Narrative:

During routine transmission of engine parameters by flight engineer he observed the #3 oil temperature to be well off scale on the high side. All 3 crew members were fairly certain the problem was a faulty gauge because of the position of the indicating needle, way off scale. In fact the first officer had a similar incident several years prior, which was the result of a shorted out wire. However, procedures were followed from the operating manual to bring the oil temperature down, to no avail, up to shutting down the engine. At this point we contacted our maintenance base in tulsa which proved to be a long, difficult task with poor communication available. They had no better alternative so we shut down the engine while in the vicinity of dtw. Because we had no other indications that there was any other problem with the engine, and our destination had very good WX and was more familiar to me, I made the decision to continue to ord, our destination. After landing, maintenance advised the #3 engine was covered with oil inside the cowling and suspected a blown bearing. At the time of this writing I still do not know the exact problem but have come to the conclusion that #3 engine was not as healthy as I suspected. For me, the lesson learned is that procedures are conservative, but need to be followed to the letter. When they say shut it down, do so and then land at the nearest suitable airport. Many times the problem will be a bad gauge, but the gauges are there to tell us our state of engine and it is safer to believe them than to second guess them.

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Original NASA ASRS Text

Title: #3 ENG OIL INDICATIONS MOTIVATED ENG SHUTDOWN OVER DTW. FLT CONTINUED TO ORD.

Narrative: DURING ROUTINE XMISSION OF ENG PARAMETERS BY FE HE OBSERVED THE #3 OIL TEMP TO BE WELL OFF SCALE ON THE HIGH SIDE. ALL 3 CREW MEMBERS WERE FAIRLY CERTAIN THE PROBLEM WAS A FAULTY GAUGE BECAUSE OF THE POS OF THE INDICATING NEEDLE, WAY OFF SCALE. IN FACT THE FO HAD A SIMILAR INCIDENT SEVERAL YEARS PRIOR, WHICH WAS THE RESULT OF A SHORTED OUT WIRE. HOWEVER, PROCS WERE FOLLOWED FROM THE OPERATING MANUAL TO BRING THE OIL TEMP DOWN, TO NO AVAIL, UP TO SHUTTING DOWN THE ENG. AT THIS POINT WE CONTACTED OUR MAINT BASE IN TULSA WHICH PROVED TO BE A LONG, DIFFICULT TASK WITH POOR COM AVAILABLE. THEY HAD NO BETTER ALTERNATIVE SO WE SHUT DOWN THE ENG WHILE IN THE VICINITY OF DTW. BECAUSE WE HAD NO OTHER INDICATIONS THAT THERE WAS ANY OTHER PROBLEM WITH THE ENG, AND OUR DEST HAD VERY GOOD WX AND WAS MORE FAMILIAR TO ME, I MADE THE DECISION TO CONTINUE TO ORD, OUR DEST. AFTER LNDG, MAINT ADVISED THE #3 ENG WAS COVERED WITH OIL INSIDE THE COWLING AND SUSPECTED A BLOWN BEARING. AT THE TIME OF THIS WRITING I STILL DO NOT KNOW THE EXACT PROBLEM BUT HAVE COME TO THE CONCLUSION THAT #3 ENG WAS NOT AS HEALTHY AS I SUSPECTED. FOR ME, THE LESSON LEARNED IS THAT PROCS ARE CONSERVATIVE, BUT NEED TO BE FOLLOWED TO THE LETTER. WHEN THEY SAY SHUT IT DOWN, DO SO AND THEN LAND AT THE NEAREST SUITABLE ARPT. MANY TIMES THE PROBLEM WILL BE A BAD GAUGE, BUT THE GAUGES ARE THERE TO TELL US OUR STATE OF ENG AND IT IS SAFER TO BELIEVE THEM THAN TO SECOND GUESS THEM.

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.