Low oil pressue problem?

[Howard Morton]

Having just bought a 1984 C30 equipped with a Universal M25 (600 hrs), we had the local diesel guy go through it completely to determine its condition. Everything checked out fine, and the engine seems to run quite well. We generally use it only to get in and out of harbor, preferring of course sailing to motoring.One evening this wasn't possible. Got caught way out when the wind died, and we had to motor for a couple of hours. Engine temps were steady at around 190 degrees. Engine ran great, no problems. When we returned to port, and reduced speed to idle, the low pressure lights/buzzer sounded intermittently, seemingly in synch with the firing of the engine. Increasing speed caused the indications to immediately stop.What gives? Do we have a problem here, or is this normal once the engine has been used at normal operating temp for extended periods, and then slowed way down?Any insight appreciated.Howard

 

[Gordon Torresen]

Buzz

The warning buzzer is activated by three things, low oil pressure, high coolant temperature or low alternator output. Knowing for sure which of the three is making the buzzer sound could lead you to the fix for your problem. The 190F that you see is a little high, although the engine would love to run there. This may be an indication of high resistance in one of the cable connectors, at the engine or at the display panel. This could contribute to the buzzer sounding spuriously. A loose alternator belt could do it. A loss of oil viscosity related to the heat could also be a cause. A defective sender for the temperature or the oil perssure may be the answer. The buzzer should not sound unless something is wrong. Check through the items above and I'm sure you will find the answer in the alarms. Hopefully it is not the engine itself.