What mechanical diesel engine failure has occurred while underway?

Earl34Mainship said:

Wasn't underway; happened at my dock. About 9pm, I heard the 370HP Yanmar engine running; had not been on the boat that day. Boarded boat, engine didn't answer helm commands. Opened hatch smelled burning insulation. Fortunately the Yanmar tech has shown me how to shut down using solenoid. Yanmar tech discovered shorted (ground/yellow) butt connector in a wiring harness that shorted to the red wire and engaged the starter. Starter fried; some smoke damage, but not enough to cause fire suppression system to discharge. Tech explained that even though the DC panel Mail is off, DC is still going to the engine and the engine can start even if no one hits the start switch. Full story in next BoatUS magazine.

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That's not necessarily normal...certainly not on most of the boats I have owned or ran. Was that way on my current boat until I corrected it because it's "dangerous".

One of the things learned at the dock and not off shore somewhere... How did you correct this in your boat?

Earl34Mainship said:

One of the things learned at the dock and not off shore somewhere... How did you correct this in your boat?

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I have battery switches...one works the main panel from the house batts...one is next to the start batt.

When the start batt switch is off...the engine circuits are dead.

Ideally you have fuses or switches that isolate the batteries to withing a foot or so of them so you can't have any high amperage 12v arcing.

In 2001 Riviera 36 dropped an exhaust valve on port Cummins 6BTA 5.9 M3 cruising at 20kn. Clouds of white smoke. Continued for the weekend on stbd only and motored home at 7.5kn. Started the port motor at the last moment, for docking. Needed new piston, rings reman head and honed bore but was all done in-frame.

On current single engined boat the starter solenoid failed at anchor 10 miles from home. We got a tow home at 7kn - very quiet and economical!

Thanks psneeld... I'll look into switching the battery... for the time being, I've been turning off the rotary DC main switch, but that switch needs to stay on when we're overnighting on the boat... the separate batt switch is the better fix... thanks...

I'll add in my friends experience since I was on the boat at the time, Cummins 6B, 250HP twins, heading out offshore fishing and one hard injector line sprung a leak and not at the connection point but in the middle. After many years and vibration wore a thin spot. Came back on one.
I do think good scheduled maintenance can eliminate most issue, and there are those ones that are hard to plan around.

on a 1985 Volvo Penta 165 Hp engine had a engine circulating pump shaft bearing freeze up and twisted the shaft in half dropping the belt pulley into the bilge. Saw it happen on engine room camera.

On a 1979 Volvo Penta 135 Hp had the starter burn up trying to start the engine after anchoring all night and wave action pushed water into the engine through the exhaust.

Bay Pelican shut down 10 miles off the coast of Grenada from an air leak in fuel line. She had gone for 2 1/2 hours before she shut down. Fortunately we were able to put an electric fuel pump in line so that the fuel lines were pressurized and stopped sucking air in and made it to a marina. Scary to say the least entering a marina knowing that the engine could shut down at any second.

Marty

I ma now motivated to change my raw water hoses, which have been on my "to do" list. Anyway...

Low oil pressure alarm went off after taking delivery. I was taking the boat home and noticed lots of oil in the bilge. Found out later that there was a hole in the oil pan. Engine had to be pulled so I had all the gaskets replaced.

Early this week our starboard Detroit diesel 453 suddenly lost oil pressure while bringing boat down mobile bay to dauphin island (home port). We had just completed several miscellaneous repairs and upgrades in preparation for leaving on the great loop the next week. The low oil pressure alarm did not go off while running about 1500 rpms. I noticed the gauge drop and dropped it down to idle then to have the alarm sound. Made it in on one engine to our dock. My mechanic jumped on it and we both thought it was the oil pump. Turned out it was much worse in that we spun the idler shaft rear bearing and scored the block. Needless to say, trip is off for now while we pull the engine and rebuild. We had about 3500 hours on it. Good news is that it happened at home and not two weeks later out in the middle of the gulf while heading for tarpon springs, Florida. At least we are eating turkey at home and not the planned two Cornish hens that the boat oven would have accommodated.

kelbylinn said:

Early this week our starboard Detroit diesel 453 suddenly lost oil pressure while bringing boat down mobile bay to dauphin island (home port). We had just completed several miscellaneous repairs and upgrades in preparation for leaving on the great loop the next week. The low oil pressure alarm did not go off while running about 1500 rpms. I noticed the gauge drop and dropped it down to idle then to have the alarm sound. Made it in on one engine to our dock. My mechanic jumped on it and we both thought it was the oil pump. Turned out it was much worse in that we spun the idler shaft rear bearing and scored the block. Needless to say, trip is off for now while we pull the engine and rebuild. We had about 3500 hours on it. Good news is that it happened at home and not two weeks later out in the middle of the gulf while heading for tarpon springs, Florida. At least we are eating turkey at home and not the planned two Cornish hens that the boat oven would have accommodated.

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It's all about perspective. You have it. Be well!!

Shaft key constantly shearing for my mechanical tachometers on GM 6-71's. No solution except to keep replacing them.

Copper oil line running to mechanical oil pressure gauges leaking which dripped onto the autopilot electronics. Cut and re-flared the tubing.

Nothing really too serious on my 50 year old engines. Gotta love "Old School".

Bay Pelican, single engine 135 hp Lehman. 15 years, 2,500 hours. Air in fuel line resulting from new fuel tanks and new fuel lines. Overheating at near WOT, 2nd from front heat exchanger (for coolant) was caked with salt. Oil hose leak, failed hose clamp, requiring shut down and addition of more oil. Problems with stabilizers requiring shutdown of main engine to disconnect stabilizer belt (cut it).

Reported by PO. Yanmar 4JH3E premature oil cooler failure at 940 hours. Engine oil under pressure leaked into raw water system inside the cooler, and was pumped through the heat exchanger, water-lift muffler and out the exhaust. Alarm sounded when oil pressure was finally lost. Only sign of failure prior to the low oil pressure alarm would have been an oil slick behind the boat, if anyone had been watching for it. Cooler replaced and life is good at 1,600 hours. Seems there were a batch of bad oil coolers at one time, and the metallurgy was changed. Knock on wood (or bronze as the case may be)

I've seen many failures on equipment and trucks, but none on my boat. Taking care of the proper maintenance in a timely manner, paying attention to fluid levels and engine-room checks while underway all go a long way towards eliminating downtime.

Leaking coolers in my boating background. Lucky to have had and continue to have, a Marine Tex or similar on board. Able to patch the pinhole leaks, refill the reduction gear with motor oil and complete the voyage.

Al.

Knock wood no failures on my new-to-me trawler.
This just happend to a guy down the dock from me with T/Yanmar 6 cyl. He was at work after the weekend when the tow boat guy in the marina called. "Hey Matt, do you want me to shutdown your port engine?" The start keyswitch shorted out and started the engine by itself. The solenoid stayed latched in and burned up. Not a weekend goes by without the engine hatch up with some major repair work going on.

Reading this is worse than watching any horror movie. I wont sleep tonight.

High Wire said:

The start keyswitch shorted out and started the engine by itself. The solenoid stayed latched in and burned up.

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My old cruiser had a manual fuel and engine shutdown. The Morse controls were just pulled all the way back, thereby bringing fuel flow to zero on the governor on the 6-71s. You had to lift a small safety lever of course so you didn't accidentally shutdown while maneuvering.

So even if the starter solenoid shorted like in your example the engine wouldn't run. A good safety feature.

The scariest failure was loss of throttle while in a current, waiting for a drawbridge to open. Thankfully, I was waiting alone. Any attempt to throttle-up would result in the engine sputtering and threatening to stall. All I could do was slip it into gear and idle, hoping that it was enough to go against the current that was drifting me toward the bridge supports. After about a minute of trying to get away from the bridge at idle, I saw I was loosing the battle and drifting under one of the side arches. I was single-handing that day and didn't have a working auto-pilot to steer, so I ran to and from the helm and the mast-boom, antennas, dinghy crane, and anything else with a clearance issue. All I could hope for is an idle controlled drift, backwards under the bridge. I had my bow thruster to help with alignment between the arches, knowing that I might have enough clearance in the center, but I had to stay away from the curves of the arch on each side. I cleared the first arch with just a nick on the starboard roof when the boat rocked a bit, but it pulled the boat a bit sideways and now I had to align the boat again before it got caught on the next arch. Full rudder took care of aligning the stern, but using the bow thruster partially negated the action of the rudder so I couldn't use it until my pilothouse roof was already on the arch. Using the arch as a spring, a touch of the bow thruster helped the roof roll around it and clear the rest. Once she cleared the bridge, she was already in a turn and there was no oncoming traffic, so I just used the thruster to straighten it out and the idle speed with the current was enough to get me to the closest anchorage possibility, but by the time I arrived, the throttle problem (probably air in the fuel system) had dissipated. I anchored, changed the filters, tightened fittings, etc., but never knew what happened. No problem since.

I never saw the bridge-tenders face, but i'd guess he'd probably seen stranger things than that anyway.

makobuilders said:

My old cruiser had a manual fuel and engine shutdown. The Morse controls were just pulled all the way back, thereby bringing fuel flow to zero on the governor on the 6-71s. You had to lift a small safety lever of course so you didn't accidentally shutdown while maneuvering.

So even if the starter solenoid shorted like in your example the engine wouldn't run. A good safety feature.

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Given the number of fuel system related failures on engines with injection pumps and electronic fuel controls, there's a lot to be said for the bullet proof mechanical injection system on the older Detroits.

skidgear said:

Given the number of fuel system related failures on engines with injection pumps and electronic fuel controls, there's a lot to be said for the bullet proof mechanical injection system on the older Detroits.

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The one strange thing is that I could never get the old governors to settle down at idle. I adjusted them over and over but there was still that little bit or fluctuation at idle speed. Up and down. Was a little bit better when fully warmed up, but never smooth.

makobuilders said:

The one strange thing is that I could never get the old governors to settle down at idle. I adjusted them over and over but there was still that little bit or fluctuation at idle speed. Up and down. Was a little bit better when fully warmed up, but never smooth.

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There is a buffer screw on the govenor that adjust the slight rpm surging at idle.

River Cruiser said:

There is a buffer screw on the govenor that adjust the slight rpm surging at idle.

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Certainly I tried fine-tuning the buffer screw but it lacked precision. I would imagine that the design of an old Gray Marine 1940-ish governor differed from the later ones from the 70's or 80's. Were the latest designs more refined?