Well, this looks like a disaster...

[Vettedrmr]

<Sigh> Worked on getting our new (to us) '08 22ve ready for going to the lake, and proceeded to change the oil as a part of the dewinterization process. Quick background: we bought this boat last September, and as a part of that process checked the engine oil, which appeared to be clean. Engine was replaced in the spring of '23, and has 5 hours or less run time since then.

Item 1: the oil is thick, like REALLY thick. I have the paperwork from the engine replacement, and it shows the oil used was "25w-40 marine". It almost feels like gear oil.

But *this* is Item 2:

Engine Oil Resized.jpg

Ok, so there's 3 different reasons in my experience that this can happen:

1. Blown head gasket
2. Cracked cylinder head
3. Cracked engine block

Another could be some kind of engine oil/water heat exchanger. Do these boats have anything like this, or something else that could introduce water to the oil?

Thanks in advance, and have a good one,
Mike

[h2o-ski]

They do not have an engine oil cooler (assuming its a 5.7L as not sure on the 6.0L). I use 15w-40 in my engine because of the abuse it gets as a marine engine.

You are correct in those although there might be a 4th, the exhaust could have a crack internally. A small enough crack can cause oil to weep though the exhaust valve and into the crankcase but not enough for a hydrolock situation.

Why was the engine originally replaced?

[lee]

What engine do you have? Most do not have an engine oil cooler, just one for the transmission fluid.

[boatwakes]

Check the middle spark plugs on both sides for water or rust. Water reversion through the exhaust or leaking flange gasket between the mixing elbow and manifold will allow water to be ingested as well.

[AussieJohn]

I can’t wait to hear what was the problem
Over here in Victoria Australia we are nearly at the end of our skiing season
Hopefully over Easter I can get the boat out a few times


Sent from my iPhone using Tapatalk

[Vettedrmr]

Sorry for not getting back sooner, been doing more digging and trying to get as much of this goo out of the engine as possible. It took 3 DAYS for this stuff to gravity drain out of the remote hose. I think there may be an obstruction somewhere in the drain line, but since you have to lift the engine to get to the pan fitting, that's not happening.

I pulled all 8 spark plugs, none look steam cleaned, although there are what could be interpreted as water spots, or just simple humidity, on two of the plugs. I pulled the knock sensors to drain the water out of the block, everything that came out was clean, red, coolant.

My brother has a borescope, we took a look at the top of the pistons and valves. All the pistons and valves look normal. We pulled the valve covers, and the cover and the top of the valve train has goo all over it, that's going to be cleaned up pronto. Since the oil filter is off, and the plugs are out, we spun the engine over with clean, but slightly used, engine oil (10 minutes in another engine after a rebuild) in the pan. After pumping about 15 seconds, the oil stopped showing signs of goo.

2025-04-19_14-11-05.jpg
Next step is manually cleaning the top of the valve train, putting on an oil filter, then cranking the engine over until we get oiling of the rocker arms.

They do not have an engine oil cooler (assuming its a 5.7L as not sure on the 6.0L). I use 15w-40 in my engine because of the abuse it gets as a marine engine.

.
.
Why was the engine originally replaced?

Y'all are correct, no engine oil cooler. That was more of a hope, since boat engines typically run cool (at least in my experience). The original engine was replaced because the previous owners assumed they didn't need to winterize the engine down in N. Dallas. Oops.

Check the middle spark plugs on both sides for water or rust. Water reversion through the exhaust or leaking flange gasket between the mixing elbow and manifold will allow water to be ingested as well.

You have given me the first good reason that this might have happened in the first place. I used a fake-a-lake as part of the winterizing process, and that might have overfilled the exhaust prior to starting the engine. I do have one question: what do you mean by "reversion"?

Thanks so much for all the comments, and have a good one,
Mike

[Vettedrmr]

UPDATE: I spent the afternoon pressurizing the engine with the clean, used oil. Pulled the valve covers and cleaned them and the top of the heads with rags and WD-40. Then I spun the engine over 30 seconds at a time and watched to see if I was getting oil up into the pushrods. Watch for oil or goo to start showing up. Wait 5 minutes for the starter to cool. Repeat as necessary.

I lost count of how many times I did this, but eventually I got most of the goo flushed out and clean oil coming up over all 16 pushrods & rocker arms. I then did a compression test, and all 8 cylinders came back with readings from 190-200, nicely grouped together.

This just adds to the list of tests that tell me the engine is OK. Next up is pulling the exhaust manifolds and checking them for leaks (thanks boatwakes ).

Y'all have a good one,
Mike

[h2o-ski]

Reversion is when water is sucked into the exhaust from the camshaft overlap. Marine camshafts are designed to minimize the amount of reversion for obvious reasons.