Mechanical vs. Electric Engine Gauges

Faulty VDO oil pressure gauges

The photo above of the oil pressure gauges on our two engines was taken last summer as we were working our way through British Columbia. On the face of things, the oil pressure on the port engine is a little low and that of the starboard engine alarming. Is this the result of low oil level, a true oil pressure issue from bearings or oil pump, or a bad sensor?

In the absence of a back up system, we’d be on the phone to a diesel mechanic. Which is why we have been fitting Murphy Switchgauges to our yachts for the past 30 years.

Murhpy Switchgauge panel

These are mechanical gauges. No electrical bits to go out of synch. In our experience we’ve never seen one go bad. You can see on the upper left gauge that we have a standard 50PSI pressure on this engine (same for the other mill as well). That gives us a warm, fuzzy feeling. We know our little Deere’s are just fine. This winter, when we’re doing maintenance chores, we’ll replace our VDO electric senders.

Murphy gauges also have alarm contacts. You can set these to a pressure or temperature at which an electrical signal will be given. We typically adjust these just outside of our normal operating parameters, so we have immediate indication of change.

We’ve got Murphy gauges on engine oil pressure and temperature, gear oil temperature, engine coolant and engine oil level.

These engine room panels also have start and stop switches for each engine, handy for maintenance when it is inconvenient to run back and forth to the bridge.

Posted by Steve Dashew  (December 14, 2007)

Comments are closed.