3208 Runaway

[BonBini]

The story goes: Boat was heading out of marina and never made it past the break wall when the port started running strange. Took it out of gear and the rpms started climbing with lots of smoke. Would not shut off. Engine finally quit running and would not restart.

Service Tech found oil all over the engine room. Engine way over full on oil and heavily diluted with fuel. Bent pushrods, pulled one head and found bent valves and damaged pistons. Marina Techs pulled engine, boxed things up and shipped it out.

Inspecting the engine: The intake track and aftercooler loaded with fuel/oil. Eight bent exhaust valves. Eight bent exhaust push tubes. Eight damaged pistons and lower end bearings fatigued. During fuel nozzle testing, I seen one high pressure line leaking just before it blew out at somewhere around 1000 psi. Service records show 17hrs on last oil change.

The one nozzle leaking at its high pressure line surly caused a misfire. The oil pressure was most likely very low too.

I thought some of you motor heads may find this interesting.

http://s811.photobucket.com/albums/zz31/BonBini268/3208Marine/?action=view&current=db5ccc2e.pbw

 

[fc3]

Would such a leak be noticed on a routine visual inspection of the engine or do you have to disassemble?

 

[Pietro]

The one nozzle leaking at its high pressure line surly caused a misfire.

Can this be the cause of that mess??? :smt017

 

[BonBini]

Would such a leak be noticed on a routine visual inspection of the engine or do you have to disassemble?

With the nozzle in the head, there was no way for it to blow apart, just leak some every time fuel got pumped to it. So a visual inspection would have looked fine. At low idle, only a drop or two is sprayed per cylinder. So the leaking line most likely never let the nozzle reach its 1800 psi to pop a spray. The dead cylinder went unnoticed for some time. Throttled up the nozzle may have sprayed some at a delayed timing!

Can this be the cause of that mess??? :smt017

With enough fuel in the oil to allow the crank to start whipping it up to a foam, the breather can become a fuel source. Don’t know how many rpms it took to float the valves.