Oil Consumption

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fpc310
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Joined: Wed Sep 05, 2018 5:39 pm

Oil Consumption

Post by fpc310 »

I realize that no oil consumption is normal. My Stbd 318 consumed about 1.5 quarts after 12 hours of running. I know the previous owner only ran this boat twice a year at most and that was at 2000 rpm or less. What’s the worst case / best case for this motor? I plan to check compression soon, but I’m looking for suggestions on how to get a few more years out of this motor.
Todd
1983 32’ SedanFlybridge
Twin 318 Chryslers.
Marblehead, Ohio
Fastjeff
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Joined: Sat Jul 12, 2014 5:06 am
Location: Rock Halll, MD

Re: Oil Consumption

Post by Fastjeff »

Oil's cheap. Long as plugs aren't fouling, why not just keep the level up?

You might have worn out intake valve seals, that can be changed without removing the heads. It's a messy job.

Jeff

PS: Don't buy into any miracle "snake oil" cures. They seldom work.
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington
honestcharlie56
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Joined: Tue Jul 19, 2016 8:27 pm
Location: Lake Charles, LA

Re: Oil Consumption

Post by honestcharlie56 »

Start with the easy!

1) Fill the boat up with gas and go run her hard, should be able to get the boat planed out and see no more than 4400 RPM at WOT. The problem isn't as prevalent in gas engines, but I used to work on diesels all the time that had been idled around and were developing problems.....run the piss out of them and all the sudden they ran better.

2) Do you see any smoke on start up? Sometimes valve seals can show themselves worn as smoke on start up?
1990 Marinette 32 Sedan Flybridge "Hubba" Lake Charles, LA
Twin Chrysler 318's
Fastjeff
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Posts: 1521
Joined: Sat Jul 12, 2014 5:06 am
Location: Rock Halll, MD

Re: Oil Consumption

Post by Fastjeff »

Good advice: If it won't behave, beat the hell out it! Mechanical things need to know who's boss.

I'd also recommend pulling the plugs AFTER running it hard, both to inspect them from color (a few may be darker than the rest) and for your compression test. You can borrow a tester from AutoZone if you don't have one.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington
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