Date: 202201
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: B737-700
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Climb
Airspace: Class C ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: Turbine Engine
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; Captain
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Human factors: Troubleshooting
Second reporter function: First Officer; Pilot Flying
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Provided Assistance; Flight Crew Landed in Emergency Condition; Flight Crew Diverted; Flight Crew Requested ATC Assistance / Clarification; General Flight Cancelled / Delayed; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: ZZZ is a civilian and commercial high use field. ZZZ switched runways. We were able to brief and prepare for the new northbound flow; but it caused numerous operational issues; as many aircraft were waiting for arrivals to the old runway. We taxied single engine; due to congestion. Following startup of [Engine] #1; a slight split throttle situation was observed; but we only taxied forward the length of the aircraft so it was not significant or consistent to warrant further investigation. Compounding the limited ramp and ground space at ZZZ; ATC needed 20 miles separation for northbound departures. We were cleared for takeoff with an aircraft on final and another just clearing the runway. After transferring aircraft control; the PF (Pilot Flying) called set takeoff thrust with A/T (autothrottles) engaged and the PM (Pilot Monitoring) missed the 80-knot call; instead calling 90 knots. The #2 Engine had stabilized IVO (within 0.1-0.3 %) takeoff thrust at the 90-knot call. Since HOLD engaged; the PM attempted to manually match the N1's; but was unable to manually match the #1 Engine. During climb out; the #2 Engine would not advance beyond approximately 87% with AT engaged though the FMC and AT were commanding a higher %. The PM requested and granted control of the engines; disengaged the A/T and attempted to manually advance the #2 Engine to climb thrust. The engine would still not advance beyond approximately 87%; though the white command bar was responding correctly to the manual throttle input and the white arc was visible on the N1 gauge and the #1 engine reacted normally while physically matching the #2 throttle position. No other engine vibrations or anomalies were noted. After cockpit coordination; the PM requested priority handling; received clearance for a lower altitude than assigned and a vector off of the assigned SID. Using Crew coordination; we verified that each of us was seeing the same indications and response from the #2 engine. The PF placed the #2 Engine thrust lever to idle; we ran the checklist with a plan to divert to ZZZ1; while shooting a precautionary single engine approach and keeping the #2 Engine in idle; where it was operating stable and within parameters. We coordinated with ATC and ZZZ1 Operations; who assisted with a patch through to Dispatch Desk. We coordinated with the F/As (Flight Attendants); made a PA; prior to starting our approach into ZZZ1; ran numbers for a flaps 15 landing and ran brake cooling numbers which indicated a 50 minute at the gate cooling time. We transferred aircraft control and the Captain took over the PF duties; while shooting a precautionary single engine visual backed up with an ILS to XXL into ZZZ1. We touched down normally; taxied clear; coordinated with ARFF (Airport Rescue and Fire Fighting) #1; who indicated no anomalies were observed. We taxied uneventfully to the gate where the passengers deplaned normally to be accommodated on a later flight under the same flight number. We completed coordination with ZZZ1 Maintenance; Dispatch; Supervisor on Duty; Operations Center Chief Pilot on Call; Manager on Call and Scheduling; while completing Page XXXXXXXX of the logbook.


Second narrative: We were cleared for takeoff on Runway XX; with an aircraft on final and another just clearing the runway. After transferring aircraft control; as the PF (Pilot Flying); I called for takeoff thrust with the A/T (Autothrottle) engaged. The takeoff was completely normal; and I was unaware of any engine abnormalities until approximately 1;000 feet. During climb out; the #2 Engine would not advance beyond approximately 87% with A/T engaged; even though the FMC and A/T were commanding a higher rating by approximately 1-2%. The Captain (PM) requested and was granted control of the engines; disengaged the AT and attempted to gently advance the #2 Engine to climb thrust. The engine would still not advance beyond approximately 87%; though the white command bar was responding correctly to the manual throttle input. The white arc was visible on the N1 gauge and the #1 Engine reacted normally while physically matching the #2 throttle position. No other engine vibrations or anomalies were noted. After cockpit coordination; the PM (Pilot Monitoring) requested priority handling; received clearance for a lower altitude and a vector off the assigned SID. Using crew coordination; we verified that each of us were seeing the same indications and response from the #2 Engine. We decided to place the #2 engine thrust lever to idle; ran QRH the checklist with a plan to shoot a precautionary single engine approach to Runway XXL at ZZZ1; which was in sight at this time. The #2 Engine operated normally at idle; in a stable condition; within all expected parameters.  We coordinated with ATC; coordinated with ZZZ1 Operations who assisted with a patch through to Dispatch; coordinated with the F/As (Flight Attendants); made a PA prior to starting our approach into ZZZ1; ran numbers for a flaps 15 landing and ran brake cooling numbers which indicated a 50 minute cooling time; and safe to accomplish at the gate. We transferred A/C (aircraft) control and the Captain took over the PF duties for the precautionary single engine approach and landing. We touched down normally; taxied clear; coordinated with ARFF (Airport Rescue and Fire Fighting) #1 who observed nothing unusual about the #2 Engine. We taxied uneventfully to the gate where the passengers deplaned normally to be accommodated on a later flight. The Captain completed coordination with ZZZ1 Maintenance; Dispatch; Supervisor on Duty; Company Operations Chief Pilot on Call; Manager on Call; and I contacted Scheduling; to discuss a plan to complete the remainder of our trip.


Synopsis: B737 flight crew reported a diversion after engine power loss on takeoff.