2002 Mercruiser 3.0 - No Oil? Engine Swap?

Hatch19 said:

Hey guys - Two part question..

#1 - I recently acquired a 2002 Bayline with a 3.0 Merc that hasn't ran in 2 years. It does have a crack on the port side of the block (unknown if overheated or not winterized). I Drained the oil out of it and did get some water but it was not milky looking. Put 5 Qts of oil into the fill and nothing shows on the dip stick and there are not visible external leaks anywhere (I have not attempted to run it) I'm at a loss.... any suggestions?

#2 - I'm looking at just swapping the motor out with a known running one. Will a 1997 Merc 3.0 be a direct drop in fit? Only difference I can see in my motor and the new motor is where the shift cables mount up (starboard side vs on top of the rocker cover)

Any input is appreciated!

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Scott06 said:

#1 - block wouldnt crack like that from over heat only from not winterizing - also need to check if manifold is cracked as well.

it is worth starting it on the hose and seeing if you get water into the oil . Sometimes will just crack externally and people slap JB weld on it and call it good.

1997 will be a drop in. Especially if you have two engines worth of acessories etc.

In all likely hood the block is toast, would look the boat over drive as likely it had no maintenance. Fuel may be contaminated as well.

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Hatch19 said:

Scott - Thanks, the "new to me" motor is a complete set up so I'm leaning towards just a swap... time troubleshooting issue motor vs swapping a working one.

it is worth starting it on the hose and seeing if you get water into the oil . Sometimes will just crack externally and people slap JB weld on it and call it good. I have read that and that was my initial plan but... after adding oil I still have none in the pan.. confirmed by attempting to drain the oil again... I'm hesitant to run a motor that I cannot verify it has oil.

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Scott06 said:

Was thinking the dipstick was broken or wrong one ... You put 5 qts in the engine (its a 4 qt motor) and there is nothing in the pan? You pulled the oil pan drain plug and there is no oil? Not sure where it would go unless it leaked out somewhere ??

Cant conceive a situation where the head wad cracked such that it filled the cylinders or block was so cracked it filled the cooling jacket- dont think on the lifter side there is a jacket behind the lifters/pushrods.

if the cost of the other engine doesnt bother you and it is actually a good engine (compression and oil pressure) may be a better bet

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Hatch19 said:

I had the same thought about the dipstick so I straightened out a coat hanger and pushed it all the way in, still nada.

Compression on the replacement motor is ~170psi.

The motor is already out of the boat, is there a simple way to check oil pressure?

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