Grinding noise on shutdown

[Diatom]

Crossed Georgia Strait ~ 2 hours at 3600 RPM, fluids OK, Tmax 197F. No waves, couple of ferry wakes. On shutdown encountered persistent grinding-gears noise. Kill thrusters, engine - doesn't stop. Kill autopilot - stopped. Could not replicate the issue with restart/re-shutdown.

Anyone know what's going on?

/tmm

 

[knotflying]

If the autopilot is on and engaged and you are standing still that could be the noise you heard. If the heading was set differently than the boat was facing then the autopilot was turning the rudder hard to try and get back on heading. However this usually happens when you are underway and stop and drift and forget to turn off the autopilot engagement. I could see this mistake happening at anchor, but not in a slip, but stranger things have happened.

 

[ChrisJ]

Crossed Georgia Strait ~ 2 hours at 3600 RPM, fluids OK, Tmax 197F. No waves, couple of ferry wakes. On shutdown encountered persistent grinding-gears noise. Kill thrusters, engine - doesn't stop. Kill autopilot - stopped. Could not replicate the issue with restart/re-shutdown.

Anyone know what's going on?

/tmm

How long does the grinding noise you hear go on for?

CJ

 

[Diatom]

How long: grinding noise carried on until I killed autopilot screen.
I think Knotifying nailed it: I must have engaged heading-hold going upriver while I threw out the fenders, forgot to kill it while I U-turned to dock, dismissed impedance to turning/docking as river current having left the damned thing on. First instinct diverted me to focus on thrusters (have they eaten some flotsam?) - then gearing (am I stuck between reverse/neutral?) So I went all the way to shutdown with autopilot still trying to reverse my course.

No apparent ill effects - seems fine today.

/tmm

 

[dbsea]

this same thing happened to me to me the other day. Was crossing the canadian border by sidney spit heading into port sidney marina, and I got stopped by the RCMP boat. I came to a complete stop, but left the heading hold on mistakenly and i heard all kinds of crazy noises coming from the engine compartment and was in a panic as customs was also asking me for my nexus card and boat documentation. I realized later I had left the heading hold on, and since we were drifting around in the haro straight with a little wind, the auto pilot was going nuts trying to keep us on a course.