Cummins Marine Diesel Repower Specialists › Forums › Cummins Marine Engines › 1999 Diamond C Series Loud Rattle

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  • March 4, 2022 at 3:58 pm #128035

    Doorpro
    Participant

    Hello all, I have joined the forum to ask for help with an annoying problem with my starboard Cummins 450c motor.

    Last month when starting the boat up the starboard started rattling and at first we thought it was the belt so that was changed along with the tensioner. Once that was done there was a definite noise from an Alternator bearing so that was changed.

    Now, once those little noises were taken care of all that was left was a noisy rattle from behind the front cover or at least that’s where it sounded like it was coming from but before having that removed the raw water pump was removed to make sure that the bearings in that were good and once that pump was removed the engine was ran with the belt also removed and there was still that rattling noise and it was very loud with the pump removed because of the gaping hole in the motor.

    So, I have had my mechanic remove the front cover and to his surprise all the gears looked great, were all tight and nothing was loose inside there, but the rattling still exists.

    I should have added that these motors are aboard my 2000 Silverton 453my and both motors have less than 900 hours on, but I really don’t want the timing cover and new seal replaced until we are sure that there’s nothing that were not seeing.

    Please if anyone has any experience with or knowledge about what may be going on here, I would be very grateful and I thank you all for reading.

    Thank you, Regards, Doug.

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  • May 17, 2022 at 6:38 pm #131815

    Tony Athens
    Moderator
    Vessel Name: Local Banks
    Engines: QSB 6.7 550 HP
    Location: Oxnard, CA
    Country: USA

    It’s pretty obvious that what I am looking at went poo-poo long ago and was trying to tell someone listening “something”.

    May 17, 2022 at 3:45 pm #131806

    donald roth
    Participant
    Vessel Name: Paumalu
    Engines: Cummins 6BT 180 hp
    Location: where the fish are!
    Country: United States

    My ears are shot, so I didnā€™t hear it in time, but this ring popped off the vanes of the circ pump and eventually destroyed the seal, resulting in an overheat.

    May 13, 2022 at 6:42 pm #131654

    Doorpro
    Participant

    RPM’s

    Well, I adjusted the idle speed up and it helped somewhat but to get rid of the rattle completely the rpms have to be much to high and the thing would slam into gear so I don’t want that but it did need a slight adjustment.

    Thank you again.

    May 5, 2022 at 5:18 am #131268

    lpmcc
    Participant

    I asked, as I know from personal experience, that if the idle rpm is too low in these engines, they do rattle a bit.Ā  I do not have any other ideas.Ā  Possible just adjust your idle speed up a tad and see how that works?

     

    May 4, 2022 at 3:41 pm #131255

    Doorpro
    Participant

    All rpms?

    IPMCC, can you please let me know what you were thinking when you asked about the rattle being there are all rpm’s. is there something else that I could look at now that I have answered you correctly and that the rattle stops when the engines are revved slightly. Thanks, Doug.

    May 3, 2022 at 5:42 am #131183

    Francis Valerio
    Participant
    Vessel Name: overslept
    Engines: Twin 4BT CPL741
    Location: Massapequa Park, New York Long Island
    Country: USA

    I still say it is your front gear train…

    even tho I posted a comparison sound file and the recording did not sound the same, I am telling you that in person BOTH my engines have the identical clatter going on.

     

    You could check the belt tension itself and see if that is where the problem is coming from.Ā  That would also make sense to clear up at above idle RPM.Ā  The gear clatter does the same thing

    May 1, 2022 at 8:43 am #131123

    Doorpro
    Participant

    Belt Guard

    Morning Rob,

    yes, the belt guard was removed to get to the belt, tensioner and alternator so it was not in the mix but a great thought. It honestly sounds like something loose on the outside of the motor but goes away when i raise the rpm’s. I’ll attach the sound file again.

    Thank you.

    Doug.

    May 1, 2022 at 3:14 am #131115

    Rob Schepis
    Forum Moderator
    Vessel Name: Tenacious
    Engines: 6BTA 5.9 330's - "Seaboard Style"
    Location: Long Island, NY
    Country: USA

    This very well may have been covered – have you investigated the belt guards?

    April 30, 2022 at 12:06 pm #131106

    Doorpro
    Participant

    Expasion Tank

    Ok, I have checked the metal expansion tank and the plastic overflow tank attached to the belt/pulley guard. The metal header that I think that you are talking about has four bolts attaching it to a bracket and they are upon rubber grommets so no noise coming from there. I was so hopeful and thank you for the thought.

    Picture attached.

    Regards,

    Doug.

    April 30, 2022 at 8:58 am #131101

    Doorpro
    Participant

    Great idea, I’ll run the motor and check today. I think that there’s two plastic tanks bolted to the belt cover but I’m hoping that there are metal ones on top as you suggest. Thank you nauti-est

    April 30, 2022 at 5:41 am #131078

    Nauti-est
    Participant
    Engines: 6BTA 5.9 370
    Location: Michigan
    Country: US

    Check coolant expansion tank.

    On my 6BTAā€™s, the coolant expansion tank on both engines have sheared one of three mounting bolts, several times. The one towards the center of the engine right beside the injectors. I know not all expansion tanks on these engines are the same, some are mounted at front of the engine laying transverse, mine are above and lengthwise to the engine. You may want to take a look at that. There are two mounting bolts on the right side very easy to access. The single bolt to the center of the engine, near injectors, has been my problem.Ā <br /><br />

    just a thought for you to look into.

    April 29, 2022 at 4:07 pm #131073

    Doorpro
    Participant

    Just a thought

    Hello all,

    I have had time to look over this problem again and have not managed to get anyone new to come out and look at this issue, but I have noticed one thing that Is different than I was led to believe and the first question when I started this post was from IPMCC and he asked if the rattle is there at all rpms and my mechanic had told me that it was.

    I had a chance to listen again today while running the motors for about half an hour and that is not true. The rattle goes away when i kick the revs up just a tad. When I get the motors out of idle the rattle goes away and I hope that someone is still watching this post and can tell me what the cause may be now that I have answered the first question correctly.

    Thank you all.

    Regards, Doug.

    April 14, 2022 at 3:26 pm #130419

    Doorpro
    Participant

    Final Thought

    Hi all,

    it looks like were done with this post although the rattling is still there. It does seem quieter now but it’s still there.

    I just wanted to take the time to thank everyone for all the great thoughts and things to look for and after looking into this issue more than I expected It Is quite clear that it’s a bracket or something hanging loose and thus far doing no damage.

    I hope that my newbie presence didn’t to the forum didn’t annoy anyone and want you all to know that I did take every comment to heart and looked into each and every idea and two mechanics also couldn’t find the problem.

    I also found out what a glenndinnig unit is and that my syncing is controlled by my electronic controls so that discounted another place that a rattle may have come from.

    So, thank you all.

    Regards,

    Doug.

    2 users thanked author for this post.
    Francis Valerio, Rob Schepis
    April 13, 2022 at 1:39 pm #130368

    Doorpro
    Participant

    Glenndening Unit

    Hi all,

    I am still wondering if I have a Glenndening unit that may be rattling as Neto suggested or if my “sync” needs are controlled by the Morse electronic controls as I suspect.

    I am terribly sorry to keep on about this, but could anyone please let me know where a Glenndening unit may be attached to my starboard motor so that if there is one I can discount it from my rattling issue.

    Regards,

    Doug.

    April 13, 2022 at 1:33 pm #130367

    Doorpro
    Participant

    Please ignore

    Hi all,

    please ignore this last post to this section. I had inadvertantly added this issue to my original post which may have not been the best thing to do, so I started another post about the Morse KE-4 control issues and have sorted that one out. I am sorry.

    I will also keep updating this “rattle” problem once I find another mechanic to take a look.

    Regards,

    Doug.

    April 9, 2022 at 1:19 pm #130230

    Doorpro
    Participant

    Hello again,

    my boat is equipped with Morse KE-4 controls and nothing is near the motors so not driven by gears so that discounts the rattle from there but the top mount unit in the picture below is exactly what I have on the helm as are the other two items shown, Actuator (2) and the ECU.

    The top mount dual control is where all the lights are flashing and the alarm sounds until I click the central button under the flap which disengages the transmissions so this must be part of the problem but as stated the unfortunately the rattle doesn’t come from here.

    I have done all that I can do so If anyone knows how to stop the lights and alarm on the Morse system I would appreciate help and who knows when that is fixed the rattling may also go away and even though that sounds unlikely the issues are tied together somehow.

    Regards, Doug.

    April 9, 2022 at 9:40 am #130220

    Doorpro
    Participant

    I have looked

    Hi all,

    now that I have an idea of what the Glenndening unit looks like I took a look in the engine room and all that I can see are the two controllers (one for each motor) and when I follow the gables they go directly to the transmissions and the fuel injectors, I think I have that right.

    The problem is that I can’t find a separate unit that looks anything like what I’m looking for, but being that the alarm sounds and the lights flash up on the helm It has to be this. Any advise would be gratefully appreciated as usual and I have attached a pic.

    Regards,

    Doug.

    April 9, 2022 at 6:19 am #130205

    Doorpro
    Participant

    Glenndening Unit

    Hi all,

    I have had time to get my head back in gear and on this annoying rattle and the one thing that Neto mentioned and that I had no idea about was the “Glenndening Unit”, so I started nosing around on-line.

    I found a couple of posts that mentioned the head unit on the helm and how all the lights on it were flashing and the main alarm going off and an engine stalling, which happened to me last time out.

    Ever since this issue started the alarm on the helm screams when I turn on the engine control switch on the main panel and when I go up onto the flybridge all the lights are flashing on the twin control unit and it doesn’t stop until I click the button that allows the engines to be revved up whilst out of gear.

    Neto, I think that you may have something but I don’t know where to start and I am wondering if you or anyone else has any ideas because this all seams to coincidental.

    Regards,

    Doug.

    April 8, 2022 at 5:53 am #130174

    Doorpro
    Participant

    Sorry for my tardiness

    Hello all,

    I am sorry that I haven’t kept up on this post as the problem still exists even after having a couple of mechanics look at it.

    I have not been here lately because a couple of thieving bastards broke into my truck and in doing that they found a spare key to my wife’s new car so of course they made off with it and even though we got it back we’re still dealing with the dealer and our insurance agency. Man I hate dealerships.

    Anyway, I have checked things like the remote oils filter bracket that Ipmcc suggested and that’s fine. I really dont know what an engine sync unit is that Neto mentioned or where it would be but we do have one which I will bring up to the next mechanic.

    Thank you all and I’ll be in touch.

    Regards,

    Doug.

    March 20, 2022 at 3:24 pm #129028

    lpmcc
    Participant

    Remote Oil Filter Bracket?

    Does this engine have a remote oil filter mount? If so, check that the bolts are tight.Ā  They do come loose and the mount will rattle.

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