Narrative:

Climbing thru 31800 ft MSL, the #1 engine oil pressure dropped to 16 psi (well in the red). We got aural 'engine oil' warning and associated EICAS messages. It was my leg, so I had the first officer run the checklists, and we subsequently shut down the engine. I declared an emergency shortly after starting a descent because we could not maintain altitude. We turned back to ZZZ1 (our origin), and realized ZZZ2 was a much better choice. We conferred with our dispatch, and diverted to ZZZ2. Safe landing accomplished after completing all appropriate checklists. Callback conversation with reporter revealed the following information: the reporter said the engine was a general electric CF34-3b1 and the cause of the low oil pressure below the red line was a failed scavenge pump. The oil pressure transmitter was replaced, but the real problem was the failed scavenge pump. Callback conversation with reporter acn 640053 revealed the following information: the reporter was not certain of the failed component but believes the scavenge pump was the major cause and an oil cap gasket was also replaced.

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Original NASA ASRS Text

Title: A CL65 IN CLB AT FL318 DECLARED AN EMER AND DIVERTED DUE TO LOSS OF #1 ENGINE OIL PRESSURE. IN FLT ENGINE SHUTDOWN.

Narrative: CLBING THRU 31800 FT MSL, THE #1 ENG OIL PRESSURE DROPPED TO 16 PSI (WELL IN THE RED). WE GOT AURAL 'ENGINE OIL' WARNING AND ASSOCIATED EICAS MESSAGES. IT WAS MY LEG, SO I HAD THE FO RUN THE CHKLISTS, AND WE SUBSEQUENTLY SHUT DOWN THE ENGINE. I DECLARED AN EMER SHORTLY AFTER STARTING A DSCNT BECAUSE WE COULD NOT MAINTAIN ALT. WE TURNED BACK TO ZZZ1 (OUR ORIGIN), AND REALIZED ZZZ2 WAS A MUCH BETTER CHOICE. WE CONFERRED WITH OUR DISPATCH, AND DIVERTED TO ZZZ2. SAFE LNDG ACCOMPLISHED AFTER COMPLETING ALL APPROPRIATE CHKLISTS. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR SAID THE ENGINE WAS A GENERAL ELECTRIC CF34-3B1 AND THE CAUSE OF THE LOW OIL PRESSURE BELOW THE RED LINE WAS A FAILED SCAVENGE PUMP. THE OIL PRESSURE TRANSMITTER WAS REPLACED, BUT THE REAL PROB WAS THE FAILED SCAVENGE PUMP. CALLBACK CONVERSATION WITH RPTR ACN 640053 REVEALED THE FOLLOWING INFO: THE RPTR WAS NOT CERTAIN OF THE FAILED COMPONENT BUT BELIEVES THE SCAVENGE PUMP WAS THE MAJOR CAUSE AND AN OIL CAP GASKET WAS ALSO REPLACED.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.