PulsCar analysis of NHTSA public data, September 2026 — car making a humming noise
Article: https://www.pulscar.io/blog/car-making-humming-noise
License: CC BY 4.0. Credit "PulsCar analysis of NHTSA public data" with a link to the article.

SOURCE FILES
- Complaints: https://static.nhtsa.gov/odi/ffdd/cmpl/ — COMPLAINTS_RECEIVED_2015-2019.zip, COMPLAINTS_RECEIVED_2020-2024.zip,
  COMPLAINTS_RECEIVED_2025-2026.zip. Unit = one ODINO, PROD_TYPE V. Received dates (LDATE) 2015-01-01 to 2026-09-08. 777,040 complaints.
  Fields used: MAKETXT, MODELTXT, YEARTXT, LDATE, MILES, CRASH, FIRE, TOWED, VSPEED, COMPDESC, CDESCR.
- Recalls: https://static.nhtsa.gov/odi/ffdd/rcl/ FLAT_RCL, report dates 2015-01-01 to 2026-09-09; one row per make/model/year per campaign.
- Manufacturer communications: https://static.nhtsa.gov/odi/ffdd/tsbs/ — received 2015-01-06 to 2026-09-12, 187,827 distinct NHTSA IDs.
- Investigations: https://static.nhtsa.gov/odi/ffdd/inv/ FLAT_INV.

FILES: hum_complaints_summary.csv, hum_complaints_by_words.csv, hum_complaints_by_nhtsa_component.csv, hum_complaints_by_speed.csv,
       hum_complaints_by_model.csv, hum_complaints_by_make.csv, hum_complaints_reported_repairs.csv
 Candidate texts: FTS5 query hum OR hums OR humming OR hummed on CDESCR (830), kept if the text matches \bhum(s|ming|med)?\b and the
 only match is not an idiom (humming along | ho-hum | humdrum | hum of traffic/the road): 829.
 System word groups (Python re, case-insensitive) on CDESCR; a complaint can fall in several:
  wheel bearing or hub = wheel bearing|hub bearing|hub assembl|\bhub\b|bearing
  tires = \btires?\b|tread|cupp
  differential, axle, transfer case, PTU or driveshaft = differential|\baxle|transfer case|\bptu\b|power transfer unit|drive ?shaft|propshaft|cv joint|cv axle
  transmission, CVT or torque converter = transmission|\bcvt\b|torque converter|transaxle
  brakes = \bbrake|caliper|rotor ; power steering = power steering|steering pump|\beps\b ; fuel pump = fuel pump
  EV or hybrid = inverter|drive unit|electric motor|hybrid battery|high.voltage|traction battery|\bev\b
  engine, timing chain or accessories = \bengine\b|timing chain|alternator|belt|pulley|tensioner|water pump|\bidler
  exhaust = exhaust|muffler|catalytic|resonator ; HVAC = blower|\bhvac\b|\ba/?c\b|air condition|radiator fan|cooling fan
  wind or body = \bwind\b|sunroof|mirror|roof rack|door seal|weather ?strip
 Note: "bearing" alone also matches engine rod bearings and the word in "wheel bearing"; the group is therefore a ceiling for wheel bearings.
 NHTSA component = first segment of each COMPDESC entry (before the colon), counted once per complaint.
 Speed = VSPEED 1-149 (445 complaints). Mileage = MILES 0 < x < 400,000 (506). Age = LDATE year minus YEARTXT, 0-30.
 Baselines (all 777,040): towed 5.1%, crash 4.4%, fire 1.8%.
 could not find = phrase list: could(n't|not)/unable to/failed to/did not (duplicate|replicate|reproduce|find ...|locate ...|hear ...|verify|
 figure out|determine); no (problem|trouble|issue|fault)s? found; nothing (found|wrong); could not be (duplicated|...); operating as designed;
 normal (operation|characteristic); is/are/was normal (54).
 turning = \bturn(s|ing|ed)?\b|steer|curve|lane change|cornering (240). no light/code = no (trouble|fault|error|diagnostic|check engine|warning)?
 (codes?|lights?) and variants (69). dealer = "dealer" anywhere (376).
 Reported repairs = (replac|new|chang|rebuil)… within 30-40 characters of the part word, or the part word followed by replaced/rebuilt/rotated;
 undercounts because most complaints are filed before repair. Software = software|reprogram|reflash|update the (computer|module|tcm|pcm).
 By model: 25 models with the most hum complaints; per_1000 uses all complaints for that make+model 2015-2026. By make: top 20.
 Hand reading of 40 random hum complaints: 40/40 mention a humming noise; 22 describe a road-speed hum from a wheel, tire or driveline;
 10 an engine-bay or electrical hum (alternator, start-up, hybrid parked); 8 other (dash/ABS, braking, fuel-tank strap, unknown).

FILE: wheel_hub_bearing_recalls_2015_2026.csv
 Campaigns reported 2015-01-01 to 2026-09-09 whose COMPNAME contains HUB or whose DEFECT text contains "wheel bearing", "hub bearing",
 "wheel hub" or "bearing", then kept if the defect text contains bearing/hub AND wheel/hub (150 campaigns, 442,533 vehicles = max POTAFF per
 campaign). passenger_or_light_truck_wheel_bearing_or_hub = Y was assigned by hand (21 campaigns, 175,222 vehicles) after reading each
 defect text; trailers, wheelchair-lift conversions, motorcycles, scooters, heavy trucks, steering-column bearings and generic service parts
 are N. Two records (24V102000, 24V794000) were re-read through https://api.nhtsa.gov/recalls/campaignNumber.

FILES: hum_bulletins.csv, hum_bulletins_by_system.csv, hum_bulletins_by_make.csv
 FTS5 query hum OR hums OR humming OR hummed on the SUMMARY field, kept if \bhum(s|ming|med)?\b matches (280 distinct NHTSA IDs), minus
 28 documents from VERIZON about the "Hum" telematics device (252). System regexes on SUMMARY (a document can fall in several):
  wheel bearing or hub = wheel bearing|hub bearing|hub assembl|wheel hub|hub/bearing ; tires = \btires?\b|tread
  differential… = differential|\baxle|transfer case|\bptu\b|power transfer unit|drive ?shaft|propshaft|half ?shaft|driveline
  transmission… = transmission|\bcvt\b|torque converter|transaxle ; brakes = \bbrake|caliper|rotor
  power steering = power steering|steering (pump|gear|rack)|\beps\b|steering ; fuel pump = fuel pump
  EV/hybrid = inverter|drive unit|electric motor|hybrid|high.voltage|traction motor|\bev\b|charger|motor generator|\bmgr\b
  engine… = \bengine\b|timing chain|alternator|belt|pulley|tensioner|water pump|\bidler|generator ; exhaust = exhaust|muffler|catalytic|resonator
  HVAC… = blower|\bhvac\b|\ba/?c\b|air condition|radiator fan|cooling fan|compressor|heater
  audio… = speaker|audio|radio|amplifier|antenna|\banc\b|noise cancel ; wind/body… = \bwind\b|sunroof|mirror|roof|door|seal|weather ?strip|trim|panel
  software = software|reprogram|reflash|calibrat|update (27).
 30 random summaries were read: 27 described a vehicle noise, 3 were Verizon device notices (removed from all counts).
 Bulletin PDFs on static.nhtsa.gov could not be opened (URL suffix not published); quotations are from the summaries in the flat file.

FILE (not published): investigations — 50 actions whose subject or component names bearing / wheel hub; all but DP12001 (BMW motorcycle final
 drive, 2012-2013) predate 1990.

LIMITATIONS
 Complaints are self-reported, unverified, and skewed toward safety outcomes and unresolved problems; they do not measure how often a hum is a
 bearing versus a tire in the repair market. Counts by make and model follow sales and complaint habits. The previous edition's "45% bearing /
 35% tire" split could not be sourced and is not used.

OUTSIDE SOURCES OPENED 18 SEPTEMBER 2026
 NHTSA recalls API records 24V102000, 24V794000; 49 U.S.C. 30120 (Cornell LII); AAA 2026 labor-rate article. Refused (403/404): Timken, SKF,
 Tire Rack, static.nhtsa.gov bulletin PDFs.