F200 has knocking/rattling sound when running

[mvitiello]

If anyone can help I would greatly appreciate it. I have twin 2003 F200s with 450 hrs each and the port motor has developed a knocking/rattling sound when the motor is running above idle. It does not occur at dead idle but it almost always occurs when the engine is run (in gear or in neutral) above idle RPM. Almost like a harmonics vibration noise but i doubt thats it. The noise started early this season (about 30 hrs ago) and it may be getting a little louder but it's hard to tell. Even when the motor is making the noise is seems to be louder at some RPS and quiet or gone at others although, when I am running fast all the other noises make it hard to tell if the knocking rattling sound is still there. Also, the last time I ran the boat (20 minutes to get fuel) it did not make the noise at all. This was odd because, other than this trip, the noise is fairly consistent. The performance of the motor does not appear to be effected and it is otherwise running fine - good stream of water out the pisser hole and everything.
I made two 1-minute videos (one in gear and one in neutral) so people can hear my starboard motor (sounds fine) and then my port motor (with the noise i describe above). you can see the videos at the two youtube links below:

http://www.youtube.com/watch?v=_83jGwXJ4n4
http://www.youtube.com/watch?v=Xbh0bVvPAWk

Thanks much for any assistance anyone might have.
Michael

 

[robert graham]

Re: F200 has knocking/rattling sound when running

I'm not the expert on these motors but I understand there is a motor balancer on these that can sometimes go bad and rattle. Maybe do a forum search on balancers because I read about this here. Good Luck!

 

[seahorse5]

Re: F200 has knocking/rattling sound when running

I'm not the expert on these motors but I understand there is a motor balancer on these that can sometimes go bad and rattle.

The balancers are only on the 4-cylinder F150 motor, not the V-6's

 

[mvitiello]

Re: F200 has knocking/rattling sound when running

A mechanic took a look at the issue I describe above and told me (via the boat yard manager) that it's almost certainly a vertical shaft bearing that is starting to go. He said that it's actually a common problem on "these" motors and that even after they fix it, it's not unusual for the noise to come back in 2 years or so. By the way, about 15 minutes before I hauled the boat for the season I just started to hear the same noise coming from my other outboard too.

I saw another post on another forum that mentioned that you can't even notice this noise on most 2 strokes because of the normal operating noise so for that reason it's mostly a 4 stroke "problem." The question is, am I in danger of doing serious motor damage by running it as is - it sounds like there is not a big danger.

Also, my motors have 400 hrs on them and are on the original water pumps. I am thinking of trying to get one more season out of them (next summer) and doing both the water pumps and vertical shaft bearings when I haul out in Fall 2011. Does the bearing work add much to a water pump job or is most of the labor already factored in?

As always, thanks very much for any thoughts or comments.
Regards,
Michael

 

[robert graham]

Re: F200 has knocking/rattling sound when running

There are some "wave" washers on top of the water pump that take out the up and down play in the drive shaft. These are installed during water pump impellar replacement. If there is some play in the drive shaft it can make some knocking sound. When you do your pumps tell the guy about your knocking and to check for this play, which he should eliminate when he puts it back together. The drive shaft has a bushing part way down that requires some grease from time to time. I've had some knocking/vibration from that black plastic slide block that controls the throttle and shifter, might be worth a look. Lots of things it could hopefully be other than a big nasty "bad bearing" issue. Seems like if it was a bearing it wouldn't come and go, as you described. Good luck and let us know what you find!

 

[rodbolt]

Re: F200 has knocking/rattling sound when running

I have NEVER EVER NEVER EVER heard of ANY verticle bearing problems nor ever seen one go bad unless a seal leaks and lets oil out or water into the gearcase.
the wave washer and spacer wont affect anything in N but will allow the shaft to knock at an in gear idle but it goes away past about 1000 RPM in gear.
have you had the timing chain tensioners checked?
its either a 400 hour or 500 hour check.
they can allow the cam chain to rattle some.
doesnt hurt anything for a long time.
water pumps,T-stats and pressure control valve are already over 200 hours overdue for maint.
simply cannot picture ANY black plastic block thats common to both the shift and throttle.
post a part # of it.

 

[robert graham]

Re: F200 has knocking/rattling sound when running

That black plastic block thing that slides when you move the throttle, has some grease on it and it moves the throttle and gear shifter shaft lever. Mine was rattling at certain RPM's,I put like a rubber band around it to snug up the play in it and it never rattled again. I don't know how to post pictures. Maybe that chain tensioner you mentioned is making the noise.