Engine Troubleshooting - Help please

Greetings! I recently purchased a 24' FiberForm Cabin Cruiser. I bought it knowing it had engine problems. The boat has a Ford 351 and was told by the previous owner that he found anti-freeze in the oil.

To all you mechanics what is the first step in solving the problem? Many people have told me to first pull off the heads. I have also been advised that the problem might be cracked exhaust manifolds.

Any advise or insight is welcome!

 

If it was anti-freeze, it must have a closed cooling system - so the exhaust manifolds are off the hook. My initial guess would be head gaskets - but I'd check the compression before I tore off the heads. Who knows; It could be getting in from behind the timing cover.

 

I do know the boat has "Fresh Water Cooling" added to the engine. Does this mean it is a closed cooling system? Any other advice is welcome!

 

Considering the nature of your questions, two natural replies come to bear. Purchase a repair manual for your drive and engine combo (OMC?) and secondly, you'd likely be best advised to have a marine mechanic look her over, as you're a little over your head at the moment. A manual can help bring you closer to understanding what's going on, but a good mechanic can diagnose your ills, likely pretty quickly. A well placed 100 dollar bill can gain you information and assessment of your project, possibly tips to repairs and a place to get parts too.

 

With regards to my question. I am posting this to get insight and advice on what people think might be the issue. I realize I am not a mechanic and don't plan on doing the work myself. I do plan to educate myself which is why I posted my question.

Any insight and or suggestions is welcome!

 

My thoughts are can you trust the diagnosis of the last owner.
I would change the oil and run it again. No need to run antifreeze for the check as long as you don't forget to drain it again after the diagnosis is complete.

However a head gasket is top of the list.