Date: 201902
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Flight conditions: IMC
Light: Daylight
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Taxi
ATC / advisory: Ground ZZZ
Aircraft component: Turbine Engine
Component problem: Malfunctioning
Reporter organization: Air Carrier
Reporter function: Pilot Flying; Captain
Reporter qualification: Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Second reporter function: First Officer; Pilot Not Flying
Anomaly: Aircraft Equipment Problem Critical; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor; Ground Event / Encounter Other / Unknown
Detector: Person Air Traffic Control; Person Ground Personnel
When detected: Taxi
Result: Flight Crew Returned To Gate; General Maintenance Action
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Normal Engine start and push back. Push crew disconnected and salute received. We held position upon disconnecting from push crew with both engines at idle thrust for approximately 7 minutes. We obtained taxi clearance from Ground Control to taxi to Runway XX. Upon applying normal taxi thrust; I heard and felt some unusual sounds and vibrations coming from the engines but could not identify them. Within approximately 10 seconds from applying taxi thrust; we were informed by an adjacent tow crew and from Ground Control that our left engine was on fire. We had no indications in the cockpit of any problems with either engine. We proceeded to secure the left engine and get another confirmation from Ground Control that we did indeed still have a fire and to confirm which engine was on fire. We secured the left engine and called for ARFF (Aircraft Rescue and Fire Fighting) to respond to our aircraft. Prior to ARFF arriving we confirmed with Ground Control that the fire was extinguished. ARFF arrived and confirmed that the fire was extinguished and the aircraft was not in danger. ARFF released the aircraft and we were towed back to the gate.After the passengers were deplaned; the FO (First Officer) and I went outside to look at the left engine. A large amount of oil was observed and pooled below the core vent area and also dripping down to the fan exhaust area. [Maintenance Control] requested that the pilots do an engine run to 'burn' the oil away and check for further oil leakage; knowing full well a tail fire may occur again during the engine run. I refused to do the engine run for Maintenance.I would like to add a caution to Maintenance for suggesting that the pilots run an engine at the gate that was recently on fire. I did feel 'pushed' by Maintenance to run the engine and was uncomfortable to do so. The troubleshooting of the engine with an obvious problem should be carefully considered. Better coordination should have been thought through than the 'QUICK FIX'. For example; take the aircraft to an engine run area; have maintenance personnel fully briefed and have ARFF standing by just in case the engine catches fire again.I would also like to add that the [Station] Chief Pilot and the Duty Chief Pilot were both extremely helpful and contacted me almost immediately after the incident occurred. Their support; coordination and advice were extremely helpful.


Second narrative: We had 2 normal engine starts. After pushback the ground crew disconnected; we sat with both engines at idle for approximately 7 minutes to work TPS data. We obtained taxi clearance and as the Captain applied thrust to taxi; we heard over the radio from Ground and another aircraft tow crew that our left engine was on fire. We secured the left engine and confirmed from Ground Control that the fire was extinguished. ARFF (Aircraft Rescue and Fire Fighting) arrived and inspected and confirmed the fire was extinguished. We were then towed back to the gate by the ramp crew.After parking; the Captain and I went out to look at the number one engine. A large amount of oil was found pooled in the tail cone area in the core vent area and dripping in the fan exhaust area.


Synopsis: B737 flight crew reported experiencing an engine fire during taxi for takeoff.