o before the lifters pump down and start clacking like crazy?

robyw1

It sounds like the oil pump pickup is laying in the bottom of the pan. Or the shaft is broken.

Roby

Crazyhorse

The pump is most likely still submerged in oil unless the engine has a deeeeeep oil pan, in which case you could add two quarts to see if that's the problem.. I'd be inclined to look for a sheared pump shaft. I've seen that happen.

Edward R. Cozzi

It turns out this customer re-started the engine to back this boat into his slip with no oil pressure. I believe this caused the oil pump to lose its prime. Thank God for Royal Purple synthetic oil. These engines have 1100 hours and I have been using RP since 800 hours.
Here's what I had to do to get oil pressure back without pulling the engine:

I put a tee in the oil line coming from the remote oil filter going back to the engine.
Then I ran a 3/8 hose to the drain plug opening to a Jabsco oil change pump. With the engine off I had 20 lbs. oil pressure with this set-up. Then I fired-up the engine and let it idle for a few minutes. All the time the gauge is showing I have 20 lbs. OP.

I revved her up a little with no change. Engine sounded normal and ran smoothly.
I popped it once over 3500 RPM and the oil pressure shot up to 45 lbs. where it stayed. I disconnected the set-up and now my problem is solved.

Thought you fellow gear heads would enjoy this.

robyw1

uhh.... if thats what it took to get the oil pressure back then you need to go ahead and do a tear down. Those pumps must be so worn that their siphon capability is next to nothing. What's gonna happen the next time the oil needs to be changed? It may even do this again if the boat sits a couple of weeks.

Roby