milky oil!

[CV16]

2000 5.0 GL PEFS
4012042852
3869056
So, the 1st time out this season I overheated. New pump is in, water problem solved there. Now it seems I have water in my oil. I read somewhere about a gasket that should be changed after an overheat. Would said gasket allow water into my oil? Any help here would be great. I'd sure like to enjoy the boat for a day with the family. So far it's just been work on it. Bought it at the end of last season and all was good. The motor was drained over winter, and yes, all plugs were removed. I'll have to go get my gauge for a compression test, but was holding on to hope that this could be an easy gasket type thing.

 

[ericga]

Most likely the gasket between the riser and manifold on both sides of the engine.

 

[CV16]

Yup, found it after my rant. Poor connection here. Can't seem to search anything. Would those gaskets allow water into the oil?

 

[cptbill]

don't know exactly what engines were talking about but after an overheating (depending on how hot and how long it was run) compression test is what I would do first, I've seen a lot of cracked heads after over heating

 

[CV16]

Maybe a touch over 200? on a 5.0. Not even a minute at that.

 

[cptbill]

When you pull the plugs to do the compression test look for water in the cylinders. Still what motors and how old, salt or fresh water operation?

 

[ericga]

Yes they could leak water in the oil through the exhaust.

Where do you see the milky oil and how much water are we talking about?

 

[CV16]

I started the post with the motor info, but here it is again.

2000 5.0 GL PEFS
4012042852
3869056

Fresh water only. I bought it with 28 hours last season. It now has 69 hours on it. I ran to Harbor Freight and bought a cheap pump and got about 1 quart out. The hose keep collapsing. The oil I did get out is milky. We are having a heatwave, so this is going to sit til the weather get a bit cooler and I get a better pump or better hose.

 

[Bondo]

Ayuh,.... Is this a Chevy 5.0l, or a Ford 5.0l,..??

Who winterized the motor,..??

How was it winterized,..??

The only way the exhaust riser gasket can put water into the oil, is past the piston rings,....

 

[CV16]

Chevy 5.0. I winterized it as I have done my other boats for the past 25 years. I went to the Adults only section and found the section covering the Volvo Penta and followed that. Just removed all of the drain plugs, drain and fill the lower unit and so on. I worked at a marina a few years back and that's all we ever did.

 

[CV16]

I didn't know Ford still made marine engines in this century.

 

[CV16]

Water in 4&6. Compression is 132- 138 on all. The riser gasket is shot on that side, other side looked ok. New ones on the way.

 

[WIMUSKY]

"If" you still have milk after changing said gasket, you may want to change head gasket(s).......

 

[CV16]

Was thinking about that, but it runs so smooth. I'd think it wouldn't run good with a blown head gasket.

 

[WIMUSKY]

Was thinking about that, but it runs so smooth. I'd think it wouldn't run good with a blown head gasket.

I had a blown gasket, but hydro locked when starting, so it was slow to turn over. Ended up bending a push rod and screwed up a rocker. It ran good. Just had milky oil. That's how I found out about the bad head gasket....Clean plug and washed cylinder...

 

[HT32BSX115]

Was thinking about that, but it runs so smooth. I'd think it wouldn't run good with a blown head gasket.

Howdy,

Leaking riser gaskets can allow a very small amount of water though open exhaust valves, into combustion chambers, past the rings and then into the crankcase.

I had a similar problem with my formerly installed OMC 460. It had leaking riser gaskets on both sides and would allow water into the exhaust manifold immediately after shutdown.

If I tried a restart right away, It was enough to make the engine NOT crank or crank VERY slowly. If I tried to start it more than about 30-45 min after shutdown or the next day etc, it would start normally. (indicating that the small amount of water had leaked right past the rings)

It then ran normally after that. I never had "milky oil " though because subsequent running evaporates all the oil out!

If you think about it (with leaking riser gaskets) , we are talking small amounts of water on the order of maybe 1/2-1 cup in the riser.....and any leaking water goes out with the exhaust during running..........

Immediately after shut down, the water level in the water in the riser starts dropping right after the engine stops turning. ......... while it's dropping, *some* water leaking past the gasket(s) ends up in the exhaust manifold(s) and in turn, into whichever ex valve that happens to be open.

The amount will usually be table spoons (which can still cause a hydrolock if you try to crank wight away)

On the other hand, if a manifold is internally cracked, there's more water that can leak in after shutdown. (minus the amount that evaporates in the hot manifold)

Also, you might consider a pressure check on your entire cooling system before you pull heads.

If you suspect a cracked ex manifold, it might be a good idea to pressure check each manifold. You can do this by making a blockoff gasket to completely seal the manifold-to-riser connection so you can pump the manifold jacket up to 15psi or so and see if it holds.

A block-off gasket can be made out of a piece of sheet metal drilled to match the bolt pattern of your riser/manifold bolts. Then just use some regular gasket material and any gasket sealant of your choice to seal between the sheet metal/gasket/exhaust manifold connection.

Bolt the riser back on to clamp the connection together and connect your gage/valve and air compressor. I was able to pressure up my Mercruiser 7.4L exhaust manifold to 15 psi for hours this way. You just have to ensure you have a good clean flat surface on your manifold/riser connection.

Regards,


Rick

 

[CV16]

I'm giving up on taking it to Arkansas next Friday. I know you're right. I need to do a good check of everything. With the heat and work, I just won't have the time to do it. I still might just try these gaskets and see how it goes, I could have 2 test runs before we leave!