What was found
DURING CRUISE, SHORTLY AFTER DEPARTURE, PILOT NOTICED A FLUCTUATION IN THE OIL PRESSURE INDICATION. THE PRESSURE WAS INDICATING IN THE 40 PSI RANGE THEN WOULD DROP TO THE LOW 20'S OVER A FEW SECONDS THEN RETURN BACK TO THE 40'S. AS A PRECAUTION THE PILOT RETURNED TO THE AIRPORT OF ORIGIN. ANALYSIS OF THE ENGINE DATA SHOWED A FAULTY INDICATION BECAUSE OF THE "SAWTOOTH" DIGITAL PLOT ON A GRAPH OF THE PSI INDICATION. THE PREVIOUS FLIGHT THAT DAY SHOWED SIMILAR INDICATION FLUCTUATIONS WHEN IT'S DATA WAS REVIEWED BUT WAS NOT REPORTED. PREVIOUS FLIGHTS DURING THE WEEK SHOWED LITTLE TO NO FLUCTUATION IN THE DATA. REPLACEMENT OF THE OIL PRESSURE TRANSDUCER ELIMINATED THE FLUCTUATIONS AND OIL PRESSURE INDICATED STEADY.