Rotational noise at idle

[JohnnySeaRay82]

Hi guys I am looking for another opinion on a noise I have on my boat. I own a 1991 Sea Ray 200 with a 5.7 Mercruiser and Mercruiser Alpha outdrive. The noise I hear is a tick noise near the back of the engine every 3-5 seconds. At first I thought it was an exhaust leak, but I ruled that out. On further inspection i found the noise to be coming from the driveshaft/outdrive area.

I was guessing it to be a worn u joint on the drive shaft and figured I would check the gimble bearing while I had the drive off. But, is there a possibility that this noise could be a mis adjusted shift cable?

The tick/click noise is every 3-5 seconds at idle in nuetral and in drive, I does go away at cruising rpm 2600-3000 RPM. Any input would be apppreciated, thanks

John

 

[stonyloam]

Re: Rotational noise at idle

Could be an exhaust shutter clanking, if the rubber is worn off.

 

[Failproof]

Re: Rotational noise at idle

Exhaust shutter, drive coupler bolt, drive shaft splines, u-joint, lube the coupler and try again. Pull outdrive, and run engine. If still ticking then coupler forward somewhere!

 

[IanFS]

Re: Rotational noise at idle

Badly adjusted shift cable. The clicking is the clutch not fully disengaged. Adjust the shift.

 

[JohnnySeaRay82]

Re: Rotational noise at idle

Ok I guess the simplest thing is to adjust the shift cable and see if it still occurs. If so I will pull the drive and run it to see if the noise is still present. Ill keep you guys posted

 

[JohnnySeaRay82]

Re: Rotational noise at idle

OK I checked the shift cable adjustments and they were dead on. I removed the drive and checked both the gimble bearing and u joints, both checked ok and were well greased. I then ran the engine without water for a few seconds and the noise seems worse. I may have an exhaust leak and possible the noise is louder due to running with dry manifolds? im going to look after work later, any other thoughts?

 

[04fxdwgi]

Re: Rotational noise at idle

I would look at the exhaust shutters and see it the rubber coating is MIA. If it is MIA, then the ticking may possibly be the bare metal shutters tapping against the exhaust pipe, especially with no water, they will be louder.

 

[ktbarrentine]

Re: Rotational noise at idle

OK I checked the shift cable adjustments and they were dead on. I removed the drive and checked both the gimble bearing and u joints, both checked ok and were well greased. I then ran the engine without water for a few seconds and the noise seems worse. I may have an exhaust leak and possible the noise is louder due to running with dry manifolds? im going to look after work later, any other thoughts?

Not sure why you would want/need to do that! Running dry, even for a "few seconds" will trash your impeller. Careful there! (edit...just re-read and figured out your drive was off at the time..... whew!) I go with the exhaust shutter theory. Easy enough to check those.

 

[JohnnySeaRay82]

Re: Rotational noise at idle

Bingo guys good call it is def coming from the exhaust shudder. Is this something I should repair or just an annoyance?

 

[stonyloam]

Re: Rotational noise at idle

You should have functioning shutters to keep water from coming up into the exhaust manifold through the outdrive. I would say take a look at them and if they are in poor shape, replace them. #6 here: http://www.mercruiserparts.com/Show...8.png&inbr=1014&bnbr=370&bdesc=EXHAUST+SYSTEM

 

[JohnnySeaRay82]

Re: Rotational noise at idle

Thanks you guys are very helpful. Im gonna tear down tomorrow and order the parts