Engine making "clackity clack" noises

[Cheechako]

Originally Posted by hamburking

I thought I was the only one who listened to his diesel and heard all sorts of imaginary clanks, clunks, moans and thuds. What a relief.

Look for anything loose in a nearby locker.

haha...yep!

[reed1v]

Originally Posted by a64pilot

Loose valves usually "tick" and are usually very well timed the "clackity clack" is usually dirty injectors and is sort of a sporadic sound, old Redneck way to clean up injectors was automatic transmission fluid in the fuel, it's a high detergent oil, but best is to remove and have tested

Dont do that You will ruin the injectors.

[reed1v]

Originally Posted by macbeth

I'm just about to change the engine oil at the end of this summer season in my 15 year old Universal 25 HP diesel 3 cylinder engine. About 1500 hours on it.

When I took the cover off, I could distinctly hear a "clackity clack" noise. Fairly consistent at any rev speed.

Any suggestions as to what this might be ? Thanks. If you need more details, please respond. Could I record the noise and put it on this forum somehow ?

Normal sounds for a diesel. The valves, lifters, and slides all make noise. Ever hear an old diesel benz or new diesel trucks. In any event do NOT tighten anything unless you really know what your doing. Tolerances are real fine and over tightening will destroy your engine. If you really need to fuss with this engine pay the cost of having a real diesel mechanic listen to it. Maybe even take an oil sample in for analysis. Otherwise if you regularly change the oil, keep the fuel clean, and make sure it does not over or under heat, then it will last a long, long time. 80k hours not uncommon on small diesels; some even go up to over a half million hours without much fussing.

[a64pilot]

Originally Posted by reed1v

Dont do that You will ruin the injectors.

No, you won't, Marvel Mystery oil won't ruin injectors either, and if it's cold enough to be below the fuel wax point, 10% or so of gasoline won't hurt them either.
I'll never have my boat where wax precipitates out of the fuel myself.

[farm sail]

Originally Posted by Guy

Unfortunately valves tend to get tight not loose. While there is wear on the valve stem tips, rockers, lifters and cam, most often it's the valve seat and face that wear, causing the valve to sink in the head and reducing clearance.

gotta disagree there. I cant count the number of engines I have done or recomended valve adjustment due to loose ( and clacking ) valves.

valve adjustment with a solid lifter is definitely something to check. then again diesel engines do make a horrible racket when everything is right. if the noise is new or louder I would certainly be worried and investigate the change

[Shenandoah]

I agree with poster re Marvel Mystery Oil in the fuel. As they remove the sulfur from diesel fuel it reduces the lubrication that the fuel provides for the injection pump, etc. MMO is a great fuel system cleaner. I would also suggest rather than Sea Foam that you run a can of Lubro-Moly Diesel Purge through the fuel system. There are You Tube videos showing people doing it on cars. You tap into the system and run it straight until it is almost empty, then dump the rest in the tank. It reduces the noise (somewhat) on Mercedes diesels. Of course, a certain amount of the "clackety-clack" is normal.

[macbeth]

Changed oil this morning. NO clackity clack !!!!!!!!!!!! Maybe old oil was getting thin or used out ??

[Celestialsailor]

[QUOTE=macbeth;1942680] I could distinctly hear a "clackity clack" noise. QUOTE]

My guess is my ex-wife stowed away.

[reed1v]

Originally Posted by macbeth

Changed oil this morning. NO clackity clack !!!!!!!!!!!! Maybe old oil was getting thin or used out ??

Usually old oil will be full of crud, black, and heavy. Unlike gas engines where old oil may actually be good for the engine, not good for diesel. Perhaps you did not have enough oil in the engine.

[Shenandoah]

Agree with reed1v. Level was probably down. Also, sounds like you need to shorten your oil change intervals. Oil and filters are relatively cheap. I have become a believer in synthetic oil in diesels. My Ford F-250 7.3 needs 16 quarts, so it's a pretty expensive proposition. Not so on a small marine diesel with much smaller capacity.

[reed1v]

Originally Posted by farm sail

gotta disagree there. I cant count the number of engines I have done or recomended valve adjustment due to loose ( and clacking ) valves.

valve adjustment with a solid lifter is definitely something to check. then again diesel engines do make a horrible racket when everything is right. if the noise is new or louder I would certainly be worried and investigate the change

Yup, never heard of a self tightening engine. Kind of contrary to basic engineering realities. On sailboats, given the low hours they are subject to, its not even a relevant issue. Again, spend the $100 bucks to learn what a diesel should sound like, what your oil is telling you, and what the diesel mechanic thinks of your engine. A small, well running diesel makes a terrible racket, like a gum ball machine gone wild. If its not making those noises, I would be worried(excess oil, over heated, and so forth.)

[a64pilot]

Originally Posted by macbeth

Changed oil this morning. NO clackity clack !!!!!!!!!!!! Maybe old oil was getting thin or used out ??

OK, so you have hydraulic lifters then?


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[model 10]

Originally Posted by reed1v

Yup, never heard of a self tightening engine. Kind of contrary to basic engineering realities.)

Really? Where does the valve go if the valve face and the seat wear? Perhaps you should re-think your reality.

[Celestialsailor]

Originally Posted by Guy

Really? Where does the valve go if the valve face and the seat wear? Perhaps you should re-think your reality.

In another life I was a motorcycle mechanic at two dealerships. After 1000 miles of running a new bike, almost all valve clearances would be less or tight.
Not the first time Reed has spouted off about an imaginary fact.

[farm sail]

Originally Posted by Celestialsailor

In another life I was a motorcycle mechanic at two dealerships. After 1000 miles of running a new bike, almost all valve clearances would be less or tight.
Not the first time Reed has spouted off about an imaginary fact.

not an absolute, it can go either way sometime valve clearance will increase other times it can decrease. some design are more likely to go one way or the other. but not always