omc 4.3l - water in cylinders after running

[mlstanhope]

have a 1988 4.3l omc w/cobra drive. engine runs beautifully under load until shutting off and sitting a bit. at that point, starter really labors to turn engine over. pulled plugs and getting some water. no initial indications of water in the oil pan. impeller in water pump was replaced recently after engine ran somewhat hotter than normal. am investigating possible blown head gaskets or cracked block. want to know if on right track, or if there may be other possibilities to look at. thanks for any advice.

 

[DJ]

Re: omc 4.3l - water in cylinders after running

falefel,<br /><br />Do not overlook the manifolds and risers-exhaust.

 

[DaveM]

Re: omc 4.3l - water in cylinders after running

You might want to find out when the water is getting in. If it runs good under load, then maybe water is getting pulled in when either you shut the motor off or you try restarting. Is the idle set correctly? Does it diesel when shut off?<br /><br />I had the same problem with my 4.3L Volvo until I corrected the idle. The GM 4.3L motors have a tendency to spin backwards when starting hard or when shutting off at a high idle speed. Look for the flywheel to do about a 1/2 turn backwards just before the motor comes to a complete stop.

 

[Boatist]

Re: omc 4.3l - water in cylinders after running

I would check the manifold real good. If you do any saltwater and you have not replaced the manifold I will bet that the problem. When they start to go bad motor can also overheat at speed but usually ok at low RPMS. When they go bad the rust and scale can plug up the holes where the water exits and restrick the water flow so it get hot. Also water seeps from water passage into exhaust passage and back into the engine. Good luck and let us know.