I have a pair of 2006 C9s in an express with 500 hours. When running there is a 'ticking' noise from the starboard motor. It seems to get quieter as the engine heats up and does not come from the port motor. It is clearly audible form the helm but not in the engine room as the engine noise drowns it out. It is fairly regular and is in synch with the RPMs although hard to hear once the turbos spool up. It does seem to internal (i.e. not a loose belt).
The starboard engine did get a new head at 450 hours. Any thoughts greatly appreciated.
I would inspect the operation of the lifters and pushrods to make sure everything is tight and normal. Also, check for any loose parts in the valve train assembly.
A bolt vibrated out of the lifter shaft on my 3196 requiring replacement of the camshaft, cylinder head, and entire valve train assembly.
Sounds like the valves could be out of adjustment. Talked to someone, I forget who, and this also happened on one of his cats in his boat. Tolerances too loose I believe and then when parts heat up and expand, noise lessens because there is less clearance. Let us know how you make out.
How often does cat recommend checking valve clearances on these motors?
(DISCLAIMER: I fix diesel truck engines, not boat engines, so this was just an educated guess.)
Tryin' to be the man, my dog think's I am. marine diesel service owner
New Head at 450 hr's ????,
Hate to ask, why???? What happened to the original head ??? Did they put in new injector's or put the old one's back in??? Have the head bolt's been re-torqued??? Warrantee????
I'd set the valve's, then check them hot (to make sure you don't have one sticking). See if the noise goes away, if not at least you've eliminated the valve set. After any major work that I do, I alway's recommend checking the valves after approx 50 hr's. At 50 jour's most of the in titial wear will have taken place. Valve adjustment should be part of you regular maintainence program, once a year any how. Might sound like overkill to some, but I'd much rather be safe than sorry. It also gives you a good reference for wear trend's. I may even be interested in a cylinder leak down test (again to check for a sticking valve).
Injector's can also give some strange sound's as well (improper spray pattern's, clogged pintles etc...), I'd start with the valves but don't discount anything. With the higher injection pressure's that are being used these day's, an injector will fail most commonly in the open position. If this happen's you have little time, and I mean little time, to correct the problem before you end up with a failure. An stuck injector in the open position equal's a literal "blow torch" on the top of that aluminum piston. If you don't find anything evident on the valve check, you may want to pull and check the injector's.Frank
I can barely spell "diesel" and what little I know is about DD 671's....BUT I had the same exact symptom in my rebuilt 671 with less than 400 hours and the "ticking" noise turned out to be bad/burnt valves. See pics......and I guess it's worthwhile to say that the previous rebuild was done by the OEM....as Frank mentioned, you should address this immediately....this engine required a rebuild after less than 400 hours....
Do you ever get the idea caterpillar does all their R&D after they put the engines in your boat and they fail? I sure do. After all, isnt it the diesel thats supposed to run forever? A new head at 450 hrs! C-7's people hate em, C-9's ? C-12's cant give a boat away with those engines. Cat has a lot of work to do if you ask me. They just seem to have failure after failure. I mean, how much preventative maintenance can one do? After all, you bought it to fish.......not fix. Hope you find the problem before it becomes too big. I would sure make cat come back and check it before I ran it.
Thanks for all the input guys. Luckily the 'ticking' turned out to be minor. For some reason cat paints the pulleys and as they were wearing they were creating the sound. That is the good news. The bad news is we uncovered some other stuff in the process....
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C-7's people hate em, C-9's ? C-12's cant give a boat away with those engines. Cat has a lot of work to do if you ask me. They just seem to have failure after failure. I mean, how much preventative maintenance can one do? After all, you bought it to fish.......not fix. Hope you find the problem before it becomes too big. I would sure make cat come back and check it before I ran it.