What was found
DURING CRUISE AT 340FL, NOTICED THE RIGHT ENG OIL PRESSURE AT 29 & DROPPING WHILE RT OIL QUANTITY WAS 2 & ALSO DROPPING. TEMP REMAINED NORMAL, DIVERTED. AT BLOCK-IN, RIGHT ENGINE OIL QTY WAS 2 QTS, SETTLED AFTER 5 MINUTES TO 14 QTS. FOUND OIL SERVICE CAP NOT INSTALLED. IT IS HINGED AND WAS ATTACHED, BUT OPEN. INSPECTED ENGINE AND OIL SYSTEM IAW FIM 71-05-FAULT TREE 863. NO DEFECTS NOTED. CLEANED OIL RESIDUE AND SERVICED THE RT ENGINE TO FULL IAW AMM 12-13-01. RAN THE RT ENGINE IAW ENGINE RUN CHECKLIST, ALL PARAMETERS OK. OK FOR SERVICE.