Engine Melted

[rgaidies]

I have a major issue!

Purchased a 1982 26' carver with a 260 mercruiser engine.
The engine block was replaced 2 years ago, apparently a cracked block.
Previous owner claimed he drove the boat for 8 hours after the block was replaced with no issue.

My first lauch this occurred.

Boat launched outdrive lowered.
Engine started (quite easily)
I revved to about 2000 rpm
within approximately 5 minutes I smelt an odor
Opened the engine cover and nearly shit!
Looked like smoke coming out of the air breather.

I left it idle removed air breather and steam was coming out of
both hoses which go from rocker cover to carb. Much steam.

The starboard exhaust port melted the elbow and popped two of the 4
S.S strap clamps. The exhaust elbow severely deformed.

On the same side (Starboard) a milky substance (oil & water) was coming
out somewhere underneath the exhaust manifold.

The boat ran for about 8 minutes and when I shut it off it made some very
rude sounds while cooling. The sound of metal contracting from being heated.

I checked the dip stick and water was evident in the oil.

Any ideas as to what may have happened? Impeller not functioning/ thermostat shut closed/ blown headgasket?

I am looking for adivice on what to look for and where to start on repair.

The boat sat in outside storage for approximately 2 years.
I did test run with outdrive muffs on but really only to ensure it turned over and started, maybe 5-6 seconds.

Thanks for any advice you may have.

 

[Chris]

Welcome to the board rgaidies, nice to have you here.

Sorry to hear about your trouble, that sucks.

I would imagine the cause could be related to any of the things you mentioned. It obviously sounds like you overheated, what came first though is another question.

Did you encounter any warning horns, buzzers etc. after it started up?

-Chris

 

[rgaidies]

no audible warnings just the steam and a high reading on temp gage

 

[Chris]

The high temp reading came early on? If it did, most likely it overheated first and things went south from there.

The overheat could have been caused by something simple like a worn impellar, or from something like a blockage somewhere in the cooling system.

The audible horn might not working and that's why it might not have sounded.

 

[Chris E]

more than likely a worn impeller - water pressure from a hose is enough to circulate through the engine (about 60psi). as soon as it hits the water, then it has to work on it's own - that's when the fun begins. fix the impeller and then do a compression test and leakdown test on the engine to see what - if any damage has been done. more than likely you will have to replace all the rubber hoses on the engine.

a word of advice - (unfortunatley it's a little late), always sit with the engine on the 1st start up and check the hoses for heat and the manifolds for temperature. if it starts to get hot (they get warm - not hot) to the touch you have a problem, shut down before it's too late.

 

[daren34]

if you have water in the oil then you have at least a blown head gasket
if not other major damage to the engine
sounds like there was no water from the pump at the lake
the water hose can mask potential probs
in my opinion the heads will have to come off and the lower unit to check the water pump
daren