Bang! went the diesel

[snowleopard]

The symptoms were....

-blue/grey smoke from the exhaust

-metallic clattering, louder on the exhaust side

-a series of loud bangs

-air filter cover blown off

all the time it was clattering it continued to run smoothly (2-cyl engine).

Any ideas what we'll find when we open it up??

 

[essexboy]

Piston broke, thats the engine, not a reflection on the owner !

 

[Tisme]

Dunno, but it'll probably be expensive. /forums/images/graemlins/frown.gif

 

[AIDY]

Ooooooooooops........ /forums/images/graemlins/frown.gif

 

[Porthandbuoy]

Broken rings allowing oil to be sucked up into combustion chamber.

 

[LittleShip]

Valves dropped into cylinder...........Knacked!! /forums/images/graemlins/frown.gif /forums/images/graemlins/frown.gif /forums/images/graemlins/frown.gif

Tom

 

[ipw]

inlet valve seat come out

 

[snowleopard]

Come on guys, give me a break. At least somebody might offer a less expensive possibility.

BTW, it's not the boat, it's next door's tractor (chinese made).

 

[boguing]

Cam chain tension pulley collapsed, so chain rattled, but valve timing became variable. Hence poor combustion and smoke, next, valve to piston clash, backfire finally blowing air back out of the in.

Or any one of another billion permutations.

 

[chuckaduck]

what engine ??

 

[snowleopard]

Not that, it's a pushrod engine.

Additional info - sump overfull, oil not emulsioned so likely to be fuel leaking into the oil. Not sure how that could have happened but it must have affected lubrication.

 

[gfbalduc]

I once had similar symptoms when the spring of one valve was broken: if an input valve doesn't close completely, air escaping back into the inlet manifold can blow out the filter, and loss of compression would cause unburnt diesel seeping into the sump.

Afraid this is not the more likely cause, though, and all others look pretty expensive.....

good luck!

 

[VicS]

If fuel has got into the sump it may be via defective seal on the injection pump, or the "lift" pump if it has one.

 

[Stoaty]

This could be just a poorley performing injector. it has all the symptoms. If you remove them, then loosen a pipe and invert it so when you you screw the injector back in it is pointing upwards you can crank the engine and watch the spray pattern. It should be a uniforn very fine mist, If it's a jet or any dribbling, then it's duff and needs a service. This won't cost you anything to check.

Sometimes a jetting or dribbling injector will cause diesel to be pushed past the rings/valves and it will find its way through crancase venting back to the inlet manifold.

Of course in the process of removing your injectors you would probably find out if any piston/valve damage had occured.

 

[catmandoo]

Ble means burning oil ie oil gets past piston rings into head -carbon build up on valves which jam in guides hitting pistons and fuel combusting in exhaust give s bangs .

So you will see carbon on valves and damaged valves and pistons