engine chatter

[saloi]

I have a Westerbeke 55a on my 32 ft sailboat. It has a chatter noise in neutral at low rpms The same problem exists also in gear only more pronounced.It all seems to go away at abou 1300 to 1400 rpms...does any one would like to volunteer some input as to the reason why...I always assumed it was normal.

[delmarrey]

It could be a loose mount some where. Either the motor mount, alternator, pump or what ever. I''d be checking all your bolts around the motor.

Metal rubbing against metal will make a chattering noise. I'd check the shaft coupler first.

BTW- Welcome aboard!

[Chief Engineer]

If it sounds like rocks in a coffee can it is the vibration dampener...most likely

[NCboatrx]

If you have a Hurth (ZF) transmission, it is not unusual for these small mechanical transmissions to rattle at idle and just above speeds. The rattle generally has dissappeared by about 1200RPM on a 3 cylinder engine.

The other thing that may be causing your rattle (chatter) is the damper plate. Westerbeke (and many other companies) use a damper plate with springs and eventally these springs wear and become loose in their housing. This also causes the noise that you have described.

[SUGILITE]

I want to thank everyone for their suggestions. In an effort to complete this subject for someone else that may have the problem I will document a possible solution.

I disucssed the problem with a local service mananager for Volvo engines. He was very familiar with the problem and said the cause was the low idle speed adjustment was set too low. The fix was to bring the engine up to operating temperature, then idle the engine and set the low idle to 800-850 rpm.

I will not be able to actually try this until I return to the boat next month, but I do remember that the engine does idle around 600 rpm which is quite a bit lower than the recommended speed.

[The Mons]

I have a 1986 Volvo 2003 engine. It started doing the chattering thing. I adjusted the valve clearances and it is much quieter now. The manual says that you're actually suppose to check the clearances on a regular basis. Every 50 hours if I remember correctly.

[SUGILITE]

Please ignor my prior post. It was meant for another discussion group. Got confused I guess.