2018 Mazda Mazda6 Problems

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.

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.

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.

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.

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

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.

Was at a drive in window and car turned off and couldn't restart. Windows and lights would work but car wouldn't restart. Could of been driving and would of crashed. Had 3 people family in car. It was 9 pm had to have towed to nearest auto mechanic place 150.00. They are diagnosing and that is 186.00. This is a scary thing and going to BBB and filing a complaint I'm mad as he'll. Have had inspection done on this car 2 months ago and all required services to this car. This was without warning which is horrifying.

The contact owns a 2018 Mazda Mazda6. The contact stated that he had experienced a transmission surged on five separate occasions since owning the vehicle. There were no warning lights illuminated. The contact had taken the vehicle to the dealer after each failure and various unknown repairs and software updates were performed on the vehicle. However, the failure persisted after each visit. The manufacturer was notified of the failure and a case was opened. The vehicle was not repaired. The failure mileage was approximately 10,000.

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.

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

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

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.

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.

THE FRONT AND REAR SUSPENSION POPS, CLUNKS, THE VEHICLE SHAKES, VIBRATION ALSO HAPPENS, IT ALSO CAUSING TIRES TO BE REPLACED FASTER THAN NORMAL THEY GO BOLD IN THE CENTER ITS CAUSING NOW THE AXLES TO SHAKE AT NIGHT TIME YOU CAN SEE THE REFLECTION FROM HEADLIGHTS BOUNCING, THEY HAVE TSB'S ON THIS SUSPENSION ISSUE HOWEVER NOT FOR 2018 ONLY 14-16 MAZDA 6S I BELIEVE AND SUPPOSEDLY THE ISSUE WAS CORRECTED WELL THEY LIED BECAUSE MINE IS A 18 AND IT IS A DISASTER, MY TRANSMISSION IS NOW SHIFTING VERY HARD FROM 1ST TO SECOND GEAR, TURN WHEEL IT MAKES A LOUD CLUNK SOUND OR POPPING SOUND, GO OVER A DIP IN ROAD DOES THE SAME THING, YOU GO OVER A BUMP THE VEHICLE FEELS SOGGY, IT LIKE DRIBBLES, IT CAUSES THE VEHICLE TO SWAY.. IT'S HORRIBLE, ALSO THE BRAKES WAS SHAKING AT 15K MILES, FOUND OUT IT'S TSBS ON THIS ISSUE AND OF COURSE THE DEALERSHIP DIDN'T FIX FOR FREE, CHARGED ME OVER 600 DOLLARS FOR A ISSUE THAT HAS A TSB ON.

After only 3 years and less than 17,000 miles of driving, the soul red crystal metallic paint is chipping in many spots on the front of the body. There are at least 100 small chips on the hood, bumper, and front fenders. All of this occurred under normal driving conditions.

AFTER LESS THAN A YEAR OF LEASING THIS VEHICLE, AN ABUNDANCE OF ROCK CHIPS HAVE SHOWN UP, MORE THAN ANY OTHER CAR I'VE LEASED. THIS PAINT SEEMS EXTREMELY SUSCEPTIBLE TO FOREIGN OBJECTS. (THIS WOULD BE THE SOUL RED COLOR THEY USE.) ITEMS THAT SHOULDN'T CAUSE A SCRATCH DO, AND ROAD DEBRIS CAUSES CHIPS THAT SHOULDN'T FAR TOO MUCH.

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.

When I put my car on reverse the sensors beep continuously and give the impression that there are obstacles behind your car. I cleaned all the sensors, but noise is still there. I see a lot of posts regarding same issue.

THE DRIVER SIDE MIRROR VIBRATES AT HIGHWAY SPEEDS MAKING IT EXTREMELY HARD TO SEE WHAT'S IN THE GLASS.

WHILE MERGING ONTO THE FREEWAY ON MY WAY HOME FROM WORK, THE SUNROOF EXPLODED. I WAS DRIVING STRAIGHT ON THE FREEWAY WITH LIGHT TRAFFIC AT APPROXIMATELY 70 MPH. I DID NOT SEE ANY DEBRIS OR ROCKS AND AFTER STOPPING DID NOT FIND ANY DEBRIS OR SIGNS OF ANYTHING HAVING HIT THE GLASS. THERE WAS JUST A LOUD NOISE LIKE THE SOUND OF A SHOTGUN BLAST AND THE MAJORITY OF THE CENTER OF THE SUNROOF WAS GONE. I REPORTED THE ISSUE TO MAZDA AND THEY SAID THAT IT WAS DUE TO "ENVIRONMENTAL FACTORS" AND WAS NOT COVERED BY THEIR WARRANTY. THEY TOLD ME THAT THE REPLACEMENT GLASS WOULD BE $302 WITH APPROXIMATELY $450 IN LABOR BECAUSE THEY WOULD HAVE TO REMOVE THE HEADLINER AND VACUUM OUT ANY GLASS.

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.

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.

TL* THE CONTACT OWNS A 2018 MAZDA 6. WHILE THE CONTACT'S FRIEND WAS DRIVING 55 MPH, HE VEERED OFF THE SIDE OF THE ROAD INTO A DIRT PATCH, AND STRUCK AN OBJECT. THE AIR BAGS DEPLOYED AND THE DRIVER'S SEAT BELT UNBUCKLED UPON IMPACT. THE AIR BAG DEPLOYMENT BURNED THE CONTACT'S RIGHT UNDERARM. MEDICAL ATTENTION WAS NOT RECEIVED. A POLICE REPORT WAS NOT FILED. THE CONTACT'S FRIEND WAS ABLE TO DRIVE THE VEHICLE BACK TO HIS APARTMENT. THE VEHICLE WAS NOT DIAGNOSED OR REPAIRED. THE MANUFACTURER WAS NOTIFIED OF THE FAILURE AND DID NOT ASSIST. THE DEALER WAS NOT CONTACTED. THE FAILURE MILEAGE WAS APPROXIMATELY 18,000. *DT CONSUMER STATED PARTIAL RETRACT DUE TO PRETENSIONER FIRING. CANNOT BUCKLE ' 8 IN TOO SHORT. BOTH HANDS ON STEERING WHEEL. WEIRD SEAT BELT UNLATCHED.*JB