500 Caddy milky oil?

[Lll122]

I recently acquired a project airboat with a 500 Caddy dd. I have a lot of work to do to it including installing new poly on the bottom, but I’d like to get the engine going first before I sink too much money into it . The boat has been sitting a while, the engine starts and runs, but the engine oil is milky. I drained oil and refilled, but I’m assuming it has a coolant leak somewhere. Any suggestions for a likely cause of the water intrusion, or what I should check first? Are there common issues with these motors that could cause this? I plan on doing a leak down test on the cylinders, and pulling the intake and changing gaskets….

The engine does not smoke and I don’t notice any bubbling in the coolant…


Any help or tips would be appreciated!

 

[John Fenner]

Could be the timing cover gasket or cover itself leaking into crankcase.

 

[SWAMPHUNTER45]

First question is how milky and have you flushed it and changed the oil ?

There can be 5-10 actual issues that cause it but if the boat has been sitting it can be as simple as a cold runner and humidity.

Flush it with a little diesel and start fresh

 

[pontoon outlaw]

I recently acquired a project airboat with a 500 Caddy dd. I have a lot of work to do to it including installing new poly on the bottom, but I’d like to get the engine going first before I sink too much money into it . The boat has been sitting a while, the engine starts and runs, but the engine oil is milky. I drained oil and refilled, but I’m assuming it has a coolant leak somewhere. Any suggestions for a likely cause of the water intrusion, or what I should check first? Are there common issues with these motors that could cause this? I plan on doing a leak down test on the cylinders, and pulling the intake and changing gaskets….

The engine does not smoke and I don’t notice any bubbling in the coolant…


Any help or tips would be appreciated!

I had one like that and we just drained the oil and struck out.. was the carb covered ?