Seized engine

[Bill6953]

My Mercruiser 5.0 had trouble starting. Eventually when I turned the key all I heard was "clunk". Mistakenly thought the issue was related to fuel pump or oil pressure/fuel shutoff sensor. So I wasted a couple of weeks replacing those parts with no improvement. When I finally checked the oil I found water in the crankcase and in 2 of the cylinders. Unable to turn the flywheel so I tried adding different types of penetrating oils that I read about online. I broke 2 breaker bars trying to get it to move in either direction. I don't understand how it got this bad in just a fee weeks. There are stories online about guys using this method to free up engines that were out in the elements for decades. Am I missing something?

 

[Bt Doctur]

Remove the outdrive and make,beg,borrow a T bar from pipe and a used input shaft welded up. Remove the heads to determine the damage.
spray a -penetrating oil in the cylinders .
Heat the tops of the pistons with a torch `use penetrating so;vent.
add a length of pipe to the T for leverage and try to get the motor to start turning
a motor has 24 hrs from getting wet in salt water, longer in brackish and fresh
Longer than that and its junk

 

[racerone]

Remove the engine.----Take it apart.-----Inspect repair as needed.----Find / repair the water leak.

 

[alldodge]

^^^Agree

 

[Grub54891]

Where are you from? Up north here we have had freezing temperatures.

 

[Bondo]

My Mercruiser 5.0 had trouble starting. Eventually when I turned the key all I heard was "clunk". Mistakenly thought the issue was related to fuel pump or oil pressure/fuel shutoff sensor. So I wasted a couple of weeks replacing those parts with no improvement. When I finally checked the oil I found water in the crankcase and in 2 of the cylinders. Unable to turn the flywheel so I tried adding different types of penetrating oils that I read about online. I broke 2 breaker bars trying to get it to move in either direction. I don't understand how it got this bad in just a fee weeks. There are stories online about guys using this method to free up engines that were out in the elements for decades. Am I missing something?

Ayuh,...... Welcome Aboard,...... Saltwater, or freshwater,..??

 

[Jeff J]

It could have been hydro-locked which can lead to all kinds of fun things if it was actually ran that way. I had a friend 40 years ago think it would be fun to splash his truck through a puddle. Water made into the intake and trashed the engine. Bent connecting rods and the like. However, just residual water in a cylinder would greatly accelerate the rate of corrosion as compared to an engine just left out in the elements.

 

[Scott Danforth]

Waiting 2 weeks......plan on rebuilding the motor.
Pull the drive, pull the motor, then pull the motor apart