Water in oil AGAIN

[LinkAmerica.net]

Hello,<br />I have a 90 OMC Cobra 5.8L engine with an OMC stern drive. Last year I was getting water in the oil. I took it apart this year and found I had a cracked intake manifold. I could not find a replacement so I replaced it with an Edelbrock Performer intake. The crack in the intake was letting water get into the well where the pushrods are on the 351. Got the intake on, sealed everything, checked everything out, runs fine. Put it on the muffs and changed the oil and filter and it had no extra fluid in it for about 30 mins of running on the muffs. Took it to the lake and ran it for an hour and a half and brought it back home, it has twice as much fluid on the dipstick as it was before. Why would it run fine on the muffs and not in the lake? What would be the difference, maybe more pressure in the lake because your running higher rpm's? Is there any way water could be getting into the engine from the transom or is the hose that comes from the impeller the only access for water? Also, could it be a water pump problem? Is there any access water can take to get to oil from the pump or is it just a bolt on accessory? I believe the intake cracked because of excess heat. Last year the engine ran for about 10-15 minutes with absolutely no water in it after a year of sitting. So maybe a busted head gasket? Maybe a cracked block or head? <br /><br />Any help would be great.<br /><br />Mike

 

[mvaughn]

Re: Water in oil AGAIN

After battling this problem myself! I suggest you pull the engine, have everything magnifluxed, will most likey need to have the heads and block milled, if the're salvageable? 10-15 minutes with no coolant? Complete rebuild. Good Luck

 

[jeremyp111]

Re: Water in oil AGAIN

Are you getting hydrolock? Do you ever try to start the engine and it doesn't turn? If so, then check your spark plugs for water.<br /><br />I just went through this same problem with a 1988 OMC 5.7L. The oil in my engine looked like a coffee milkshake. Maybe my experience will help you. Last year I started getting water in the starboard cylinders. I replaced the riser gaskets, which turned out to be shot. I thought I had fixed the problem, but it turned out that I was still getting water in the the number 4 & 6 cylinders. I pulled the exhauset manifold, intake manifold and head. I found a pretty damn big crack in the head. Put a new head on and bolted the rest back together and all was well. No more water in the cylinders.

 

[akriverrat]

Re: Water in oil AGAIN

if you get it fixed and don't allready have closed cooling system you might want to take the time to install it. aluminum intake bolted to cast iron heads and raw water cooling create condition for electrolysis that will eat up the manifold and put more water in the oil.