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Hi -
I'm new to this website and performance boats. I just picked up a jet boat with a Chevy 454 that has Hardin through transom exhaust logs and after two time at the lake we now have a small amount of water in the oil. Are there any other things that can cause this besides a headgasket or cracked block? Any insight would be appreciated. Thank you.
 

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jetboataholic
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Hi -
I'm new to this website and performance boats. I just picked up a jet boat with a Chevy 454 that has Hardin through transom exhaust logs and after two time at the lake we now have a small amount of water in the oil. Are there any other things that can cause this besides a headgasket or cracked block? Any insight would be appreciated. Thank you.
How much is a "small" amount?:)eh:)

Welcome to the boards.:D
 

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E-7 Sheepdog (ret)
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Sources for water.

Excessive block pressure (from a wide-open cooling water controll valve), resulting in:
Blown head gasket, blown intake gasket (most comon (weakest point))
cracked block or head (rare).
leaking valve guide or exhaust manifold (would prob. hydraulic the engine tho).
Condensation, from excessively cool engine (see first leak source)

Now, yes, hiow much water?
How warm or cold is the engine running, at idle AND at cruise?
 

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Discussion Starter #5
the engine isrunning pritty cool about120 at idle and crusing at about 130 thanks for the quick replys
 

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Grubby theres a diagnostic saying " when you hear hoofbeats think Horses not Zebras" ,very likely its something simple like missing exaust flappers (for example), whats very important is , has the oil level on the stick increased or is the oil a little milky ? could also be a simple cold running/condensation problem too ! Post up a pic of the oil on the dip ! Tom
 

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Grubby theres a diagnostic saying " when you hear hoofbeats think Horses not Zebras" ,very likely its something simple like missing exaust flappers (for example), whats very important is , has the oil level on the stick increased or is the oil a little milky ? could also be a simple cold running/condensation problem too ! Post up a pic of the oil on the dip ! Tom
I'm not sure if you've nailed the problem, but I really like this quote!!
 

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jetboataholic
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Grubby theres a diagnostic saying "when you hear hoofbeats think Horses not Zebras" ,very likely its something simple like missing exaust flappers (for example), whats very important is , has the oil level on the stick increased or is the oil a little milky ? could also be a simple cold running/condensation problem too ! Post up a pic of the oil on the dip ! Tom
That's how it is here in KY. "Horse Capital of the World":D
 

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well guys i have several thihgs to look into now i am curios how much pressure the pump (berk 12-jg) will put on the cooling system also i had the distributer out and it looked pritty milkey in the lifter valley then i checked the dipstick and you could barley see evedince of water down in the pan.
 

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"Try it Now!"
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I always fight that problem with my Olds, and finally just about got it licked between too cold operating temps to PCV / ventilation problem. I found that if i run 180 at idle, the motor is too damn hot. YOu have to remember that there's no thermostat usually, and that water is reaching 180 degrees in a hurry, as opposed to chillin in a radiator. My motor for some reason is happiest near 150 at idle, 120 while driving. A true oil temp guage would probably tell a different tale.

My nickel's worth of free advise.
 

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Pressure testing

It is quite simple to block off the water inlets/outlets and do a REGULATED pressure test of the engine cooling system.......Regulate down to 12 -15 lbs and pressurize the system, (engine), and see if it holds pressure or not.........If it does, do the same with the exhaust logs........If everything holds 15psi pressure you don't have any leaks. If it leaks down, start listening for escaping air..........You should be able to prove it is tight, or find the leak.........MP
 

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GrubbyG,
First thing I suggest is to drain all the oil/water/milkshake out of the engine. watching what comes out will help isolate the problem. plus you don't want to leave the water in the crankcase.

If serious water is in the oil and it has been run, it will all be a pretty thick, foamy consistancy, with that awful biege color.

If just some condensation, it will drain out looking the normal "black" color, with maybe a swirl of the biege color on it.

At any rate, the milkshake oil does not lubricate the engine properly, so don't run it with the milshake oil.

At the marina used to work at, the typical process was to get the milkshake out, next see if we could see an obvious reason for the water. We pressure test the block and manifolds, etc.

Then with fresh oil and filter we would run the engine to see if the problem repeated itself. In the case of a jet, I would put a pressure gauge on the block cooling system, you want to see only 15-20 psi. more and you are prone to blow water past the intake gasket.

The causes of water in the oil I saw were:
rain water through the carb (check to make sure water cannot get into carb when boat is stored.)
bad exhaust risers (snail) (I boat on salt water so happens alot)
bad head gasket (usually on SBC only)
bad intake gasket
intake valve not opening, causing exhaust to suck water in from manifold while running.

Doug
 

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Relief valve

VERY important........The oil pump relief valve is in the lowest portion of the oil pump. If you allow the milkshake to sit in the engine, the water will separate out and accumulate in the area of the relief valve, causing it to rust in place and not work. The first sign will be the blown oil filter "O ring"...The second sign will be a huge mess in the bottom of the boat, and the third sign will be you pulling the engine to fix the rusted, stuck relief valve. SO, get the milkshake out and run some good oil through the motor as soon as possible...........MP
 
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