Detroit 353 loud knock

[Plankton]

Well finally got some good skidding weather and the engine blew up on the first turn.

Always started instantly, no smoke except regular diesel smoke when she's pulling up a good hill. Doesn't burn oil, doesn't leak oil.

I pulled into the landing unhitched my chokers and when I throttled up to winch them out of the logs it sputtered and started knocking loudly. More like a clack. Shut it off instantly, visually checked outside of the engine nothing leaking oil or any thing out of the ordinary. Oil level is good. Antifreeze is good. Started it up for a second same loud clacking so I shut it off.

Never had an engine do anything like this so entirely out of my element here. What would cause a sound like that? Just all of the sudden? Previous owner used ether alot I think, on really cold mornings I do a small squirt in the intake then crank. But mostly don't use it.

Also if anyone knows of a good detroit mechanic in western mass let me know.

Thanks, Daniel

[lumberjack48]

  Pull the valve cover off, you might have something broke on the rack.

[madmari]

Might have broken a rocker arm, which will make a "clackety" sound and would make it sputter. Not a huge deal if that's it. If it wasn't under a heavy load, it's probably nothing major as long as your oil and coolant are clean. Hope for the best..

[coxy]

it may have broke a valve and its hammering on top of the piston they are good for that

[loggah]

I had the top of a piston break one time right around top ring grove! the engine ran with a loud rapping sound up top,nothing in oil or antifreeze.

[sandsawmill14]

could be an injector too but whatever it is you will have to start with the valve cover and just work your way down and hope you find it before you get to the oil pan ;D  good luck with it maybe it wont be to bad

[jwilly3879]

Could also be the blower. My hard the bolts on the blower drive back out and the blower went out of time. Awful noises.

[Plankton]

Thanks alot for the replies guys. When it happened I had no idea what to do and before I pull anything apart I like to at least know what to look for/where to look for it. I'll pull the valve cover off tommorow and start from there I guess.

Called RCS diesel and they have a completely rebuilt 353 if I bring them my engine they'll give me it for 4800. Almost as much as I paid for my skidder but it comes with a warranty and I know it would work.

I'll try to fix it myself first if I mess it up and get the new one I have nothing to lose!

[sandsawmill14]

unless you missed a rod sticking out of the block or something i wouldnt think it would be that bad

[grassfed]

Take a mechanic's stethoscope if you have one or long pry bar/screwdriver with a plastic handle or even an old wooden ax handle and put one end against the motor and touch the other end to your ear. Try this on the valve cover, near the middle of the motor under the head and down by the oil pan. You can put an earplug in your other ear. You should be able to tell where the clack is loudest and that will help you determine what to do next.

[sandsawmill14]

i wouldnt run it very long to do that test and at an idle ;)

[bushmechanic]

  Usually if it drops a valve it just goes dead on that cylinder unless the valve sticks into the piston then that might make a racket. When you pull the valve cover make sure all the valves look like they are in there respective places. Did you have any wet weather lately before you started it? You may have got water down in it and bent a connecting rod. Also an over fueling injector will give you a knock, notice any more smoke out of it than usual? 

[ehp]

Hope its not this but I had a 4-53 break the crank and that gave a loud knock

[sandsawmill14]

eph  did the engine vibrate like it was out of balance when the crank broke ??? i know the v8 diesels will raise more **** than 3 haints when they break but never broke one in an inline engine

[madmari]

I had a similar noise and used the wooden stick technique that grassfed speaks of. I was in a panic that i broke a piston, rings or a major component. The culprit? A loose exhaust clamp coming off the manifold.

[Wayne64SS]

I'm just finishing up rebuilding a 353 now. We may have to swap some parts when you get here (governor depending on type and flywheel) but thats all easy stuff. I kinda bought this on a whim for no good reason other than the love of detroits and then got it home to find it dropped 3 valves in cyl #2. So now its been torn right apart and completely rebuilt with a reconditioned head. Still got the old one if you wanna see some carnage. Anyway I can beat the hell out of $4800. Let me know if interested.

[jocco]

Many have given you good ideas: I will go a little further : Drain the oil and look for metal or aluminum,bronze etc (you can send a sample out and have it tested) If you find any of this well mark the clock with "time of death" Next pull the valve cover and look for what others said (valve spring, rocker, cam roller etc.) THEN START HER TAKE LARGE SCREW DRIVER PUSH DOWN ON THE INJECTOR  SPRING to cut that cylinder out of firing that will tell you which one, if any is dead. This is similar to pulling a plug wire on a distributor!! ;D You may have other problems but start here.

[grassfed]

Another old mechanic trick to check to check for dead cylinders is to spit on your finger and then tap the exhaust manifold at each cylinder exit. The spit will linger on the cold dead cylinder and sizzle on the good ones. The new way of doing this is to use an infrared thermometer "gun".

[ehp]

yes it shock but not as bad as you would think, I was not really thinking broken crank but when I got into the motor it sure was .

[jocco]

I have seen many engines still run with a broken crank : Some seemed ok at idle

yes it shock but not as bad as you would think, I was not really thinking broken crank but when I got into the motor it sure was .

[OntarioAl]

I know it is a sick feeling to the stomach when all of a sudden a smooth running engine develops a troubling noise.
The scenario is as follows;
1/ You pulled a load into the landing and left it idling (no problem)
2/ You then hit the throttle to winch in and "It sputtered and starting making a load clacking" sounds like it maybe a fuel starvation problem.
The other posts have given you a lot of good advice but It would not hurt to pull your filters and check for water the mild weather may have melted ice and associated "crud" in your fuel tank.
My thoughts
Al

[Plankton]

Update from the field, sure is nice having service up here.

My dad met me up here this morning to look at it with me we pulled the valve cover off everything looked perfect in there, bared the engine over and listened/watched. Nothing out of the ordinary. Tried cranking the starter, cranked slow then normal speed then tried to fire then siezed.

So we commenced taking roll cage and other panels off in preperation for pulling the engine. Going to get as far as I can today and hopefully pull it tommorow morningish.

Well go from there.

Any thoughts on what happened if it now is siezed? Oil pump gears stripped out maybe?

Thanks for all the responses so far, helping me understand more about all this. Internal engine work is brand new to me.

[tantoy]

blower lobes?

[jocco]

I am sorry  :( probably with out dis assembly you will never know. Your block, head other parts may be ok. The hard part is this; is it cheaper to rebuild? Do you have lots of work and is a new motor is the answer? Can you find a good used one??? NOW IF IT MAKES YOU FEEL BETTER ;D  A friend had a 440 running good, working daily, did some minor work to it than a load bang and the block split in half!! I had one (motor was well worn out) but running working ok. Going down a skid trail shut it off cruised a vain of wood (so much wood so little time) Got on hit the starter there was a loud noise equal to a bomb being dropped on me!!! After seeing I was still alive it would turn over but no go. Results broken crank also destroyed the center bearing web in block.

[jocco]

Oh check to see you don't have a starter or flywheel issue also bar it over in both direction before pulling motor.