Run off

I have a pair of Perkins 4-154 engines. I started them both up from the flybridge today. Had them both running for about 30 mins at 1200 rpm. Suddenly the port engine opned right up by itself. Wouldn't turn off from key or kill. button. Huge ammounts of thick white smoke from port exhaust. I ran down below and opened the engine hatch but before I could do anything, the engine shut off. I would say that it ran wide open for about 5 mins. Havn't touched it since.I'm asking for any advice on what might have caused it and what I should do next. Thank you

That’s called a runaway. You stop it by smothering the air intake with what ever you can find. Call a Perkins mechanic he will know what needs to be done. Hopefully it stopped from the fuel being shut off and not from catastrophic failure.

I didnt have time to turn off the fuel. After heavy smoking it just stopped by itself. After running very fast for for about four minutes. Do you think it will be OK to turn it over tomorrow and see if it will run?

Thing is, even if it runs and everything looks and sounds fine, will you then trust it unless it is checked out by a mechanic?

If not, go straight to the mechanic.

Joew2604 said:

I didnt have time to turn off the fuel. After heavy smoking it just stopped by itself. After running very fast for for about four minutes. Do you think it will be OK to turn it over tomorrow and see if it will run?

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Don't restart it until you have identified why it ran away. Typically oil or fuel leaking into intake path somehow. And when you do restart, be ready with something solid and flat to put over the intake to choke it off and stop it if ti takes off again. Be sure it's solid and can't get sucked into the intake.

Try turning it over by hand. If locked, you have a major issue.

twistedtree said:

Don't restart it until you have identified why it ran away. Typically oil or fuel leaking into intake path somehow. And when you do restart, be ready with something solid and flat to put over the intake to choke it off and stop it if ti takes off again. Be sure it's solid and can't get sucked into the intake.

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The only thing I would add to this is call the mechanic, don’t monkey around with a runaway unless you know what you are doing. It’s more likely to repeat than to self fix. Not only do you need to find the cause but you need to find out why it stopped.

Lucky after rumaway with Perkins 4-154

After the runaway I didnt know what to expect. After it stopped by itself I didnt know if it was seized or had burnt out the bearings etc. I left it for a day, then pulled the injectors and WAS ABLE TO TURN THE ENGINE WITH A WRENCH ON THE FLYWHEEL. SO IT WASNT SEIZED!! Put the injectors back and took off the air filter. Had a friend on the key and I was down on the engine and ready with a thick book to block off the air in the event it went into runaway again. Hit the starter and on second attempt it started running. Started and stopped it a few time for the next few days. A week later it runs fine and idles fine. I guess I was lucky. It was a scary feeling to have that runaway. And now I'm wondering will it happen again and WHY it happened in the first place, and could it happen again ? I guess only time will tell. Any opinions??

Too much oil in crankcase can cause this.

Runaway

There was not too much oil in the crankcase so dont know why it ran away. Starts and runs fine now. Could have been a major expense. Lucky.

Somehow excess oil, fuel, or combustible fumes found their way into your intake. I'd keep looking to see what caused it. You do not want that to happen again. Look up runaway diesels. Could be a bad thing if it happens again. Diesels are not like a gas engine where you can just cut away the ignition. A mechanical diesel motor will keep running till the fuel source is gone since they fire on compression and fuel.

Check for some oil residue in your intake double check your injectors. Fuel pump starting to go maybe. Seriously have a mechanic find out why a good mechanic if you do not know or have the tools to check out what happened. Not worth losing a motor over even if it is not doing it now.

Engines don't fix themselves. What ever the cause it's still lurking. With that in mind, keep that book close by. For now you need to have a runaway plan.

We actually suggested that you consult a mechanic. That didn't seem to resonate with you so have fun with the book.

Joew2604 said:

And now I'm wondering will it happen again and WHY it happened in the first place, and could it happen again ? I guess only time will tell. Any opinions??

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Same as I posted above. You will never trust that engine completely until you get a mechanic on it.

So why wait?

Get the $25 boat diesel.com membership on line and post your question there. Guessing someone there would have knowledge of that engine and what the path was for the fuel source for that runaway.

have you rechecked your oil level since running the engine? could be fuel leaking into it.

Really, this problem will likely re-occur; as was said above, the engine cannot heal itself.

The engine was getting more fuel than it was supposed to. Possible causes include a failing governor, a pinhole in the lift pump diaphragm, a bad/stuck injector, problem with the fuel return line, crankcase breather or oil filter problem, worn or cracked rings, rear main seal leak, etc. Of course, in turbocharged engines it's not uncommon for the turbo oil circuit to be the culprit.

Joew, please listen to all the good folks here. If this engine runs away again at any fluke moment, someone could be seriously injured or killed or damage could be done to either your boat or someone else's. There is no way I would use that boat until it was determined what caused this to happen.

LaBomba said:

Joew, please listen to all the good folks here. If this engine runs away again at any fluke moment, someone could be seriously injured or killed or damage could be done to either your boat or someone else's. There is no way I would use that boat until it was determined what caused this to happen.

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Which does raise a liability question if injury or death does occur now that you know of the potential issue.

Perhaps the rack on the fuel pump was stuck? Then it freed itself? Check for any contamination in the fuel filters and look at the levers on the pump. YOu might want to get a mechanic to remove the covers to see the rack if they are inline pumps.