This bulletin supersedes the previously issued bulletin(s) listed below. The changes are noted in Red. 01-008/23 06/05/23 Some vehicles may exhibit rattling noises from the engine compartment and oil leakage from the drive belt auto tensioner. This may be caused by insufficient sealing at the drive belt auto tensioner damper when the auto tensioner fully operates under both high ambient temperature and high load conditions. To eliminate this concern, the shape of the drive belt auto tensioner damper has been changed. REPAIR PROCEDURE If the tensioner is found to be "No Good" after completing the Drive Belt Auto Tensioner Inspection, replace it with a modified part according to the instructio
full bulletin at NHTSA ↗2014 Mazda Mazda6 powertrain problems
severe Owners of the 2014 Mazda Mazda6 have filed 19 NHTSA complaints about the powertrain, typically surfacing around 45,000 miles at roughly $2,500 to repair (U.S. federal records, as of July 2026). Source: NHTSA Office of Defects Investigation. See powertrain across all vehicles →
Failure mileage
Complaints
19
Recalls
0
Avg fix
$2,500
| Model year | powertrain complaints |
|---|---|
| 2010 Mazda6 | 4 |
| 2014 Mazda6 (this page) | 19 |
| 2015 Mazda6 | 5 |
| 2016 Mazda6 | 9 |
| 2017 Mazda6 | 3 |
| 2018 Mazda6 | 7 |
2crashes
1injury
When does it fail?
Of the 19 powertrain complaints filed for the 2014 Mazda Mazda6, here's the actual mileage breakdown — failures cluster heaviest at 25,000-50,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
Among the 11 model years of Mazda Mazda6 in our records for powertrain problems, this one ranks #3 by owner-complaint volume.
No new NHTSA powertrain complaint has been filed on this vehicle in over 9 years — the issue may be aging out of the active population.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering powertrain on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
This Service Alert supersedes the previously issued SA listed below: The changes are noted in Red. SA-011/24 02/12/24, 06/06/24, 07/29/24 DESCRIPTION Mazda has developed factory recommended scheduled maintenance services that support all major vehicle systems. Mazda recommends dealers follow the scheduled maintenance tables as cited in the vehicle-specific workshop manual or owner's manual. Services performed outside of Mazda's factory scheduled maintenance are not recommended. These services are unnecessary and create unneeded expenses for your customers. SCHEDULED MAINTENANCE Refer to the applicable Workshop Manual or Owner's Manual for vehicle -specific manufacturer scheduled maintenance.
full bulletin at NHTSA ↗Noise, Vibration, and Harshness (NVH) Diagnostic Guidelines Diagnostic Guidelines When diagnosing NVH concerns, it is essential to first classify the issue into one of three primary categories: Noise, Vibration, or Harshness. Many customer complaints may involve overlapping symptoms, such as both noise and vibration, so identifying the dominant characteristic is critical. Once the primary symptom is determined, follow the appropriate diagnostic path. For example, if a concern includes both noise and vibration but is related to vehicle speed, the vibration diagnostic path should be followed. When considering component replacement during the diagnostic process, it is best practice to start wit
full bulletin at NHTSA ↗Some customer's might state that they notice fluid or oil leaking/dripping on the ground when the vehicle is parked. For this concern, inspect the vehicle for any trace of a fluid or oil leak and use the following examples as a guide to determine if it is severe enough to require a repair, or just to clean the area and monitor it at the next service. Examples of residue or seepage that may not be considered a leak and that may not require repair based on splash shield inspection.
full bulletin at NHTSA ↗The SKYACTIV-DRIVE FW6A-EL AT uses “Automatic Transmission Fluid (ATF) Type: FZ”. Only use “ATF-FZ” to fill or top off the fluid level. ATF-FZ is specially designed for use in the SKYACTIV-DRIVE series AT. It is a low viscosity formula with less friction for better fuel economy. NOTE: ATF-FZ is colored blue for easy identification.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Owners report three main clusters of failures in the 2014 Mazda6 powertrain. The first involves the start/stop ignition button failing to turn off the engine while parked. Owners describe the engine shutting down but the battery, radio, and instrument panel remaining energized; the car won't fully power off even in Park. Many report needing to shift the transmission in and out of Park multiple times or wiggle the gear shift before the engine finally kills. Dealers identified this as a faulty transmission shift switch, with costs ranging from $245–$400 for shifter assembly replacement. Mazda issued a technical service bulletin acknowledging the original shift-switch material lacked durability.
The second involves sudden unintended acceleration or engine revving while the vehicle is stopped at traffic lights or in traffic. The engine revs from idle to 4,000–6,000 RPM, causing the car to lurch forward and overcome the brake. One owner reported the transmission downshifting to unsafe RPM levels when pressing the steering-wheel phone button, happening repeatedly at highway speeds. Another incident involved sudden acceleration at 14,000 miles while pulling into a parking spot, resulting in a crash into a tree.
The third group reports transmission issues including high-pitched whining at highway speeds (linked to an incorrectly sized bearing), stuck gears, and delayed acceleration. One owner replaced a transmission at 70,000 miles for $7,000 out of warranty. Mazda identified a TSB for the bearing defect but does not cover out-of-warranty repairs.
Failure modes owners describe
Start/Stop ignition button fails to shut down ignition
Engine shuts off but ignition and auxiliary power remain active. Battery, radio, and instrument panel stay on. Vehicle displays 'shift lever to P' message despite being in Park. Requires multiple attempts shifting in and out of Park or wiggling gear shift to achieve full power-down.
When: Various mileages reported: 48,000 miles, unknown mileage, occurred intermittently over months or years
Symptoms owners cite: Engine turns off but ignition stays on; Radio and interior lights remain active; Battery drain over time; Repeated start/stop button presses needed; Shift lever shows not-in-Park error despite being in Park
Repairs/costs cited: Shifter assembly replacement: $245–$400 at dealer. Some owners replaced battery ($130) due to drain before addressing root cause.
Recalls/TSBs owners mention: TSB identified; Mazda replaced original shift-switch material with more durable version due to durability defect
Unintended acceleration while stopped
Engine revs to 4,000–6,000 RPM while vehicle is stationary in traffic or at red light, causing car to lurch forward and overcome brakes. Occurred 10–15 times over six months for one owner. Repeated pressing of steering-wheel phone button causes transmission downshift and unsafe RPM climb at highway speed.
When: Occurs when vehicle stopped in Drive with brake applied; one incident at low mileage (14,000 miles)
Symptoms owners cite: Engine revs from idle to 4,000–6,000 RPM without driver input; Vehicle lurches or accelerates forward; Brake unable to hold vehicle; Steering-wheel buttons trigger transmission downshift; Risk of crash
Repairs/costs cited: One case involved spiral cable replacement behind steering wheel. Most cases undiagnosed or unrepaired. Collision damage in one case ($5,000+ estimated).
Transmission bearing defect and transmission failure
Bearing of incorrect diameter installed in early 2014 models. Initial symptom is high-pitched whine at highway speeds. Transmission may stick in single gear, produce metallic clicking when shifting, or fail to engage Park correctly. Later symptoms include delayed acceleration and complete transmission failure.
When: Whining reported at highway speeds; one transmission failure at 70,000 miles
Symptoms owners cite: High-pitched whine at highway speeds; Metallic clicking when shifting into first or reverse from Park; Transmission stuck in single gear; Transmission does not recognize Park selection; Delayed acceleration at certain speeds; Check engine light
Repairs/costs cited: Full transmission replacement ~$5,000 (out-of-warranty cost); one repair billed $7,000 at dealer with ongoing clicking noise post-repair
Recalls/TSBs owners mention: TSB #05-005-15-3027A issued for bearing defect; Mazda offers replacement only within warranty; no commitment given on consequences of non-replacement
Transmission valve board failure
Valve board in transmission requires replacement, causing vehicle to decelerate unexpectedly while driving. Repair took extended time due to parts backorder. Ongoing acceleration delay persists post-repair with cause undetermined.
When: Unknown mileage; repair duration three weeks due to backorder
Symptoms owners cite: Vehicle decelerates without warning while driving; Delayed acceleration at certain speeds after repair; Check engine light or warning lights
Repairs/costs cited: Valve board replacement; dealer unable to resolve residual acceleration delay issue
Park gear not recognized by transmission control
Vehicle fails to recognize that transmission is in Park position. Ignition cannot be shut off even though shift lever is positioned in Park. Causes battery drain. Error message displayed on dash requesting shift to Park when already in Park.
When: 45,000 miles, other mileages unknown
Symptoms owners cite: Park position not recognized by vehicle; Ignition cannot shut off; Battery drain; Error message 'not in park' displays on dash
Repairs/costs cited: Independent mechanic could not diagnose or repair
Synthesized from 19 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 1 most recent
I was at a stoplight with my foot on the brake when the engine started to rev up, then I heard a thud and the car lurched forward and it felt like I was hit from behind. I pulled over to check for damage but nothing. This is a safety issue and there should be a recall as I see on the web others are having the same experience. The car is going to the Mazda dealer asap to see if they can correct…
Had powertrain trouble with your 2014 Mazda Mazda6?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the powertrain problem on the 2014 Mazda Mazda6?
It's a meaningful issue. 19 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $2,500.
At what mileage does the powertrain typically fail?
Across the 15 complaints that reported odometer mileage, most powertrain failures cluster between 25,000 and 50,000 miles, with the median around 45,000. A quarter of owners report trouble before 25,000; a quarter make it past 50,000. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
What does it cost to fix?
Independent shops typically charge around $2,500 for powertrain repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to powertrain?
No active recalls currently cover powertrain issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2014/Mazda/Mazda6.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.