Date: 201906
Local time of day: 0001-0600
Location: ZZZ.ARTCC, US
Flight conditions: VMC
Aircraft: MD-83
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
ATC / advisory: Center ZZZ
Aircraft component: Turbine Engine
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Not Flying
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Second reporter function: Pilot Flying; Captain
Anomaly: Aircraft Equipment Problem Critical
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Flight Crew Landed As Precaution; Flight Crew Inflight Shutdown; Flight Crew Diverted; Flight Crew Requested ATC Assistance / Clarification; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Left oil temp started fluctuating. Left wing tank fuel temp approximately 32 [degrees] Celsius. [I] thought that a fuel heat valve was possibly cycling without illuminating. Left engine oil quantity indicated 13 quarts with no fluctuation. Pulled up the 'oil temperature high' QRH procedure just in case we started having a high oil temperature indication. After navigating to the 'oil temperature high' QRH procedure; the oil temperature made its first excursion to approximately 135 [degrees] Celsius. We executed the 'oil temperature high' QRH procedure and initially thought we were regaining control of the oil temperature. Then during the execution of the procedure the oil temp spiked through 165 [degrees] Celsius and then became erratic eventually indicating somewhere between 193 [degrees] Celsius to 199 [degrees] Celsius. We went to step 2 of the 'oil temperature high QRH' and executed the 'oil temperature exceeds 165 [degrees] Celsius at any time' portion of the checklist. This directed us to the 'in-flight shutdown checklist.' The Captain requested a descent to 10;000 ft. after determining that there were no significant obstruction or terrain threats. We completed the 'Single Engine Operation Checklist' and then were directed to the 'Non-routine Landing Considerations Checklist.' We were able to contact Dispatch; Operations; and informed the flight attendants and passengers that we would be making a 'precautionary landing' as per the non-routine landing considerations. We acquired a discrete ARFF frequency from Center to use upon landing. The single engine approach and landing was completed uneventfully. After landing; the Captain set the parking brake; stowed the spoilers; and made a PA to the passengers to remain seated while I coordinated an inspection from ARFF. ARFF vehicles inspected our left engine for smoke/fire/fluid leakage and reported no anomalies. We were escorted to the gate by ground vehicles. Operations personnel were in place and ready to accept the aircraft and passengers upon arrival.


Second narrative: [Report narrative contained no additional information.]


Synopsis: MD-83 flight crew reported diverting to an alternate airport after an inflight shutdown related to high oil temperature in the left engine.