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MD11C Loud Banging or popping noise

riburton

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"I have a MD11C in my Pearson

"I have a MD11C in my Pearson 323 and it has run like a top for the 8 years I have had it. Over the years, without really knowing a lot about diesels I have managed to replace the manifold, the water pump, the wet exhause tank, belts, alternator, thermostat but have never got into the internal parts like the injectors valves,etc. Last night I was running the engine to charge the batterys at a low rpm and sounded good, ran for about 20 minutes then a it started a loud banging or popping noise, that shook the boat. I shut it down and tried to start it again and got the same sound, then shut it down again. A friend said it might be a spring broke on the injector that sets the timing of the firing. To me it sounds more critical than that. I would appreciate any advice on where to start looking. Diesel mechanics seem hard to come by down here, so I suppose I will have to try to figure this out on my own for now."
 
"A hanging injector might soun

"A hanging injector might sound like a loose hammer inside the engine. The cause might be different, but normally lack of fuel/water in fuel. Pull them out and send them to a Bosh shop for service/check. in worst case new elements are needed, but not a major cost. Before re-installing, check out the fuel tank for black sludge at the bottom, filters etc. Use a oil-change pump or similar, open inspection cover or remove sending unit, attach a copper pipe to the pump and pump a couple of liters/quarts into a clear plastic container. Be sure the copper pipe goes to the lowest part of the tank. Change/check all filters and water separators, and do not forget the screen on top of the fuel pump."
 
Remove valve covers and check

Remove valve covers and check for broken valve spring or broken push rod. 11C's have been known to do this.
 
First up MD11C injectors are n

First up MD11C injectors are not timed. They are fuel pulse fed from the injector pump.
You didn't say if the engine was missing. Be pretty obvious on an MD11C. If so like the last post I'd take the valve covers off and make sure all was well. If it looked OK I'd open the compression releases and turn the engine over with the hand crank and listen. If I didn't hear anything I'd start it one cylinder at a time. If it does tun out to be an injector you'll know which one in short order.
To answer you last question yes you can replace valve springs and push rods with the engine in the boat.
Terry
 
No it was not missing at all b

No it was not missing at all before this happened. I will pull the covers today and inspect to see if anything looks wrong. I really appreciate all the help here. Thanks.
 
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