Strange starting issue - anyone else experienced?

Apr 6, 2013
139
Catalina 310 Annapolis
For the idiot newbie here (me) if my engine had actually run out of oil and not actually shut down, wouldn't I hear awful grinding sounds or something?
 
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Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
An oil pressure gauge is easy to add to the M25XPB. There's a fitting by the oil pan that you can screw a gauge into. See attached. I've got a picture somewhere. I'll also attach the corrected wiring for the pod and engine, although it's possible yours is wired differently, so you need to verify. It's a very confusing arrangement.
 

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Apr 6, 2013
139
Catalina 310 Annapolis
Thanks so much. Apparently, I am have chosen the route to diesel knowledge of doing stupid things then learning from my errors.
 
Oct 22, 2014
20,989
CAL 35 Cruiser #21 moored EVERETT WA
Don’t beat yourself up. Some of us choose to experiment. Some read books. Some take classes. I have heard there are special people born with diesel systems knowledge. I have not met one yet.
 
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Tom J

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Sep 30, 2008
2,301
Catalina 310 Quincy, MA
For the idiot newbie here (me) if my engine had actually run out of oil and not actually shut down, wouldn't I hear awful grinding sounds or something?
Probably. Best to shut the engine down, and check the oil level. Let the engine cool, then lean over the top and check for loose connections at the pressure switch, down near the starter. Adding zip ties to the wire harness can help secure the connections. As mentioned, there is a plug at the pressure switch fitting that can be removed to install a sending unit or a hard line for the gauge. The gauge I bought is a mechanical one, and I can install the pressure line where the plug is. I haven't figured out yet where to install the gauge. Probably somewhere on the bulkhead aft of the engine.
 
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Oct 3, 2011
825
Anam Cara Catalina 310 Hull #155 155 Lake Erie/Catawba Island
Thanks! I have a multi-meter and took an elementary sailboat electronics class but, hope this isn't a stupid question, but what would I test with the meter? I am a newbie to figuring out the diesel and electrical systems on my new to me boat but want to learn.
I bought the book 12 volt bible, and also electrical sailboat systems, got both on amazon, dirt cheap and worthy!
 
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Apr 6, 2013
139
Catalina 310 Annapolis
An oil pressure gauge is easy to add to the M25XPB. There's a fitting by the oil pan that you can screw a gauge into. See attached. I've got a picture somewhere. I'll also attach the corrected wiring for the pod and engine, although it's possible yours is wired differently, so you need to verify. It's a very confusing arrangement.
Very helpful. Thanks!
 

JRT

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Feb 14, 2017
2,037
Catalina 310 211 Lake Guntersville, AL
You can see the wires and connector on the bottom of the engine side between the head wall and engine side. put on an old tee shirt and led flashlight and you will see the sensor on the with 2 wires connected to it, I bet one is lose and the vibration is causing the alarm. I replaced mine with a marine connector, it was one of the only time ar repair went fast and easy with no drama. I encourage you to lay down on your side and just look around a bit in the area and you will see it.
 
Apr 6, 2013
139
Catalina 310 Annapolis
Thanks! I will. Btw, if I wanted to install a sending unit for an oil pressure gauge wouldn't that screw into a port on the engine in the same general area as the pressure guage? If so, being such a newbie, I would have to figure out how to wire it in to the existing wiring harness of that question makes any sense.
 
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Tom J

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Sep 30, 2008
2,301
Catalina 310 Quincy, MA
Thanks! I will. Btw, if I wanted to install a sending unit for an oil pressure gauge wouldn't that screw into a port on the engine in the same general area as the pressure guage? If so, being such a newbie, I would have to figure out how to wire it in to the existing wiring harness of that question makes any sense.
See my post #25. The port for the sending unit is located on the fitting that the oil pressure switch is mounted on. There is a plug in the fitting that can be removed to accept the sending unit.
Post #22 shows the wiring diagram for the pod at the helm, where the gauge will be mounted. You would have to run two wires from the pod to the sending unit, and wire the gauge and sending unit according to the unit's instructions. Running wires from the pod to the engine is a chore, and finding room on the pod for the oil pressure gauge might be a problem. You could also mount the gauge in a more convenient location, but that would require running a feed from a power source also.
I am choosing to install a mechanical gauge. It does not require a power source, and is very reliable.
 
Apr 6, 2013
139
Catalina 310 Annapolis
Great info. If you have any tips for where to find and how to install the mechanical guage, that would be great! Thanks.
 

Tom J

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Sep 30, 2008
2,301
Catalina 310 Quincy, MA
Great info. If you have any tips for where to find and how to install the mechanical guage, that would be great! Thanks.
You can find the gauge at NAPA or any automotive supply store. The gauge usually comes with an assortment of fittings to fit different ports. Since this is a Kubota diesel, you will need a metric fitting. Most come with flexible plastic tubing to run between the gauge and the engine. This tubing works fine, but can become brittle with age. Copper tubing can be used instead, just remember to make a coil of the tubing near the engine to dampen any vibrations. Typically the kit will have ferrules that slide over the tubing to seal it to the gauge and fitting.
You can also get brackets to mount the gauge, or drill a hole somewhere and mount the gauge in that.
 
Apr 6, 2013
139
Catalina 310 Annapolis
BTW - if anyone has already installed a mechanical oil pressure sensor on their Universal M-25 XPB and has photos, I would love to see them. Thanks!
 
Oct 22, 2014
20,989
CAL 35 Cruiser #21 moored EVERETT WA
Golly gee it was electrical.

Thanks for sharing your discovery. I think you are taking the first steps at becoming a boat owner / diesel mechanic.

The engine needs are pretty simple really:
  1. Air
  2. Clean fuel
  3. Compression
  4. Cooling
  5. Exhaust
If those are all available and functional then the only thing to stop the engine from doing it’s thing is electrical.

Looking forward to more post about your boat.
 
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Apr 6, 2013
139
Catalina 310 Annapolis
Thanks. I am very tempted to try the mechanical gauge but worried about some of the posts I have read online where people who have used them on their powerboats had issues with the lines running back to the gauge leaking....really interested to hear the experience of anyone who has done this successfully and with no issues and, ideally, to see a picture or two of the installation. I assume if I install one with the engine off and cool I won't have a major issue with an oil leak as I attach it to the port provide on the oil gallery.
 

RoyS

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Jun 3, 2012
1,739
Hunter 33 Steamboat Wharf, Hull, MA
IMHO an oil pressure gauge is more of a luxury than a necessity. A temperature gauge is far more necessary. You are unlikely to experience an oil pressure failure as long as there is oil in your crankcase. The only vulnerable place for a sudden oil leak and loss of oil is the oil filter; it is flimsy and exposed. If you take a quick look at your engine and the bilge under it before each day's outing you should be OK. On the other hand, all kinds of unforeseen and invisible problems can affect the cooling system, from broken impellers to a blocked raw water intake. I would be very uneasy with an added external oil line (flimsy and exposed) to a gauge. If you are going to install an oil pressure gauge, I would stay with the electrical model with the sending unit on the engine block.
 
Mar 6, 2008
1,078
Catalina 1999 C36 MKII #1787 Coyote Point Marina, CA.
Yes, it is normally open when pressure is low and closes the contacts when pressure developes. The contacts places a short across the buzzer and it then makes no sound. Replacing is easy, but requires a special socket available from auto stores. Using a vice grip is sure to damage the device. To test the pressure sender, disconnect both wires from it. Measure continuity. There should be none. Then run the engine and test continuity. There should be a short. If it passed these conditions, it is a good working device. You may have broken wire else where.
 

Tom J

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Sep 30, 2008
2,301
Catalina 310 Quincy, MA
IMHO an oil pressure gauge is more of a luxury than a necessity. A temperature gauge is far more necessary. You are unlikely to experience an oil pressure failure as long as there is oil in your crankcase. The only vulnerable place for a sudden oil leak and loss of oil is the oil filter; it is flimsy and exposed. If you take a quick look at your engine and the bilge under it before each day's outing you should be OK. On the other hand, all kinds of unforeseen and invisible problems can affect the cooling system, from broken impellers to a blocked raw water intake. I would be very uneasy with an added external oil line (flimsy and exposed) to a gauge. If you are going to install an oil pressure gauge, I would stay with the electrical model with the sending unit on the engine block.
All valid concerns. Due diligence is a must. Check the engine, above and below each day of use. To be honest, I have seen just as many sending units leak as the hard line to a gauge. A few years ago, the pressure switch itself on my Universal started leaking, and I replaced it. A couple of years ago, my brother in law's Volvo diesel leaked at the oil cooler, and while removing it, I found that both oil pressure sending units had been leaking for some time. Any system has it's vulnerabilities, as you mentioned.