Date: 201506
Local time of day: 0001-0600
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: B737 Undifferentiated or Other Model
Operator: Air Carrier
Mission: Passenger
Flight phase: Takeoff / Launch
ATC / advisory: Tower ZZZ
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: First Officer; Pilot Not Flying
Anomaly: Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Crew
When detected: Other takeoff roll
Result: Flight Crew Rejected Takeoff
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: Our flight was cleared to takeoff at ZZZ. Captain was the pilot flying. I took the runway; let engines stabilize at approximately 40 percent N1; selected Takeoff Go Around (TOGA); followed thrust levers up; and called 'Check Thrust.' The First Officer made minor adjustments to the thrust lever positions to achieve the desired takeoff thrust setting. Almost immediately; smoke emanated from the First officer's lower gasper vent and it smelled of oil. I called 'Reject' and discontinued the takeoff at a speed of less than 80 knots. The autobrakes never engaged. The smoke did not propagate further with the throttles at idle. We cleared the runway at taxiway Uniform; completed the Rejected Takeoff Checklist; contacted our cabin crew to see if there was also smoke in the cabin; and requested Fire Rescue Crew to examine the aircraft. The Lead Flight Attendant reported that there was no smoke in the cabin. The Rescue Crew found nothing visibly damaged with the aircraft. At no time did we observe any caution lights or secondary indications of engine; air conditioning pack; or any other systems malfunction. From the Brake Cooling Charts (160;000 lbs.; Sea Level; Speed 80 knots = N/A.) we determined that the aircraft was safe to taxi. I then made a PA announcement to assure the cabin crew and passengers of the safe state of the aircraft and of our intention to return to the gate. We then coordinated with ZZZ operations to obtain a gate assignment and to let maintenance know of our return. We proceeded to the gate uneventfully; shut down the aircraft in accordance with normal procedures; then contacted dispatch; the [company operations manager]; the crew desk. We also debriefed both local Maintenance at ZZZ and representatives of the Rescue Crew. We deplaned the passengers and crew and maintenance personnel took the airplane to perform a ground run up. Shortly after we deplaned; the [company operations manager] called me to let me know that [maintenance control] had noted that the aircraft had undergone an engine wash at ZZZ the night before our flight and that 3-4 times in the past few months; similar incidents had occurred. Maintenance found no further malfunctions in their ground run up. We re-manned the aircraft and flew without any subsequent problems.


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


Synopsis: A B737 flight reported rejecting the takeoff when they noticed smoke coming from air conditioning vents. The smoke was later traced to an engine wash that was done the previous night.