New Oil Pressure Sender
Caliber 40LRC owners, Sean and Geralyn, share their experiences and projects on Bliss.
02 August, 2011
Engine Maintenance
We have a Yanmar 4JH3E 50HP diesel. The manual calls for oil change every 150 hours. We knew the previous owner had changed the oil right before selling the boat at 460 hours.Our engine just passed 620 hours, so we decided it was time to change the oil. Rather than try to drain the oil out of the drain at the bottom of the engine, we used a manual oil pump inserted into the dipstick hole and sucked all the oil out (6 Qts). This is much easier than trying to fit something under the engine and prevent spillage everywhere. We took advantage and replaced the oil filter, which should be replaced every 300 hours. While the lubrication system was drained, we decided to try and fix another problem that we have been having with our oil pressure gauge. If we've been motoring for a while, the oil pressure gauge will slowly dip into the red. The first time, it happened on the way to Portland from Seattle, which was unnerving. After checking the oil, and playing with the throttle, we decided it was either a oil pressure sender problem or a wiring harness problem. The oil pressure sender reads the oil pressure at the engine crankcase and sends a signal to the gauge in the control panel in the cockpit. We bought a new oil pressure sender and replaced the old one. During our test motor yesterday, the pressure read correctly over an hour of motoring. Success! I'm glad it's not the wiring harness. We also replaced the secondary engine fuel filter. It needs to be replaced every 300 hours, so we will replace it next time the oil filter gets replaced. Since we had the engine compartment open, we also decided to replace the water pump impeller. There was nothing wrong with it, but with it's age unknown, we decided to replace it anyway. After careful inspection, we decided the old one was still in good condition, so we put it back in the spares kit in case of an impeller failure. An interesting note: When we purchased the boat, the spares inventory showed two secondary fuel filters. While doing spares inventory, we noticed one of the fuel filters was the wrong type for any application on board. So while we thought we had two spares on board, we really only had one.