Head Gasket / Milky Oil

[achris]

Seen manifolds crack when the water started flowing again after it was stopped and the manifold got very hot. Sudden cold water inrush and crack. Was very common on the old 165 before they reversed the water flow... It may also have cracked earlier and just not been open enough to be noticed... A bit of use and the crack opens up slightly...

But that's just a guess...

 

[HT32BSX115]

but how would the manifold crack in the middle of the summer? There was no water in the oil from may till the end of July

It could have rusted through if it was really rusty to begin with. Do you or did the previous owner operate in salt water?

 

[Jon1229]

It could have rusted through if it was really rusty to begin with. Do you or did the previous owner operate in salt water?

Yes we both used it in salt water. I’m hoping it’s nothing serious and I’m somewhat confident that it’s not because there was no oil in the water before I replaced the head gasket and there is after I replaced it. I’m hoping it’s just a user error. When I put the bolts into the manifold to secure it to the block and the bolts into the exhaust elbow securing it to the manifold I didn’t use any sealant (I didn’t think those screws ever got it) but maybe I should use it when I put it back together? I’m putting a new manifold gasket and elbow gasket in tonight

 

[Jon1229]

Seen manifolds crack when the water started flowing again after it was stopped and the manifold got very hot. Sudden cold water inrush and crack. Was very common on the old 165 before they reversed the water flow... It may also have cracked earlier and just not been open enough to be noticed... A bit of use and the crack opens up slightly...

But that's just a guess...

Thanks! Is there an easy way to test the manifold alone? Should I test it before I put it back together or after?

 

[achris]

Make a block-off plate for the water passages at the elbow end and pressurize through the hose at the front.

Chris.....

 

[fishrdan]

Thanks! Is there an easy way to test the manifold alone? Should I test it before I put it back together or after?

Pressure test as achris said. Or, fill the manifold's water jacket with acetone, and watch for leaks. Shine a flash light up into the intake/exhaust ports.

 

[Jon1229]

Thank you everyone for your help! This weekend after pressure testing the block and the manifold I decided to undo everything I did when I put in the new head gasket, replaced the manifold gasket and elbow gasket, cleaned all surfaces again, cleaned bolts and put more permatex than last time.. etc.. don’t know what the solution was but there’s no water in the oil anymore! What a relief. Unfortunately now the idle isn’t as smooth as it was, engine seems to rock a little bit, but it’s also idling around 500-600 rpms which to me seems low. When I adjust the idle it jumps from 500 to 1100 with no middle ground. Oh well. Today I’m going to replace all the spark plugs and take it out for a while. Thanks again everyone

 

[Scott06]

Check manifold gasket and carb gasket for vacuum leaks can spray starting fluid on surfaces and if idle speed increases you have found a leak

 

[Jon1229]

Ran the boat for a while, oil is clear absolutely no water.. finally. After running it for a couple hours the engine also stopped rocking back and fourth and the idle is smooth. A while back in this post I mentioned that the bilge had oil in it and today I found the leak. I don’t know the name of the pieces it is between or on but here is a photo. (Oil looks milky in photo but it was before i ran it for a while to get the remaining water oil out)

 

[achris]

That's either the front crankshaft seal, or the sump gasket.

Chris..........