milky oil

[Frosty]

I dont like the sound of this at all.Whats the oil pressure? You should not now have contaminated oil, it should be crystal after #4 changes. You should not have oil on plugs. If you have oil on plugs it would be misfiring or at least the exhaust would be smokey?

Check your compressions and oil pressure. The rumbling noise could be very bad, crank!! Are you running this engine in the drive way with the leg up --This will make a rumbling noise, always have the leg down,-- or this could be damage occured when running on 'milky oil'.

[Joe6]

This motor was run hot. Refer to my last post reguading the manifold. Rings are probably welded/corroded to the pistons. As for the rumbling, heat due to water caused big problems.

For your sake I hope I'm wrong, but I don't think I am.

Good luck!

Joe

[crispy]

jack frost, as this is my first I/O, I wasn't aware of the rumbling problem if the leg was up, I lowered the leg and the rumbling was gone. feel a lot like an amateur, but everyone starts somewhere. I just did a compression test and 4,3 &1 all read 120psi, but #2 read 110psi, not too bad a result, a lot better than I had thought. The original spec on it is 140psi, but seeing that the engine is 27 yrs young, I'm rather pleased. A rebuild will definitely be in my future, but I don't think I caused any damage with the diluted oil, as I only ran it for a very short time. thanks again for all your help.

[crispy]

oh yeah, I also noticed no smoke coming out of the exhaust when I ran the engine

[seven up]

crispy, one of my engines also had the milky oil on top of the motor after a short run from the slings to the berth. the milk on top of the engine was coming out a pcv hose at the flame arrestor. the problem was a badly cracked intake manifold and the motor was filled to the top of the valve covers. my point being that it was the intake manifold in my particular case. after the repair the engine was run for the season without further incident (05) and there has been no evidence of a recurrence. Good Luck !

[BJB]

I just had the same problem with a 5.7 Volvo I recently bought. The water in the engine was simply from changes in the weather but the oil was almost the colour and consistency of mayonaise around both oil fills (on the valve covers.) There was also a loud ticking from the rockers due to clogged oil channels.

A close friend is a mechanic so he and I warmed up the engine to 160, drained the oil, changed the filter, put in a 50/50 of oil and atf; warmed it up to 160 again, drained the oil, changed the filter a second time and put in *high-quality* oil. The 50% atf mixture is thin but if you run it a short time there is no harm done and it actually cleans the inside of the engine. The substantial ticking sound took about 1/2 hour of low rev running to clear up but the oil is still very clean and the engine is running very well.

John

[crispy]

bjb, I have now flushed the engine with the mix of atf and oil. it cleared out the water from the engine, I then put the good stuff in and ran it for a good half an hour in the driveway with earmuffs. I am going to take it out on the water this weekend and take a good run before I set her up for the winter and do one last oil change after the boot. the engine ran a lot better and smoother after the flush. Thanks for the tip. And thanks to everyone for the tips, they were greatly appreciated. cheers

[crackerjack]

i have a mercruiser 1985 3.7 L 170 engine. just noticed milky white in the water and a little in the engine oil. would that also be the exaust maifold gasket? could it also be the head gasket? any help please.

[stonebreaker]

You've got to be careful running the ATF in the oil. It is very detergent, and if you run conventional oil normally, the ATF can cause crud to break loose and clog oil passages. If you usually use synthetic, then the inside of the engine should be clean enough.

[BJB]

Hey Crackerjack - I would suggest removing the risers to see if you have any cracks, erosion on the inside of manifold. You might be able to see rust-coloured leaks on the outside as well. Risers are a relatively easy job and it sounds like you could have some leakage. Hopefully you'll catch it quick and aren't in salt water.

BJB

[crackerjack]

just a question..where in the manifold would oil come in contact with the water. also where are the risers? do i have to remove the manifold? worked on auto engines but never a boat, so please bare with me..thanks for your help.

[crackerjack]

i figured out where the riser elbow is. but where would oil and water mix? i have oil in the water and water in the engine oil. when i ran the engine it ran very smoothly so hopfully i'll rule out a cracked block.

[BJB]

There are more knowledgeable guys than me on this site but I'll let you know how water gets in your engine oil (as I understand it). Raw water is drawn through the leg (or seacock) into the system (whether it is a raw or fresh water system). The main point is that it returns through water jackets in the exhaust manifold and/or risers before joining the exhaust gases at the 'tail' of the risers.

When the engine is turned off there is still raw water in these channels. If there is a crack or a leaking gasket in the manifold or riser, the raw water can drain through that crack and ultimately into the engine (through open exhaust valves and into the oil pan). If the raw water is salt water then your main bearings may be sitting in a salt/oil solution - if so the engine will likely soon fail. I believe fresh water damage can be minimized if it is caught quickly. Cast iron manifolds in this type of usage generally have to be changed every 5 years.

You can check this link out as well - http://www.boatsafe.com/nauticalknowhow/cooling.htm

Cheers,

John

[crackerjack]

i'm going to do a pressure test on the engine cooling system. if pressure holds then you should be right. thank you very much. i'll let you know.

[bilgeboy]

I know its a long-shot, but make sure a milking cow has not stowed herself below decks. They can leave a similar deposit, and have you scratching your head for days before you figure it out. If you rule this out, you can MOOOOve on to the other suggestions.

Hope this tickles the ribs,

Mike