John McCurdy
Member
- Joined
- Sep 9, 2024
- Messages
- 22
- Fluid Motion Model
- R-25 SC
- Vessel Name
- Shooting Star
We were about 10 minutes into a lake cruise a couple of weeks ago in our R25 SC when the engine very abruptly died. No other indications: no overheat, no loss of oil, nothing on the Penta screen. After running through checklists we dropped anchor, spent the night, and got a tow back to the marina the next morning. On the second attempt to start the motor I got a warning on the Penta monitor that said, "“Sensor Failure: Crankshaft Timing Sensor.”
Back at the dock I ran all the fuses and discovered that the serpentine belt was shredded. Not broken, but shredded. I accessed the engine from the cabin, cleaned out pieces of belt, and replaced both belts. I should note that the serpentine belt had worked its way under belt 1 (the belt that drives the water pump), indicating that the engine was running when the belt failed. There were wires and strips of belt deeply lodged in the crankshaft grooves under belt 1. All accessory pullies turn freely.
After replacing both belts I returned to the abrupt stop checklist in the Penta manual...basically powered everything up, checked that there were no codes, and attempted a start. The starter engaged very hard, enough to send "shock" through the cabin, but the engine doesn't turn.
So the engine appears to be seized. I'm about to trailer the boat (which will be interesting with no motor) and drive it to Stewart and Stephenson in Houston and then begin searching for piggy banks to break open. But before I do all that I thought it would be worth sharing my situation and seeking input.
I'm not inclined to do anything very complex on my common rail engine. I need to take a much better look at the oil and try to determine if there's water or coolant in it. Other than that I'm about out of ideas. It's a strange situation. If the motor just seized underway I don't know how the belt would have shredded the way it did. It's possible that I lost the belt once underway and then there was a subsequent and unrelated engine failure, but that's a pretty bad day. I don't believe the engine would have shut down as abruptly as it did due to the belt failing, and without any other indications on the Penta screen. After consulting the manual, online forums, and Chat GPT I can't find anything to help analyze what happened. I'm not even 100% certain what's on the serpentine belt: it's driven by the crankshaft and has an automatic tensioner, the alternator, and another component that looks to me like the starter. But I'm told that the starter on that engine is mechanical, not belt. I still think it's a starter.
-John
Back at the dock I ran all the fuses and discovered that the serpentine belt was shredded. Not broken, but shredded. I accessed the engine from the cabin, cleaned out pieces of belt, and replaced both belts. I should note that the serpentine belt had worked its way under belt 1 (the belt that drives the water pump), indicating that the engine was running when the belt failed. There were wires and strips of belt deeply lodged in the crankshaft grooves under belt 1. All accessory pullies turn freely.
After replacing both belts I returned to the abrupt stop checklist in the Penta manual...basically powered everything up, checked that there were no codes, and attempted a start. The starter engaged very hard, enough to send "shock" through the cabin, but the engine doesn't turn.
So the engine appears to be seized. I'm about to trailer the boat (which will be interesting with no motor) and drive it to Stewart and Stephenson in Houston and then begin searching for piggy banks to break open. But before I do all that I thought it would be worth sharing my situation and seeking input.
I'm not inclined to do anything very complex on my common rail engine. I need to take a much better look at the oil and try to determine if there's water or coolant in it. Other than that I'm about out of ideas. It's a strange situation. If the motor just seized underway I don't know how the belt would have shredded the way it did. It's possible that I lost the belt once underway and then there was a subsequent and unrelated engine failure, but that's a pretty bad day. I don't believe the engine would have shut down as abruptly as it did due to the belt failing, and without any other indications on the Penta screen. After consulting the manual, online forums, and Chat GPT I can't find anything to help analyze what happened. I'm not even 100% certain what's on the serpentine belt: it's driven by the crankshaft and has an automatic tensioner, the alternator, and another component that looks to me like the starter. But I'm told that the starter on that engine is mechanical, not belt. I still think it's a starter.
-John