Water in oil

I have a 34’ Sport Fisher with twin Crusader 454’s. It is fresh water cooled. We were out this weekend Silver (Coho Salmon) fishing (great fishing) and everything worked just fine trolling. We stopped and anchored for a while and then when we headed in the starboard engine started running rough. By the time we got to Valdez harbor (about 15 min) it would not idle and died. Made for rough parking since the wind had really picked up. After we got settled in we started trying to figure out the problem and ended up finding the oil level was way high and milky looking. Great, we have water in the oil. Checked the antifreeze and it was still full so we figured it must be salt water getting in. From what I could tell from the manual, the oil cooler seemed like the culprit in this case. We bypassed the cooler and have changed out the oil 3 times and although each time the oil looks better it still is milky looking and we are still gaining a couple of quarts. So unless we have discovered a new source of oil we still have a problem. Does oil and saltwater foam and expand when mixed? Since it’s fresh water cooled is there another place the water can get into the oil. How a bought the risers, can oil get in that way?
I appreciate any help out there, George

The oil cooler is the only "reasonable" way raw water can enter the crankcase. How did you bypass the cooler? There is no oil path from exh. manifolds out. I would test the U cooler and make sure it leaks.

HOw much of an increase are you talking about after two oil changes? And, how much runtime accumulates to create that quantity?

Is there a water heater connected to this motor? I don't understand how you can not be loosing coolant.

The oil pressure inside the oil cooler is much higher than the raw water pressure so that leak path is very unlikely.

3 qts in 5-10 minutes is a huge 'leak'. If you are positive it is water (not antifreeze), I'd pull the spark plugs and see if there is any water o rust in the cylinders. if so, I'd suspect the exhaust elbows/risers are gone and your engine is a bit 'worn'.

Pumping 3 quarts of water thru the piston rings in 10 minutes would be quite spectacular! I suppose you do need to verify the combustion chambers/spark plugs are dry.
The deal with the water heater is a possible chance that the HE stays full until the WH to engine hoses drain out. The WH would need to be above the engine (but below the HE filler neck) for this drainback to occur. Overall, it is much easier to explain coolant in the crankcase, than raw water in the crankcase. Particularly when the oil cooler is out of the picture.

I don't think the flow (3 qts) occurs during the 10 minute run time but in the cool-down period that follows.

The thought is there is a tiny void in the raw water side and while the engine is running, exhaust system pressure keeps the leak to a minimum. After shutdown, the void provides an exit path for the raw water into the manifold. water in the manifold finds an exhaust valve open and enters cylinder. Cylinder has significant wear and water seems past rings into crankcase. The theory is this happens overs a few hours not ten minutes. I'd expect a leakdown test to verify a large leakage rate.....

I'd also guess the issue has existed for a while but was only noticed during the high wind - one engine docking manuever. that was the driver for the check the plugs/cylinders for H2O.

THere are some divergent symptoms here, so I really have no idea what is wrong!! But, I would do these things:

1. Check the oil cooler for water to oil leaks
2. Pull all the plugs, look for signs of water, rust, unusual color, etc.
3. Do a cooling system pressure check

Based on the results, that should point you to the issue.

Found the problem. The riser had rusted out and let salt water enter the exhaust manifold and than the engine. The jury is still out on how much damage may have been done So far I've pulled the risers, exhaust, intake manifold, and the heads. I'm replacing all my risers and getting the heads rebult. We'll see after that. Any recommendations on the best place to get the risers? Thanks again for all the helpful input.

LegaSea Alaska said:

The extra volume is there immediately after the engine is shut down. While this may have been developing for a while, the symptoms were not there until the last trip.

Click to expand...

Thanks for the return note. It sounds like you found the smoking gun. It's also interesting how quarts of seawater made it into the crankcase thru the exhaust valves. Presumably, salt water bypassed the piston rings?

What do the bores look like? Any rust damage? If so you are out of luck as the engines will need to go either as cores for new or to a shop for over boring. One problem that is not apparent when inspecting engines that have been run with water in the oil is that the bearing babbit gets worn off rapidly. I had this happen to my old Gold Wing, and it took only a half hour of riding to completely kill the engine; three month old engine needed a total rebuild. Everything may look good but without a teardown you cannot be sure. If it were me, I would pull the engine and at the very least remove the caps off the crankshaft. In for a penny in for a pound. As long as it's out might as well have it to the shop for new rings and bearings....aren't boats fun?

If by best you mean cheapest, I can't help. I would suggest our hosts as I have found them to be competitive and their shipping rates not out of line. The manifolds and risers for your engine are made aftermarket by osco (www.oscomotors.com). You can search their web catalog for their parts numbers and then use the search box on this websit to find the parts in the Marineengine.com online catalog.
If you opt for genuine Crusader be prepared for sticker shock.