2018 Mazda MAZDA6

58 complaints on file, page 1 of 3.

1. Filed Aug 29, 2026Failure May 16, 2026Spring Hope, NCOther/i am not sure, Tether, Lower anchor (on car seat or vehicle)

   Have had 3 seats replaced under warranty by Graco and was told to make a report with you. The rigid latch anchors on two have been faulty after 2 months. The second one got stuck in the installed base and pulling the release button did nothing. The rigid latch on the first got stuck in the open position. The second they would move independently of each other and not lock in. The third is starting to have the same issue with getting stuck in the base. These have all happened within two months of normal use.

   NHTSA complaint 11760546
2. Filed Aug 28, 2026Failure Aug 28, 2026Jacksonville, FLFuel/propulsion system, Wheels

   Fuel pump is leaking, just as all the other 2018-2020 fuel pumps but mine doesn’t qualify for the recall.

   NHTSA complaint 11760260
3. Filed Aug 7, 2026Failure Aug 7, 2026Madison, VAEngine

   The car only has 70k miles on it. The engine started smoking under the hood. Immediately stopped to look. There was oil leaking but I could not see from where. I took it across the street to the Toyota dealership and had them look at it. They explained to me that there was a crack in the cylinder head and oil was leaking everywhere. Potentially causing a fire or even an explosion. The old was leaking all over the exhaust manifold and engine. I had my 2 toddlers in the car not long before this happened. This is extremely unacceptable. Currently Mazda is saying it will be 7200 to replace the engine and that cost is on me. I think that is absolutely absurd being there are only 70k miles on the car and I bought it brand new. I also kept up with all of the required maintenance.

   NHTSA complaint 11755535
4. Filed Jul 29, 2026Failure Jul 29, 2026Arnold, MDSteering, Suspension, Vehicle speed control

   Got error message that said "Forward Smart City Brake Support Malfunction" slso fot "smart brake malfunction" while driving. The ac stopped, the car speedometer kept going from 50 to zero. The car died and couldn't open doors, windows. Lost steering while driving. We were able to get off road and restart and fine for 2 weeks. While at still light tonight, the car turned off. Windows were up, couldn't open door, emergency blinkers would not come on. This is very dangerous.

   NHTSA complaint 11753644
5. Filed Apr 30, 2026Failure Apr 25, 2026Pittsburg, CAEngine

   Crack in Cylinder Head of engine. Mazda has been sued about this and have issued recalls on turbo engines, but not on non turbo ones though its the same systemic design issue with these engines. Wants me to pay 5-7k out of pocket.

   NHTSA complaint 11734993
6. Filed Apr 22, 2026Failure Jun 1, 2025Lakewood, NJEngine

   My cylinder head is leaking coolant. There is a well known and well documented issue with these cylinder heads cracking due to poor casting. This has become such a big issue that Mazda has even recalled the cylinder heads, BUT, only if the engine is equipped with Turbo. However, this issue is becoming enormous even for non turbo owners and is a huge safety issue as it can lead to overheating, stalling, and further damage to other components. I feel very strongly that it is time for Mazda to take some responsibility and extend the cylinder head recall to the non turbo engines.

   NHTSA complaint 11733118
7. Filed Apr 7, 2026Failure Apr 4, 2026Fountain Valley, CAEngine

   Car had a coolant leak due to cracked cylinder head that was defective from the factory it was fixed but now the car has engine problems again. Don’t want to keep having these issues in the future

   NHTSA complaint 11729758
8. Filed Apr 1, 2026Failure Mar 2, 2026Plainfield, ILPower train

   System Failure: The Power Train (6-speed Automatic Transmission) suffered a major malfunction, documented by diagnostic codes P0731 (Gear 1 Incorrect Ratio) and P0780 (Shift Error). The vehicle is available for inspection. Safety Risk: The failure caused a sudden loss of propulsion while attempting to accelerate. This created an immediate risk of a rear-end collision and left the vehicle unresponsive in the path of oncoming traffic. The transmission's unpredictable shifting makes the vehicle unsafe to operate. Confirmation: The failure and the P0731 code were officially confirmed by Castle Mazda on March 2, 2026. The manufacturer (Mazda) has been notified but has denied a remedy, despite TSB MC-10160555-0001 addressing this specific internal defect. Warning Symptoms: There was no Check Engine Light or dashboard warning prior to or during the failure. The only warning was an extreme, abnormal mechanical grinding/clunking noise from the transmission. The lack of a malfunction indicator light (MIL) meant I had no electronic warning of a looming mechanical failure while in motion.

   NHTSA complaint 11728615
9. Filed Feb 22, 2026Failure Feb 13, 2026Exton, PAEngine

   Per Mazda inspection, the back side of cylinder head #3 has an oil leak which is leaking onto the exhaust manifold. This creates a direct fire hazard as Mazda said they highly recommend not driving it for that reason. The Mazda dealership inspected and confirmed the issue, it in February 2026, with only 74,000 miles on the vehicle.

   NHTSA complaint 11719756
10. Filed Jan 7, 2026Failure Dec 23, 2025North Charleston, SCEngine, Power train

    I recently discovered a significant oil leak near the exhaust manifold of my 2018 Mazda 6 (2.5L NA), which has resulted in visible smoke and a burning oil odor. Upon taking the vehicle to the nearest Mazda dealership for a diagnosis, the service department informed me that the vehicle has suffered a cracked cylinder head. An active oil drip is visible behind the engine near the exhaust manifold immediately upon starting the car; consequently, the engine is leaking oil directly onto the exhaust components. This condition not only renders the vehicle inoperable but also presents a significant safety and fire hazard. At the time of this writing, my vehicle has only 46,996 miles and has been meticulously maintained. This mileage is well under the 60,000-mile powertrain threshold and represents a premature failure of a major internal engine component. There are numerous reports on Mazda owner forums describing this identical issue occurring in Mazda 6, CX-5, and CX-9 models. Some owners have even reported instances of minor fires or active burning under the hood due to oil contacting hot engine components. Mazda released Technical Service Bulletin TSB #MC-10241612-0001 (SA-037-23), which includes a redesigned cylinder head for 2018–2020 Mazda 6, 2019 CX-5, and 2016–2020 CX-9 models, demonstrating Mazda’s awareness of this design flaw. While the TSB currently only specifies the 2.5L Turbo engines and not the naturally aspirated variants, there is substantial evidence that this is a widespread defect across these model years, unrelated to owner misuse or vehicle mileage. Mazda should take full responsibility by issuing a formal recall or providing an extended warranty to cover naturally aspirated engines, thereby addressing this problem and preventing further safety risks.

    NHTSA complaint 11709431
11. Filed Oct 17, 2025Failure Oct 11, 2025Ontario, OHEngine

    Cracked cylinder head causing oil leak and possible coolant leak. This is a known issue with this year and model. Mazda is trying to suggest the issue is only for the turbo engine, but the non-turbo engine is also defective, per countless reports online. I have a video from the service technician from the mazda dealership, but it is too big to upload.

    NHTSA complaint 11694210
12. Filed Sep 18, 2025Failure Jul 25, 2025Fresno, CAPower train

    Was driving then car suddenly shut down and all panel lights turned on. The car would not start after an hour it started but was Perkins when driving. Mechanics were unable to diagnose the issue.

    NHTSA complaint 11688263
13. Filed May 27, 2025Failure May 6, 2024Oregon City, ORService brakes

    Premature caliper failure on front and rear. Ruined rotors at 40k miles, confirmed caliper failure by two service shops. Grinding/squeaking sounds intermittently been happening for since 30,000 miles

    NHTSA complaint 11663276
14. Filed May 14, 2025Failure Mar 26, 202575,000 milesProvincetown, MAFuel system, Fuel pump

    The contact owns a 2018 Mazda Mazda6. The contact stated upon taken the vehicle to the dealer for an oil change, the dealer notified the contact of a fuel leak. The dealer diagnosed the vehicle and informed the contact that the top of the fuel tank and bolts connected to the fuel pump were significantly rusted, causing the fuel leak. The dealer determined that the fuel tank and the fuel pump needed to be replaced. The vehicle was repaired. The manufacturer was notified of the failure and informed the contact that no assistance would be provided because the contact had already authorized the dealer to repair the vehicle. The failure mileage was approximately 75,000.

    NHTSA complaint 11660947
15. Filed May 9, 2025Failure Apr 18, 2025Snellville, GAEngine

    Bought used with 47k miles. Two weeks later, took it to my mechanic for an inspection, they found a massive oil leak on the back of the motor. Took it back to the dealership and they diagnosed it as a cracked cylinder head, for which there is a known TSB and warranty extension. Unfortunately, the warranty extension only covers a coolant leak from the cracked cylinder head, not an oil leak. Thankfully, the dealership took care of me but had they not, I was looking at a $7k+ repair on a car I had owned for 2 weeks. In the TSB, Mazda acknowledges that there were both design and manufacturing flaws for the affected model years. In acknowledging the issue, they should have issued a recall for affected vehicles, not a simple warranty extension

    NHTSA complaint 11659983
16. Filed Mar 6, 2025Failure Mar 5, 2025Cary, NCService brakes

    I am having my brake pads changed at a local mechanic and when changing the pads, the mechanic was unable to change them because the rotors and calipers were rusted and the brake pistons stuck. The previous recall only considered Mazda 6 up to 2013 but my 2018 has had the same problem.

    NHTSA complaint 11646848
17. Filed Jan 17, 2025Failure Jan 14, 2025Rocklin, CAUnknown or other

    Software error/loss of engine power. No warning of this before it happens. The car completely loses power, and stalls or stops in the middle of me driving. This has happened on the freeway and risked my life as well as my husbands, and children. This same issue has been a previous recall and fixed in 2019 for my car, and now it is happening again.

    NHTSA complaint 11636672
18. Filed Jan 8, 2025Failure Dec 10, 2023Benton, KYEngine, Unknown or other

    Coolant leaks at the cylinder head around the exhaust manifold causing my car to over heat. Also when my thermostat is set to the exact temperature for both sides my driver side blows cold and the passenger side blows hot

    NHTSA complaint 11634788
19. Filed Jan 4, 2025Failure Dec 22, 2024Lafayette, NJEngine

    Driving in traffic and the engine temperature warning appeared on dash. Dealer has confirmed there is a large coolant leak from the cylinder head. Mazda released a technical service bulletin regarding the issue affecting Mazda6, cx-5 and cx-9, but I will have to pay for a head gasket replacement.

    NHTSA complaint 11634029
20. Filed Nov 26, 2024Failure Nov 18, 2024Harvey Cedars, NJEngine

    Cracked cylinder head near the exhaust manifold. Created a large oil leak. Oil on the exhaust is a fire hazard. After one quart of oil loss a low oil level light comes on. This is a reported problem. One version of the engine I have has a Mazda TSB and an extended warranty. TSB 01-0022/23 A local repair shop has diagnosed the problem.

    NHTSA complaint 11627463