Milky oil

[Corvettedude2]

Hey everyone about 4 years ago I posted here about milky oil in my 2007 stingray with a volvo penta 3.0. It was under a different account I was unable to access. Yall were very helpful back then and helped me trouble shoot with pressure testing the cooling system and compression test. I pressured tested the block and it held 20 psi for like 8 days so yall determined I should change the oil and try it again and it never had a milky oil problem again i posted all about that outcome years ago. Fast forward 4 years to now and the boat has been fine this whole time and been out 3 times this year and been fine until today. Took it out for the fireworks and I always check the oil when I get home and put it in the garage and there it is again milky oil. What could cause this intermittent milky oil problem? It used to "diesel" bad when I shut it off and I remember someone here said that could cause it but yall said to allow it to idle for a minute before shutting it off and I've never had a diesel or run issue since I started doing that

 

[Corvettedude2]

Update...out of curiosity and the fact I already have my test hoses already made from last time. I went ahead and started my pressure test. Block was drained of water and filled with 15psi. Will update everyone tomorrow after work to see if it lost any, if it did I will check all my connections with soapy water to see if there are any leaks and try again.

 

[Scott Danforth]

pull the manifold, look for evidence of rust trails from the manifold leaking water

 

[Corvettedude2]

Checked the boat on my lunch break. The block has held 15psi all night long. Thank you for your suggestion scott. Is it possible to pressure test the manifold on the boat? If I could somehow block the water part off on the riser I could check that whole system.

 

[cptbill]

Sometimes things expand and contract at different rates, I've herd of cases where people run there engine and get it up to temp, shut it off then launch it into cold water and all of a sudden there's a leak . Like Scott said pull the manifolds and risers and look for rust trails

 

[Corvettedude2]

When you take the riser off is there supposed to be any sort gasket there? Seems like last time I had it off there was just a metal plate with only one hole. I can see where a small amount of rusty water has been leaking outside from the riser manifold seal if its leaking there I'm sure it could very easily leak inside too. Any thoughts? And why does that metal plate only have one small hole instead of letting it flow out for all the jackets? Does it restrict the flow to build up pressure or something?

 

[kenny nunez]

There is supposed to be a gasket on both sides of the plate, the small hole is a air bleed hole to the riser.

 

[cptbill]

That metal plate is the gasket if it's original equipment VP, do your self a favor and use an after market gasket that's not metal. That metal gasket can and will fail making you think you need manifolds and risers. Had it happen on a couple different boats

 

[Corvettedude2]

So just do away with the metal plate and use one gasket or gasket both sides? I may order some gaskets and try this since I now see that water has been leaking from it before I pull manifold I'll order some spares too incase I end end pulling the manifold

 

[Scott Danforth]

look up the right gasket by your serial number.

 

[Corvettedude2]

And yes it's all factory vp setup. One corner of that metal plate sticks out like s little tab and it has red paint on it. It was clearly painted red after the plate was installed

 

[Corvettedude2]

Just looked up a schematic it does have a gasket on either side of the metal plate. I guess I'll replace it what's everyone's opinion gasket and do away with metal plate or go with factory setup?

 

[Corvettedude2]

Something kinda odd seemed to happen tonight. It has held that 15psi for days maybe lost a half a psi of that. Anyways I tipped the boat up and drained all the oil to get all that milky crap outta there and went back about 2 hours later to see if i had locked the garage door and I looked at the pressure gauge and looks like it lost a pound or so. Released the air pressure and refilled to 15 again. Could all that moving around and me getting in and outta the boat affect the pressure a little or think it's just that cheap gauge got bounced around a little bit? Guess I'll recheck tomorrow. I'm paranoid about everything so I immediately thought since my dipstick was out and the fill cup was off and the oil drain plug was out that maybe there was a crack or something and now its allowing it to lose pressure quicker. But it's probably overthinking I'm sure that dipstick isint air tight and that fill cap has a PVC valve on it. Isint that what a pcv valve does is let pressure out of the crank case?

 

[Corvettedude2]

Havent had a chance to mess with it anymore due to a death in the family. But How long should it hold pressure? It holds the 15 psi for about 24 hours. Then slowly loses it probably 5 psi within a week.