I have a 1985 33' Egg Harbor with same year 454 Crusaders (model 350) FWC. About 800 hours on them. We were out on the water yesterday and running for several hours and the engines were running fine. After going through a "no wake zone" I powered them up and the port engine just died. I was able to restart it but it ran extremely rough and white smoke (not steam) was coming out of the exhaust. Limped back to the dock on one engine.

Checked coolant level at heat exchanger and could see none. Pulled oil dipstick and found a large amount of a coolant/oil mix. Also noticed some oil dripping out of the exhaust.

Any thoughts on the cause and where to start diagnostics would be appreciated

Oh OK, well glad your getting it back in the water soon, still good cruising weather left to the season! Enjoy!

Update on Engine Failure: Insurance will not pay since they said that it was a mechanical failure. The risk pin seized. Really don't know why it happened, but we opted for a remanufactured 454 with a total cost with labor at about 13k. The new engine was twice the price and the warranty was only one year longer. She should be back in the water later this week.

How did it go??

Bad news...diagnosis is catastrophic engine failure. Piston blown into pieces, while rod ran a hole in the block. At this point, no known cause. No symptoms prior to the incident. Reported to insurance company and there is slight chance of coverage. Only solution is remanufactured or new engine. Will keep you posted.