Cummins 6BTA 330 Left Key On…Then had oil explosion!

[kyleschoenthaler]

New to the forum and diesel boats. I’ve always been an outboard guy. 38 Californian with twin Cummins 6BTA 330 Diamond Series. Im learning as much as I can about it. I’ve taken it out a few times and has run flawlessly. I screwed up bad on Sunday though.

I left the keys on. Slipped the boat, shut the engines off from the flybridge and never went down and turned the keys off. Left it that way until the next day when I went to the boat and heard a clicking sound. Keys were on for almost 24 hours. Found the keys on, turned them off and the clicking stopped. Went down to engine room and it smelled of HOT electrical. Not burnt electrical, but very hot. Could not find the source. After 15 minutes of me freaking out I tried the motors, they fired right up and I felt better about the situation.

Now yesterday, I replaced all the fuel filters and decided to run the engines and makes sure everything looked good. Fired up, ran great, went down to engine room, everything looked/sounded great. Went back up top, engines idling for about 5 minutes when it started making a very odd noise, almost like a jet. Ran down to engine room, saw a mist in the air, crawled forward and got shot in the face by pressurized oil. Oil was shooting out of the side of the motor. Shut the engine down right away.

Lost a substantial amount of oil, a lot. It appears the a sensor on the side of the motor failed and oil was shooting out of it. I believe it is the oil pressure sender, but haven’t been able to verify it. It doesn’t look like ones I see online. Im hoping/assuming this sensor was the hot electrical smell I smelled. Im hoping I didn’t damage the engine.

2 Questions
1. What could I have hurt by leaving the keys on overnight. I first thought glowplugs, but I know Cummins don’t have glowplugs. What would be hot during the key on engine off process?

2. What part broke? Is it the oil pressure sender? See pictures please. I know pics aren’t the best, but I was scrambling last night after cleaning up over a gallon of oil in my bilge.

Thanks for any help. I know gas engines and outboards like the back of my hand, diesel is very foreign to me, but Im learning.

Topic

[Rob Schepis]

Sounds like you have no working audible (buzzer) alarm in the event of an alarm situation….

[Dan]

I would be wary of the cheap oil pressure senders, they have a tendency to fail and you may have the incorrect set point for an alarm to trigger, or it will activate at low engine speed driving you crazy, some them have a high pressure rating less than the engines produce, and in your case without alarms you would not know and, that could be fatal.

If it where my boat I would get the temperature and oil alarm sorted out as a priority, if your unsure how to track all that down as a temporary solution you could wire them to the fuel solenoid (fused) positive and a cheap piezo alarm until you get the correct wiring sorted out.

SMX Simple Low Oil Pressure Alarm Switch

Cummins VDO Temperature Sending Unit / Alarm Switch 250F 120C

[Paul]

Not sure what I was thinking …

Completely disregard this sentence in my reply. The oil pressure sender isn’t shown in the diagram.

Paul Hoffman wrote:

(Note, the oil gauge sender is dual pole in this diagram, not single pole, case ground like ours)

[kyleschoenthaler]

I do realize that, as I’ve noticed my sensors don’t look like the ones that are factory. I found the oil pressure sensor, it was $8. I replaced both engines’ sensors. Was down about a gallon of oil, so filled it up. Ran the motors tonight and took on a 10 mile run going thru all rpm’s and everything looks great. All pressures and temps are where they should be and it ran flawlessly again.

Thank you for this website. Im learning so much.

[Tony Athens]

You do realize you have non-factory wiring/sensors. It will not follow the factory diagram nor will factory VDO Sensors work. This This is Boat builder wiring.

Tony

[kyleschoenthaler]

Thanks

Thank you for the reply. I’ve got 2 new oil pressure sensors that I will install tonight and fill with oil and pray.

I’ve spent the last 2 nights cleaning up a huge oil mess in my engine room that was previously pretty much clean. Bummer.

Every boat I’ve ever owned always had an ignition alarm and this one does not. I have to believe it had one at some point, but Im going to make sure one is working soon.

I really appreciate the info you shared. Thank you again.

[Paul]

Looks exactly like the oil pressure sensor

I have a 1999 6BTA 5.9 M3 330HP – probably same engine as you do … First picture the three-way combo fuel/oil block on my starboard engine (inboard side) showing the oil pressure sensor on the left and the single wire/case ground sender for the oil pressure gauge on the right.

Second picture is the three-way combo block from one of Tony’s tips article. Third picture is another steal from one of Tony’s tips … the wiring diagram showing how the key being ‘on’ kept current going to your sensor while you were away (Note, the oil gauge sender is dual pole in this diagram, not single pole, case ground like ours)

Looks to me like you blew the oil pressure sensor which I believe was ‘seeing’ current when the key was left ‘on’. Strange there was no alarm sounding to remind you the key was in the ‘on’ position. I know when I first turn the key to ‘on’ I get the alarm and power to the gauges. Once I know those I working I proceed to ‘run’ to start the engine.

Might be worth checking all the other items that saw current overnight. I once blew the starter, air heaters, and fuel solenoid when an ignition got hung up when I was trying to restart an engine earlier this year.

[Author]

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