Could my Hardware Store Drain Plug lead to Water in the Crank Case?

[WBubble]

1996 Maxum 1900SR.
4.3 liter Mercruiser 2bbl with Vortec heads.

----Here's the crux, up front: Could a blocked line from the water pump to the exhaust riser result in water in the crank case?----

Dewinterized her last month, ran her for about 5 minutes (ran great) then found water in the crank case. It was full.

I'm confident that I have a blown head gasket or block, but I have a nagging doubt I want to eliminate before I pull the motor for disassembly...

When I winterized her last year, one of the plastic threaded plugs that drains the exhaust risers at the L-shaped fitting that runs to the water pump broke off. I fished the piece out and reminded myself to order a new one before summer...Then forgot.

Fast forward to last month when I remembered the plug. I went to the hardware store for a temporary (or permanent) solution so I could run the boat, and ended up buying the shortest stainless steel bolt I could find with matching threads. It was about twice as long as the old blue plastic plug. I put her in and kept dewinterizing.

Here's my nagging question. If my SS bolt is long enough to block the passage of water from the water pump to the exhaust riser, could that be the cause of the water in my crank case? Posting a link to an image of a similar riser and fitting.

 

[WBubble]

[No message]

 

[Lou C]

Doubt it. More likely bad intake gaskets, they will put water right in the cam valley. Even a cracked block or blown HG will take a while to fill up a crankcase with water.

 

[Bt Doctur]

or improper winterizing method, care to tell us how you winterized it?

 

[WBubble]

Winterizing: I remove the plugs from the block and the exhaust risers, 4 total. Then I use compressed air to blow out the remaining water, about 30 seconds per hole.

I recognize that that my most likely culprit is the block.

 

[jimmbo]

Did you pull the drain plug on the intake manifold?

 

[WBubble]

Did you pull the drain plug on the intake manifold?

No. Is that the large bolt with the square drive hole?

 

[jimmbo]

On the 4.3, the intake needs to be drained. Remove the intake, you will mostly find cracks in it. You might just be lucky enough not to have cracked the block.

 

[Lou C]

Also when you remove the drain plugs you must poke them with a thin screwdriver or similar because then can get clogged by rust flakes and may not drain. The block and manifolds together hold approx 4 gallons of water. In addition the large hose that connects the thermostat housing and the front circulation pump had to be removed on the bottom end to drain that pump and water from the front of the engine. And yes the vortec engines (8 bolts on the intake instead of 12 like the pre vortec) do require that you drain the intake. On the pre vortec like mine you did not have to do this.

 

[WBubble]

On the 4.3, the intake needs to be drained. Remove the intake, you will mostly find cracks in it. You might just be lucky enough not to have cracked the block.

Well shoot. I’d better drain that crankcase post haste to avoid rust and check the intake. Since I figured I was dealing with a junk block I hadn’t made it a priority.

Thank you all! I’ll report back after I pull the intake.

 

[just a old boat]

sorry for the hijack,and sorry to hear about your engine.but how do I go about draining the manifold?also do you guy bother running antifreeze through anything or just drain water?also I have an automotive block is there still places to drain water from block?thanks just don't need my engine freezing.

 

[WBubble]

sorry for the hijack,and sorry to hear about your engine.but how do I go about draining the manifold?also do you guy bother running antifreeze through anything or just drain water?also I have an automotive block is there still places to drain water from block?thanks just don't need my engine freezing.

I have 2 plugs with square holes in the intake manifold that I learned here this week are drains.

I have a buddy buddy who drains nothing and pours antifreeze into the muffs with the engine running.

There are drain bolts in the block on each size under the heads.

 

[WBubble]

You guys are geniuses. Cracked intake manifold.

I’m going to try some high-temp JB Weld epoxy Paste before I buy a new one.

 

[Grub54891]

You guys are geniuses. Cracked intake manifold.

I’m going to try some high-temp JB Weld epoxy Paste before I buy a new one.

I'd be leery of jb in that place. There is oil in the cast, don't know if it would hold up over time. For testing, it might be OK. I'd still order a new manifold.

 

[WBubble]

Ready for testing after a few more hours cure time.

 

[Lou C]

Just get a new one....or else waste a few more gallons of motor oil getting the water out the next time it leaks! Its a Vortec engine so those intakes are not hard to find.

 

[Lou C]

I have 2 plugs with square holes in the intake manifold that I learned here this week are drains.

I have a buddy buddy who drains nothing and pours antifreeze into the muffs with the engine running.

There are drain bolts in the block on each size under the heads.

DO NOT use his method, unless the block is drained FIRST. Or else you will wind up with a cracked block, heads and intake sooner or later. If you want to use AF then drain manually poke the holes and back fill with AF. I use either -100 marine AF or mix up a batch of 50/50 Sierra PG no tox AF. Easy, fool proof never a cracked anything is 17 years of doing it.

 

[just a old boat]

that's how iam going to do it empty everything then put antifreeze in just piece of mind!!don't think my intake has drains its a street avenger intake with vortec heads.also you guys just leave outdrives on for winter?bag them up?i have run old car run boats with outboards but this first time with a boat and I/o.and not the original engine so its gonna be a mix bag of learing curves lol.