Date: 202112
Local time of day: 1801-2400
Location: ZZZ.TRACON, US
Flight conditions: VMC
Light: Night
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Cruise
Airspace: Class A ZZZ
ATC / advisory: TRACON ZZZ
Aircraft component: Oil Filter
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Human factors: Troubleshooting; Situational Awareness
Second reporter function: Pilot Not Flying; First Officer
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Automation Aircraft Other Automation; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Inflight Shutdown; Flight Crew Diverted; Flight Crew Requested ATC Assistance / Clarification; General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: In cruise at FL370 from ZZZ to ZZZ1; an amber 'Oil Filter Bypass' light illuminated on our #1 engine. As PF (Pilot Flying) I called out 'my aircraft' and the FO (First Officer) ran the QRH procedure. No other abnormal indications were noted at that time. With a quick review of the procedure we realized we'd be pulling back the thrust lever and wouldn't be able to maintain altitude. [Priority handling was requested]; we told ATC a lower altitude was needed as we would become a single engine aircraft and wanted to divert to ZZZ2. We started a 1500 FPM descent and continued running the QRH procedure. The 'oil filter bypass' light did not extinguish by pulling the thrust lever back to idle so that led to the shutdown checklist. We secured the engine with the Engine Failure or Shutdown checklist; then went into the One Engine Inoperative Landing Checklist. While the FO was running that I changed the FMS to our new destination of ZZZ2; put ILS XXL into the box and notified Dispatch with a text message from the FMS. Once the engine inop checklist was complete I handed the aircraft over to the FO to fly and I completed the Non-Routine Landing Considerations checklist. We set up for the approach and I briefed it. After discussing with the FO; I took the aircraft back as PF for the approach and landing based on aircraft experience and recency of previous flying. We realized we were still too high and asked for a 360 to lose altitude; this also allowed us to burn more fuel since we'd be landing overweight plus would buy us a little more time to get caught up. One thing to note that was odd; around 15;000 ft. MSL in a descent and trying to slow to 250 kts with the speed brakes out; I felt a vibration in the rudder pedals for approximately 20-30 seconds. The vibration went away with the stowage of the speed brakes. We were vectored around until ready; and the Descent/Before Landing/Deferred Items checklists were completed. We were cleared for the approach in VFR weather; asked for a straight out missed approach procedure; confirmed that AARF was standing by and performed the single engine approach just as we've been taught in the simulator. Touched down softly approximately 500 lbs overweight; in the TDZ on center line; and made a left turn off to the clear the runway. Set the brakes; gave an update PA to the passengers and had [Operations] check out our #1 engine and the brakes for abnormalities or an overheat. After the 'all clear'; we taxied into the gate being followed by AARF. Once the Shutdown Checklist was complete; I gave another update PA to the passengers and they gathered their belongings to deplane. ZZZ2 Maintenance came on board and they were briefed on the event as well as the fact that in the Shutdown checklist we noted that the #1 engine had lost approximately 9 quarts of oil. Not sure when that happened as we didn't notice that in the air; and never had a 'low oil pressure' light until after the engine was shut down. I called Dispatch to discuss the event; then we had a 4 way conversation with Name in Maintenance and Name1 in Operations where the event was discussed and questions were answered. After the FAs (Flight Attendants) were debriefed and the FO did a post flight walk around; we called it a day and got a hotel.


Second narrative: While cruising at 37;000 ft.; we had an oil filter bypass light; and as directed by the checklist we had to shutdown the engine; [request priority]; and land single engine at ZZZ. Oil filter bypass blockage.


Synopsis: B737-800 flight crew reported the #1 engine Oil Filter Bypass light illuminated in flight; causing an in flight shut down of the engine and a diversion to make an overweight landing.