I have a 32 ft searay with twin 350 mercruiser close cooling . ;Last run @ 3000 rpm engine overheated and slowly lost power. Shut down and allowed to cool. After 1 hour wouldnt start , hydraulic lock in cylinders .
On tear down , removed plugs and found coolant in cylinders 6,7,8. ie both banks and lowest on the block. Removed intake manifold and found coolant in the pushrod gallery and in the sump pan [ elevated oil level ] heat exchanger empty of coolant but engine is not seized.
On inspection of intake manifold I cannot see any cracks in coolant chamber, but there is a sheet metal cover over the center section riveted in place , that I cannot inspect. Is there an easy way to pressure test the intake manifold before I replace?
Other suspicion is from exhaust manifold but both banks at same time seems unlikely
IF intake manifold gasket leaked , can coolant get onto cylinders?
If exhaust manifold leaked can coolant get to pushrod gallery ?
I cannot make these pieces fit - HELP
On tear down , removed plugs and found coolant in cylinders 6,7,8. ie both banks and lowest on the block. Removed intake manifold and found coolant in the pushrod gallery and in the sump pan [ elevated oil level ] heat exchanger empty of coolant but engine is not seized.
On inspection of intake manifold I cannot see any cracks in coolant chamber, but there is a sheet metal cover over the center section riveted in place , that I cannot inspect. Is there an easy way to pressure test the intake manifold before I replace?
Other suspicion is from exhaust manifold but both banks at same time seems unlikely
IF intake manifold gasket leaked , can coolant get onto cylinders?
If exhaust manifold leaked can coolant get to pushrod gallery ?
I cannot make these pieces fit - HELP
