35fountain

2 years ago I did a water pressure test on my engine and found water leaking from casting in the exhaust port. I changed the heads. 40 hours later on the motor I noticed the milky oil in the breathers and under the valve covers again. Oil in crankcase clean no white stuff. I pressurized the water passage to 20lbs pressure. It seems to be dropping 1/2 lb per 15 minutes. I am noticing the oil level in the crankcase has gone higher on the stick. Is this a crack in the head, head or intake manifold gasket not sealing properly. How do I find this.. The exhaust system is bypassed and not part of this pressure test. Should I pull the heads ??
any help would be appreciated
Thanks

Ted G

iTrader: (1)

My bet would be on the intake gaskets. Unless the portions around the water jackets were coated with Merc Perfect Seal as specified in the manual they will leak. And a lot of people don't do that.

35fountain

I think you are right...I just pulled the intake.. Just before I did my pressure test I filled the intake with water. After removing the intake I found fresh water lying on top and around the white sludge which was only stuck to the bottom of the air gap intake and top of the oil galley pan. None in the lifter galley. I doubt I would see fresh water after it been sitting for 5 months like this. I noticed that one side of the intake gaskets were lower not sealing perfectly against the head. It must have slid down while I was installing the manifold. I didn't really care for those gaskets. Hardin Marine..I'll try fel pro this time I will post some pics
Thanks

US1 Fountain

iTrader: (1)

I had this same problem on my last boat with a B&M blower intake. Within a few seconds of running, I'd gain a qt of water in my oil. Had my heads tested and even resurfaced, pressure tested the block with a torque plate, and neither looked to be the culprit. Reassembled once again and had water again.

Turned out the intake never pulled down tight enough with the 2-3 rounds of torquing the intake bolts down. I never rechecked the 1st bolt to see if it was tight once I got to the last bolt of the last torque round. Just called it done after that last go around. If I had, I would have found out it was only finger tight. Accidentally stumbled across that after many weekends of lost boating and a grand in $ spent.
I then replaced the gaskets once again, but this time I kept going around the intake till all bolts were holding torque. I believe it took 8-10x going around till the intake pulled down.
Felpro gaskets used every time.

My stock intake was never a problem, just the B&M intake, and it checked out flat and square. Who knows

35fountain

I usually check the torque 4 to 5 times and then again after a day of running. If you look at the pics you will see that 1 side of the heads the gasket looks like it moved down. 2 years ago when I found the head had sprung a water leak from the exhaust port I had other bad symptoms like rust on the spark plugs.. This time no rust, the plugs look normal. I am pretty sure it was the intake gasket..
thanks

35fountain

I usually just put some high temp silicone. But now I will use the merc pefect seal. Do you put it on the head side and the intake side also ?