As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN PROCESS OF PRE-FLIGHT INSPECTION NOTICED RIGHT ENGINE OIL FILTER BY-PASS INDICATOR PIN HAD POPPED. INSPECTED OIL FILTER AND TOOK SOAP SAMPLE (NEW OIL FILTER INSTALLED). AFTER TEST RUN AND LEAK CHECK, NOTICED PIN PARTIALLY POPPED AGAIN. REMOVED BY-PASS INDICATOR ASSEMBLY AND NOTICED MINIMAL RESISTANCE FOR PIN EXTENSION. REPLACED ASSEMBLY WITH NEW UNIT. DEFECTIVE UNIT HAS ASSEMBLY DATE OF 3Q/87. ADDITIONALLY THE FOLLOWING NUMBERS APPEAR ON ASSEMBLY:99193SOCN307246-4 N AND MFR 05228-7579668.