41PC Cummins Hi-temp/Low oil pressure alarm, help!


Hey gang,

On my 1999 Formula 41PC I have twin Cummins 6CTAs - they run great - I just bought the boat last year but I'm having this annoying alarm problem.

My low oil pressure / hi-temp alarm just goes off randomly when cruising, even when everything is well within range. Frequently, I will be at cruising speed, running 1800-2000rpms, temps in the 160-170's, oil pressure in the 40's, and the alarm will just randomly go off forcing me to silence it. The previous owner said he had this issue for years with the boat but never got it fixed.

If that isn't annoying enough, when I am parking the boat in my slip, I use the shifters to bump in and out of gear to angle into my spot... while doing this, I bump from forward to reverse in both motors as necessary, this triggers the alarm again, every single time I bump in and out of gear. The only thing I have not figured out if it is just either the starboard or port motor that is the culprit (or both) and I plan to investigate this more this weekend.

Have any of you had this problem before or have any clue what could be causing this? I am baffled as the motors run great, never overheat and have great pressures, especially given how old the boat is. These motors have been very well taken care of.
 
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Mine does that too. We haven’t had the opportunity to run it much so I haven’t worked on it yet. Same engines. Right now I have a leak somewhere so that is my priority so the boat doesn’t sink…
 
Mine does that too. We haven?t had the opportunity to run it much so I haven?t worked on it yet. Same engines. Right now I have a leak somewhere so that is my priority so the boat doesn?t sink?


Ahhh, after some googling I found the answer. Apparently the 6BTA and 6CTA's are super sensitive to oil levels - so a couple of fixes people posted about:

1. the 6CTA's pan holds 14-18 quarts of oil, try adding a quart at a time till the alarm stops going off, one guy said 16 was the sweet spot for him
2. Ensure idle is 700+ rpms, some said the sweet spot was 8-900
3. Add a 2 watt, 10 ohm resistor to the oil pressure sensor wire behind the alarm - this was per Tony Athens from SBMAR - apparently this bumps up the signal just enough to stop the annoying alarm but still allows to proper REAL alarming during actual low pressure events
 
Thanks for posting this. Sounds like some fairly easy solutions. Although I really don’t want to increase the idle RPM much since the boat moves like crazy when you put it in gear now. I would trust Tony Athens. He really knows Cummins.
 
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