Crunch crunch in gear....

[MarkA]

Update: I just spoke to a mechanic who:

1) Ruled out the damper plate since it would make the noise all the time,

2) Told me the sediment I found was perfectly normal, and even on the light side,

3) Told me it's common for three-cylinder motors to make the transmission sound bad as it accelerates through an rpm range if it's running rough while sounding fine at full speed, and recommended I try to replicate the sound by cracking the injectors one by one, and,

4) Suggested I rule out the cutlass bearing by unbolting the shaft and seeing if that makes the sound go away.

So here I go! Back to the boat.

Thanks to Tom at Harper's Marine, I'm feeling much better. Update later this evening.

 

[sailorman37]

If you have not found the cause, here is another idea from personal experience. I have a 30+ in Tampa Bay and if I don't use the boat for a short time, barnacles grow on the shaft and prop - those places without antifouling paint. Spinning the shaft slowly, by hand or under power, there is that crunchy sound for a while as they get ground down. It goes away, but it sounds bad at first.

 

[Emerald]

One more thought, make sure you don't have Captain Crunch down there munching on a bowl of cereal. Sorry, couldn't resist

 

[jgarmin098]

Another thought:

I once had a zinc slide down the shaft until it rubbed against the forward edge of the strut. It made a sort of grinding sound when in gear at idle and was lost in the engine noise at higher throttle settings. It could also be heard when sailing with the gear box in neutral and the prop free wheeling. (I know, always leave the gear box in reverse when sailing...)

Could it be so simple...?

'88 E-32-3