Water getting in oil

mdevinc2001

Recruit
Joined
Mar 28, 2004
Messages
2
Here we go again. Spring time and I am starting to get in the boating mood. Last year I had a problem with water getting in the oil. I still have this problem. I parked it for the winter vowed to take a "break" from it. Here is a list of things I have checked or replaced. By the way, I have a 93 Chris Craft with an OMC Cobra 5.8 351 windsor. When I first noticed it I took of the intake and saw that the underside of the manifold where the thermostat houseing bolts onto was cracked. I thought, hey there is the problem. So I replaced it with an Edelbrock performer. Got it all back on and still did it. SO then I broke down the heads, had them pressure tested, planed, and new gaskets. Same thing. I then replaced the exhause flappers thinking the problem was water coming back in. There were worn, so it was a long shot. Same thing. This was all last year and now this year I have already tested the exhaust manifolds. I did a home pressure test with a water hose, blocked off the plate where the riser bolts onto, and tested it with water at my house pressure of about 85 psi water pressure. At first, I just had one gasket on and it leaked really slow so I put another on thinking the water pressure was too much for that environment. My dad was a mechanic for 15 years and he said we should test them with air. Is there a difference? The book says as long as they hold 10-15, they are fine. 85 is sooo much more, i don't know how I could not test them correctly. Could the water be getting in from the connection on the risers where they bolt to the manifolds? How much water pressure is going on when the boat is idle and running at about 2500 rpm. Last year I could sit in the driveway on the muffs for an hours and have no signs of water in the oil. As soon as I put it in the water and go about 1500 rpm, that is when we get the water. You can pull the dipstick and see it 15 seconds after going. We did have the engined pulled to replace the coupler where the drive shaft goes in on the engine. The rear end was pulled out. Could water get in the ingine that way? I didn't see any other way water could get in the engine other than the intake hose to the water pump. We also replaced the impellar as it was out, and was wondering if that could cause an increase in water pressure going out. That is when we started to notice the water in the oil after it was pulled. <br /><br />Any help would be great. The local marinas don't have any way to pressure test the manfifolds, that's why I did it myself with the water. I guess what I need to do next is put the risers back on and seal it really good and try again. <br /><br />Thanks,
 

Danny_Ocean

Seaman
Joined
Feb 8, 2004
Messages
64
Re: Water getting in oil

Seems like you've tested everything, but have you pressure-tested the engine block?<br /><br />D. Ocean<br />Pompano Beach, FLA
 

yoced

Petty Officer 2nd Class
Joined
Oct 8, 2003
Messages
142
Re: Water getting in oil

best test is to put 20psi air into the water passages of the manifold. Dunk it in water while it is hooked up this way. You will find any small leak this way. Only thing: you should use a rubber gasket instead of a standard riser gasket.
 
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