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Blown, OHBA Member
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Discussion Starter · #1 ·
What could be causing this? I don't think it's loading 10 qts of oil in the top. Let off the gas and pres. returns to 70 in the time it takes the motor to idle down. Has this happened to anyone? and how did you fix it? New 496 With HV pump, mech oil pres guage on motor, electric guage in dash, so I know its not the guage.

Thanks in advance
Don
 

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Living in a cage of fear
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The only time my engine did that, the oil pick up was cracked at the entry point of the PU screen. (Milidon)
 

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Remote filter?

If the remote filter is plumbed backwards it will also do that........Flappers closing at higher Rs..........Ray
 

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Sit N' Spin
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1,423 Posts
What could be causing this? I don't think it's loading 10 qts of oil in the top. Let off the gas and pres. returns to 70 in the time it takes the motor to idle down. Has this happened to anyone? and how did you fix it? New 496 With HV pump, mech oil pres guage on motor, electric guage in dash, so I know its not the guage.

Thanks in advance
Don
Maybe too much oil in the pan...windage...crank aerating the oil. Just my $0.02.

Either way it's a sign that the oil pump is cavitating.
 

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mo balls than $cents$
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11,734 Posts
just went thru this, if you're pickup tube is fine, and the cooler is plumbed correctly, its teh oil pan. most milodon type pans don't have the rear tray and the oil can climb the back of the oil pan, crank hits it and poof, oil pressre dives. what kinda oil pan ya got on there????


fyi, hamburger makes a nice cheap oil pan kit for 200 bucks for a jetboat:)bulb
 

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Blown, OHBA Member
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Discussion Starter · #6 ·
?

If the remote filter is plumbed backwards it will also do that........Flappers closing at higher Rs..........Ray
Flappers ? where the hell do they put flappers? :|errI have a dual remote system on this thing. Had the same system on a previous motor and never had a problem. Running Fram HP1 filters with an 8qt truck pan at 1/2 qt over full to compensate for the oil dumped up top. Have restrictors ordered but not instaled. I'll switch the lines today and see what happens tomorrow after work. But with my luck it can't be that simple. If it is IOU a beer or 30, will let you know tomorrow. Thanks everyone for your input.:D
 

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steelcomp was here
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Could also be the pick up is too close or too far from the bottom of the pan. Forget the extra half quart and try seven in the pan. You might be surprised.
 

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Blown, OHBA Member
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Discussion Starter · #8 ·
Strange how identical setups on two different motors can act so different.
will switch hoses and see what happens, then I'll check pickup if that dont work.
Thanks
 

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I agree with steelcomp . Mesure your pickup with the pan , Sounda like you on the bottom and pulling the pan up on a vacume
 

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steelcomp was here
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Strange how identical setups on two different motors can act so different.
will switch hoses and see what happens, then I'll check pickup if that dont work.
Thanks
Don't discount that you're running too much oil. Most pans will work better with less oil than more.
 

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Oil press.

Had it happen to me, oil pump pick-up was too close to the bottom of the pan, it was 1/4" & I changed it to 5/8" & problem solved. some of the cheaper pans can & will flex if the pick up is too close.
 

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Banned
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Why is this sounding like an Olds motor?
Go with 7 quarts, and ditch the Fram crap. Go with anything but.
 

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Mine did this also with a Milodon pan w extreme duty pickup...Even on a run-in stand, so it wasnt oil sloshing around. Tried everything I could think of...more oil, less oil, etc etc. Pulled the engine out, checked the pump, pickup, everything I could think of. Just got a custom made Stef's pan on and the problem is gone. Now it holds 80 psi steady. Now I just need to get the engine back in the boat :D

I'm not saying you need a custom made pan, but it could be the pan causing the issue
 

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Sit N' Spin
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Since it was never mentioned anywhere here, what kind of pan is this that we're dealing with?
 

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Strange how identical setups on two different motors can act so different.
will switch hoses and see what happens, then I'll check pickup if that dont work.
Thanks
Don't just switch hoses and try it.....just make sure they are correct. Many remote filter housings have a check valve in them that will allow ZERO flow in one direction. Its a good way to wipe out a set of bearings in a hurry (been there done that).....there should be arrows cast into the remote housing.
 

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If the remote filter is plumbed backwards it will also do that........Flappers closing at higher Rs..........Ray
I made that mistake once...mine had check valves...and they sealed very well. There should be arrows cast in to the unit adapter and the filter base for direction of flow. Make sure the arrows don't point against each other or you'll be changing bearings in a hurry and possibly more than that.


Make sure the pickup is welded to the pump...not so it doesn't fall off but so it makes a good seal and doesn't suck air when the pump gets spinning.
 
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