Water in the Crank Case... Doh!

97_245_sd · **Posted:** Wed Sep 05, 2012 10:32 am

That part is an exhaust flapper, that was supposed to prevent water from backflowing into the engine from outside. There was a service bulletin where they discontinued using them and recommended removing them and filling the holes in the exhaust pipe.
[url]http://www.marinemechanic.com/volvo/volvo/2010/25-2-5A[1]exhaustflapper.pdf[/url]

Not sure if they could fail and cause the engine to fill with water, but I suppose it is possible.

cdig · **Joined:** Mon Sep 03, 2012 9:05 am **Posts:** 72

Ok, so I just talked to the Four Winns dealer here, and he figures that the plastic piece I found in the exhaust port is the exhaust back flow seal. I confirmed this with the part number on the piece. The fact that it is no longer doing it's job of keeping water out of the exhaust manifolds would be a good bet as to why there is water in the cylinders! I'm going to change the oil and plugs tonight and see what happens... This just made my Day!

Paul I. · **Posted:** Wed Sep 05, 2012 10:39 am

LouC wrote:

It could be from it not being winterized which would cause a cracked block. Other causes are a blown headgasket and failed (rusted out) exhaust manifolds/risers.
You can swap the motor with an auto engine but you have to use all the marine accessories like the starter, alternator, fuel system, etc. You also need to add marine head gaskets, core plugs and circulating pump, the auto stuff will not last.

I am am by far an expert on this. It been my understanding that you should not use a car engine in a boat. A truck engine would be more in line with marine. A 350 car engine vs a 350 truck are different in terms of being more beefer due to torque loads.

Here is a link that I found on this, if it helps: http://www.ehow.com/about_6640040_marin ... ngine.html:

cdig · **Joined:** Mon Sep 03, 2012 9:05 am **Posts:** 72

Ok, check that, looks like that part is not necessary, from the bulletin that 97_245_sd provided.

So what's keeping water out of the exhaust manifolds then?

ric · **Posted:** Wed Sep 05, 2012 10:49 am

cdig wrote:

Ok, check that, looks like that part is not necessary, from the bulletin that 97_245_sd provided.

So what's keeping water out of the exhaust manifolds then?

gravity (the gooseneck).

I imagine if you had some HUGE swells hitting the stern of the boat it could be possible for water to backwash in. But they'd also be going over the boat.

rpengr · **Posted:** Wed Sep 05, 2012 11:02 am

cdig wrote:

Ok, check that, looks like that part is not necessary, from the bulletin that 97_245_sd provided.

So what's keeping water out of the exhaust manifolds then?

Water is normally kept out of the engine because the "riser" is above the water level. Also, with the engine running, exhaust pressure forces exhaust & water out through the outdrive. Without the riser, water comes in the the exhaust Y-pipe only as high as the water level outside the boat.

The flapper was there to prevent water from sloshing higher up the pipe from rough seas and/or large wake when the engine is not running. With the engine off, if a wave sloshed high enough, water could possibly slosh high enough in the exhaust system to get up to the top of the riser, and therefore back down into the engine.

Apparently, the flapper did more harm than good, therefore Volvo called for it's removal. If there was any restriction in the exhaust cooling water, the flapper would partially melt, then come loose and lodge somewhere lower down. I ran my 1987 OMC for many years without the flapper without a problem.

I sounds like your flapper may have obstructed the exhaust/water exit enough that water built up, and probably went back into the engine when it was shut off. However, this explains a little water in the cylinders, but not a large quantity in the crank...so it still might be the cracked block or bad head gasket issues mentioned earlier.

Regarding doing a compression check: If you check with any water in the cylinders, you will break another gage. I would try to get the engine to run first. Do all the cleaning you can with WD-40 and cranking with the spark plugs out. Then attempt to start (may need a can of "starting fluid" (ether)). If you can get it to run for at least a couple minutes, then do the compression check to see what condition you have.

cdig · **Joined:** Mon Sep 03, 2012 9:05 am **Posts:** 72

I wasn't aware that moisture would affect the compression tester... oops. I picked up another one today, and I'll follow your advise on getting the engine cleaned out and running first.

Just to be sure, since I've got the stern drive unit off already, I should just be able to put an extension on the water intake hose and put it in a barrel of water placed under the exhaust port right? this would allow the water to circulate? Is the exhaust water going to come shooting out when I start the engine? Or is there any other fluids that I need to cap off?

rpengr · **Posted:** Wed Sep 05, 2012 1:40 pm

cdig wrote:

I wasn't aware that moisture would affect the compression tester... oops. I picked up another one today, and I'll follow your advise on getting the engine cleaned out and running first.

Just to be sure, since I've got the stern drive unit off already, I should just be able to put an extension on the water intake hose and put it in a barrel of water placed under the exhaust port right? this would allow the water to circulate? Is the exhaust water going to come shooting out when I start the engine? Or is there any other fluids that I need to cap off?

Wherever the exhaust comes out...water will be spraying out also. You don't need to recirculate it. Let it dump on the ground. If your exhaust hoses and Y-pipe are not hooked up, then it will be spraying inside the boat.

Did you remove the upper & lower unit, but the transom bracket is still on? If so, you can try to rig a garden hose to the water inlet hose. Try to protect the gimble bearing from getting wet. If you do draw from a barrel, make sure it is elevated almost as high as the engine.

fiznuka · **Posted:** Wed Sep 05, 2012 2:30 pm

Sounds more like someone forgot to put the bilge plug in and sunk the boat at the ramp.

cdig · **Joined:** Mon Sep 03, 2012 9:05 am **Posts:** 72

rpengr - "Did you remove the upper & lower unit, but the transom bracket is still on? If so, you can try to rig a garden hose to the water inlet hose."

- Yes, that's the point I'm at. I was kind of thinking the same thing, just attaching a garden hose somehow.

fiznuka - that is my ultimate hope and prayer... The boat has alot of leaves and debris in it, and as it turns out the bilge plug is missing... could it be that this thing was just left tied up at the dock, got a crap load of water washed over the back of it, and it sank the back end down enough to flood the engine? My nights will be spent in the garage until I figure this thing out.

LouC · **Posted:** Wed Sep 05, 2012 3:57 pm

Well you never know and you have nothing to lose by trying. I don't know if a Volvo impeller would suck water up the way you were thinking of doing it, I'd want to rig up a fitting (pvc) to the water intake hose in the pivot housing and clamp that to a garden house, that puts pressure to it and the impeller won't be starved for water.

NiagaraChillin · **Posted:** Wed Sep 05, 2012 5:27 pm

You should capture this engine startup on video, would be interesting to see how it does after all you have told us so far...

cdig · **Joined:** Mon Sep 03, 2012 9:05 am **Posts:** 72

Video eh? That's a great idea!

Tonight I pulled all the plugs and sprayed liberally with wd40. Also pulled the exh bellows and removed the remnants of the backflow valves. Also pulled the dipstick tube and let the 'fluid' drain from the engine into the bilge. Ever try draining whip cream through a straw? That's what it's like coming out o the oil pan...

One question tonight... Is there a 'low oil cutoff' sensor somewhere? I've been charging the battery and it's got lots of juice but when I try to crank it over I get nothing since I drained the oil. ???

That and a 6 pack of beer is all I got done tonigt, hopefully it's all drained out by tomorrow eve so I can go at it with some fresh oil and plugs and try to start it!

LouC · **Posted:** Thu Sep 06, 2012 5:45 am

You have to get a good vaccum pump to change the oil, no need to make that big mess in the bilge, and if you get oil all over you need to clean it well. Reason being, if you don't and your bilge pump kicks on, you can get a fine (at least here for sure) for putting oil in the water. Let us know what happens with the engine....

rpengr · **Posted:** Thu Sep 06, 2012 7:59 am

cdig wrote:

One question tonight... Is there a 'low oil cutoff' sensor somewhere? I've been charging the battery and it's got lots of juice but when I try to crank it over I get nothing since I drained the oil. ???

No low oil cutoff sensor that I am aware of, but I could be wrong.

Try to rotate that engine everyday so it doesn't seize up, even if it is with a wrench on the front of the crankshaft.

www.iFourWinns.com

Water in the Crank Case... Doh!

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