Water in Oil

[Elgineddie]

Well I've been chasing this water in the oil gremlin for a bit. Mainly because it seems to come and go. I drain/flush/refill, and it stays clean for a few outings, then, like today for example, I've only run it 2x on new oil, I checked the oil before starting and it's clean, I run it for a few minutes, check the oil and find milk in the crankcase. Never a lot; maybe enough to raise the level on the dipstick 1/8 to 3/16".

So far I've performed/checked:

• Water jacket pressure test = passed; approx 1 hr @ 20psi
• Compression test (dry) = (1,2,3,4) 118, 110, 112, 124
• New AntiSiphon loop = new and mounted as high in the galley sink cabinet as possible

Other info:
Engine is, I believe, a 1977 (071377 code).
Engine always takes ~15-20 seconds of cranking to start COLD. I ALWAYS have the water turned off until after she fires and runs for 10 seconds, and I ALWAYS turn off the water and run it for 20 seconds before killing the engine. Runs great. Sounds great. No leaks anywhere on the engine or water pump.

Before I pull off the side valve cover, pull the head, or buy a new water pump, I have some questions...

• How do I know if the water pump oil seal has failed?
• I noticed the aft spark plug (#4) was wet with what looks to smell and look like water. Indication of a bad head gasket?

Thanks in advance. I promise I read the many posts on this but I can use some clarity because when it happens to you, you become myopic. Apologies.

[Mo]

OK water on a spark plug is going to form a drop, gas won't. It may also look really clean. If you can shine a light at the top of the piston see if it looks shiny, valves might look cleaner than the non affected cylinders also. Is there any steam coming out the exhaust pipe?

As for the water pump seal, an indicator, in my mind is an older pump, with no water dripping out of it. There really isn't much you can do and for some it's a last resort finding water in oil. Sometimes dirt plugs the weep hole and in that case water getting past the first seal may build enough pressure to make it past the inner seal. This would result in water in oil. The few cases I dealt with had a plugged weep hole, that said, they did require a pump rebuild following.

[Elgineddie]

Yes, I do recall some steam rising. And the rear plug #4 is definitely wet with water. Looking into the #4 hole, it's also wet and black. All other plugs are nice colored and dry.

Soooo if that's water in #4, it's a head gasket? Why would a pressure test hold if it's a bad head gasket? (Just general questions now that I think of it...)

[Al Schober]

Curious about your exhaust. Water lift? Mixing can? Some photos would be good.
Keeping those old Oberdorfer water pumps working is more of an issue as they age. I fought with mine for years, finally replaced with the new Moyer pump with ball bearing and a face seal. No more water pump issues. Yeah, they're expensive but so is my time. Time spent working on the boat is time I'm not sailing the boat.

[Elgineddie]

Here are pix front and rear of the pump... unsure the brand.

[Elgineddie]

Here is the anti-siphon loop and the exhaust setup...

[JOHN COOKSON]

Originally Posted by Elgineddie

[*]New AntiSiphon loop = new and mounted as high in the galley sink cabinet as possible

It may not have worked.

To my way of thinking since #4 spark plug is wet water could be getting into the engine from the exhaust system.
Let's see what the pressure test reveals.
If there is a water lift muffler or somewhere water collects that is higher than the engine it is easy to get a siphon started. When a warm engine cools it creates enough of a vacuum to start a siphon. Do you have a flapper valve or some sort of a siphon break in the exhaust?
What make and model is the boat? Maybe someone in the forum has a sister ship and can give you some specific advice on the exhaust system.

ex TRUE GRIT

[Elgineddie]

Okay I’m back at the boat and ran a couple pressure tests:

Exhaust manifold: 30psi for 1 hr = no drop; plugged one hose barb and pressurized the other.

Engine block and pump: 30psi for 1 hr = no drop; Closed seacock and pressurized from the thermostat housing. This should test both in-block water jackets and water pump seals. No drop in pressure. Tested it twice.

At this point I’m at a loss and guessing the long crank times and the water in the anti siphon hose may be the suspect. I can put a drain in the low part of the hose leading to the anti siphon loop and just drain it before cold starts.

By the way, she’s a 75 Catalina 30’

[ndutton]

Following those successful tests it's no longer guessing. The only way left for water to get into the oil is up through the exhaust. The question now is why? I propose a thorough examination of the exhaust system is in order from the manifold flange all the way to the transom.

I think I see a Vetus waterlift. Other Catalina 30 members have them without problems so if it is in good condition I think we can rule out a design problem in a C30 application.

Question 1: is the water incursion preceded by sailing, particularly hard on port tack?
Question 2: Is the anti-siphon fitted with a valve at the top or is it an open loop with a hose attached (no valve)?
Question 3: Do you have the exhaust check valve high in the port cockpit sail locker?

[Elgineddie]

Question 1: is the water incursion preceded by sailing, particularly hard on port tack?
No, just in my marina slip. Went from clean oil to milk in my slip.
Question 2: Is the anti-siphon fitted with a valve at the top or is it an open loop with a hose attached (no valve)?
Yes, it’s a new one from west marine with the knob at the top of the loop, a “Marelon® Vented Loop, #903003”
Question 3: Do you have the exhaust check valve high in the port cockpit sail locker? No sir, I do not.

[ndutton]

Hmmm, most perplexing. What's bothering me is although water evidence is reported in #4 cylinder (typical in a manifold or exhaust system water incursion) there is no report of stuck exhaust valves.

If it were me, the next area I'd want to eliminate as a problem is the the hot section (the metal piping attached to the exhaust manifold flange) and the short hose that connects it to the Vetus waterlift. I'd disconnect and remove it for physical inspection. Even if no internal obstruction is found I'd replace it with new because in my mind it's the same work as putting the old one back on. If the old hot section is clear, the Vetus waterlift is next.

In a similar case as yours I may be posting the results of an interesting and as far as I know, a never-been-done-before test in a couple of weeks (the soonest I can get to it).