480CE Vibration between 800 -1100 rpms

[Lawrence Ross]

Ok need some help twin engine boat with 2004 480ce 6CTA engines with 5500 hours on them when starting and running the engines the are fine.

After about 1 hour of running I am getting a vibration on the Port engine only in gear above 800 rpms to 1100 rpms below that is fine and above that is fine.

I have changed the injectors with new ones thinking that may have been the problem some of the injectors were not spraying good that helped a little with asmoke issure on start up only.

Could this be a problem with the injection pump or a stickey injetion pump rail??

I need some helpwith what direction to go next.

Thanks

Larry

Topic

[rborkenstein]

Same problem

I have the exact same problem. Engines run great except between 820 and 950 rpm. In that fast idle range the port engine vibrates like crazy. Just replaces injectors, but that didn’t help. Mechanic thinks its the injection pump which we will have rebuilt. Can you provide an update on your issue? Was it in fact your pump? Are you all fixed now?

[Lawrence Ross]

stil having the problem

Hi Tony JUst got back to the boat issues Had a Knee replaced and could notget in the engine room until now I am moving the boat north for the summer. the problem is still with me

you talked about the motor mounts they were replaced two years ago at that time i talked to you about them and they were way down on the stringers.

the vibration is very very rough when it happens

do you have any injection shops on the east coast you know about that will work on this bosch electronic pump
thanks sorry for the long delay but life got in the way
Larry

[Tony Athens]

From what you are describing, IMO, send the pump to a certified pump shop..

BUT with that said, are you are 100% sure all of your ISOLATORS are 100%, correct top to bottom? They are now 14 yrs old, and just like “shocks on your car” they can only do their job so long before they cannot do it right anymore.

What is their job? To absorb linear vibration ( that is energy) and turn in into heat & then dissipate it thru their structure. That energy is highest in the RPM range you are having the issue in..

Tony

[Author]

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