Merc Cruiser-water in oil

[frankjenia]

I have a 1976 Merc Cruiser, Ford 351 with internal (antifreeze) cooling. My oil is turning tan colored after running the engine for only a few minutes in the marina and not moving it. It appears to be getting water in the oil, however the antifreeze is not ?noticeably? going down. The cylinders ?appear? to be dry (no ?volumes? of water or wet spark plugs). I have RECENTLY put on new exhaust manifolds and risers. Is there a way to tell if the water is Ocean water or antifreeze? Also how could water get into the oil from the exhaust manifolds?
What could be the most likely cause of this problem?
1. Cracked block
2. Bad head gasket
3. Exhaust manifold/riser issue
4. Hose hooked up wrong
5. ?????

Would a compression test tell me anything?
Could there be any way salt water is getting in, (new risers)?
Also if I have to pull the heads, would you recommend the valves done at the same time? Compression before new manifolds:
1=132, 2=125, 3=132, 4=118, 5=125, 6=127, 7=135, 8=130.
Thank you for your help, Frank

 

[jerryjerry05]

Re: Merc Cruiser-water in oil

Do you have an oil cooler in the water intake line?They can leak and the water gets in the system.If the risers weren't sealing it could be comming in from there.It leaks down past the valves.Don't remove the heads if the plugs are running the right color and it's not missing and no water in the cylinders.
Good luck,J

 

[dubs283]

Re: Merc Cruiser-water in oil

taste the oil, is it salty?

 

[frankjenia]

Re: Merc Cruiser-water in oil

Thanks, I let it set a while and the oil rose to the top, drained it off then tasted it and it still tasts like oil.

 

[frankjenia]

Re: Merc Cruiser-water in oil

Do you have an oil cooler in the water intake line?They can leak and the water gets in the system.If the risers weren't sealing it could be comming in from there.It leaks down past the valves.Don't remove the heads if the plugs are running the right color and it's not missing and no water in the cylinders.
Good luck,J

No cooler in line. Several plugs had white annodes so I think it might be coming from the exhaust risers but they don't appear to be leaking from the outside. I put all new gaskets that the dealer sold me on, with 2" metal spacers on them.

 

[jerryjerry05]

Re: Merc Cruiser-water in oil

The internal parts might not be aligning take them apart and make sure the mating surfaces are flat/smooth.Then reassemble using a good sealer,not the silicone type.J

 

[frankjenia]

Re: Merc Cruiser-water in oil

Thanks, do you (or anyone) know if the Exhaust Elbow Plates should be mounted with the raceways facing up or down?

 

[frankjenia]

Re: Merc Cruiser-water in oil

Took a nice boat ride today and yes it was Salt water getting into my oil from the "exhaust" manifolds. I decided to change "all" the manifold gaskets and noticed the new elbow ones were much thicker then the ones the dealer originally sold me forthis application. So the conclusion is that salt water was leaking past the other Blocking elbow gaskets and getting into the exhaust manifold.