89 Cheetah 4.3L Mercruiser Oil/Water Mix

[Mattb22006]

Looking for some advice on what to check with a 4.3L mercruiser thats mixing oil and water. It is mixing pretty bad, the oil water mix is all the way inside the valve covers. Just looking where to look first. Going to start tearing the engine down to diagnose the issue. Also looking for some advice if its even worth the time. Order should I just replace the motor.

Main thing is with this engine, most of the major upgrades have been done to it. Larger cooling tube, added alternator, coil pack upgrade. So I dont want to just toss it yet.

 

[tpenfield]

Cracked engine block, blown head gasket, or possibly exhaust manifold gasket leak. Based on your description, I'd be voting for the cracked block.

 

[Scott Danforth]

look at who winterized it last.

 

[Mattb22006]

Any recommendations on a replacement?

 

[Rick Stephens]

Before you tear it down, pressure test the block with the exhaust manifold water lines blocked off. Make sure your cracks are in the block before assuming so.