1985 Perkins 4.108 - Gulfstar

[Rubicon King]

I have a technical question that I simply cannot figure out. Our engine alarm will not stop blaring at the helm as long as the engine runs, for 1 min or 15 hours. When we start our engine, it runs great, no smoke, or trouble starting, no overheating, or under pressure issues, oil and water (cooling) are fine.

We installed a new alternator as the older one had a voltage regulator that was Kaput.... so the 65 Amp alternator is brand new and putting out 14.5 volts. The issue with the alarm started before replacing the alternator. It does have a small diode that comes off of the alternator, but the electronics shop tested it and said it was "fine" (no open circuit)

Any thoughts on where I should look? Any help is greatly appreciated

Mark

[Marathon1150]

The oil pressure sensor on our 4.108 failed and resulted in a continuous alarm. You might want to check the wiring to the senor and the sensor itself.

Good luck. It must be seriously annoying to have the alarm sounding continuously!

[tkeithlu]

Your engine alarm is likely to be either (or both) a over heat sensor (switch that closes at a fixed temperature) or an oil pressure sensor (only opens with a set minimal oil pressure). Both are pretty obvious on the engine, and are readily available at any ol' auto supply. You would normally expect the oil pressure alarm to sound when you turned the ignition on (supplied it power, and it's closed because there is no oil pressure. It should stop shortly after the engine starts and oil pressure goes up. The temperature sensor you shgould not hear from unless you run out of coolant or otherwise seriously overheat the engine.

So, it likely is the oil sensor that is bad. Take it to an auto shop and get one like it. It looks like this:

https://www.google.com/search?q=oil+...hrome&ie=UTF-8

[Rubicon King]

Th is for the replies. I’m headed t on the boat on sat and will quickly check the oil pressure sending unit on the port side.