A B737-300 IN CRUISE AT FL310 DECLARED AN EMER AND DIVERTED. SHUT DOWN #1 ENG DUE TO ENG OIL TEMP EXCEEDING LIMITS. FAILED INDICATOR.

Narrative

AT CRUISE ALT I NOTICED HIGH OIL TEMP ON THE #1 ENG. WE BROKE OUT THE BOOK WHICH DIRECTED US TO THE INFLT ENG SHUTDOWN PROC. AS WE WERE GOING TO THIS PROC IN THE BOOK WE NOTICED THE OIL TEMP GAUGE WAS READING AT ZERO AND THEN THE GAUGE BLANKED OUT ALTOGETHER. WE SUSPECTED A GAUGE PROB AT THIS TIME AND ELECTED TO CONTACT MAINT. DURING THE CONNECT VIA COMMERCIAL RADIO THE GAUGE WENT BACK TO FULL TEMP SO WE IMMEDIATELY ACCOMPLISHED THE SHUTDOWN PROC. I HAD NOT BEEN PUT IN CONTACT WITH MAINT YET SO I ABORTED THAT AND REQUESTED DISPATCH 'CALL ME' VIA ACARS. DISPATCH CONTACTED US VIA COMMERCIAL RADIO AND ALSO PUT MAINT ON THE LINE. WE HAD BY THIS TIME DECLARED AN EMER WITH ZZZ CTR AND ELECTED TO DIVERT TO ZZZ2. WE NOTIFIED DISPATCH AND MAINT OF OUR INTENTIONS AND PROCEEDED TO ZZZ2. WE FOLLOWED ALL THE PROCS LISTED IN THE BOOK AND MADE A LNDG ON RWY 25R IN ZZZ2. WE TAXIED TO THE GATE WITHOUT FURTHER INCIDENT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE ENG WAS SHUT DOWN DUE TO HIGH OIL TEMP. THE RPTR SAID THE TEMP INDICATOR WAS SUSPECT AS IT DROPPED TO ZERO AND BLANKED OUT FOR A FEW MINS THEN CAME BACK WITH A TEMP THAT EXCEEDED LIMITS. THE RPTR STATED THAT IT PRESENTED A SERIOUS PROB OF TRUSTING THE INDICATOR OR IGNORING THE READINGS. THE RPTR SAID THE ENG WAS SHUT DOWN PER THE CHKLIST REQUIREMENTS AND MAINT CONFIRMED THE OIL TEMP SYS HAD FAILED.