Have a backhoe with a Yanmar S4D106 Turbo motor. Have noticed that if unit sets more than a week between starting the low pressure lamp will remain lit 4-7 seconds after it starts. Always worse in the winter, but worries me that engine is rotating ~100 times without oil to all critics points. Sensor is located higher up on motor so crank is probably getting sufficient oil sooner. Engine only has 2400 hours and in 4 years I have owned always use Full synthetic 10W-40 and Wix filters. Should I be concerned over this or am I just too anal?
Check your filter number and see if it has a anti drain back valve. Synthetic oil is great but it also would drain back easier then dino oil I have a forklift that does the same thing because it doesn't get used much