What 49 owners told NHTSA about the 2021 Mazda Mazda3

My rear differential case cracked, anytime the four wheel drive system was engaged the entire drivetrain would lock up. Luckily we were only on side roads so going less than 30 mph if we had been on the highway when this happened we could have been in an accident or lost control. The dealer did confirm the problem and it was fixed under an extended warranty. There was no warning just all of a sudden a loud bang and all the wheels locked up. I have a copy of the video inspection done at the dealer if there's anyway to send that. I can get a copy of the repair invoice if needed

NHTSA ODI 11713224

At 31,000 miles the control arm lower ball joints are torn on both lower. They must be replaced. This is a safety hazard. This should not be an issue with low mileage on this car.

NHTSA ODI 11695896

I was driving when all the sudden there was a loud bang sound. The differential housing cracked. The when awd is demanded the rear diff was was locking up instead of engaging. Luckily we were just on city streets and not on the highway as this rear wheel locking up could cause a crash. Mazda wasn't very helpful with the replacement. Luckily I had a aftermarket warranty but it only paid for a used replacement, which is also failing. I have read lots of stories of this rear differential failure across all types of Mazda's from this era and really wish they would do the correct thing and resolve the problem.

NHTSA ODI 11663288

Spontaneous loss of power while driving on highway. Check engine light came on. Speed limited by car. Continues to vibrate especially at idle from cold start. Code P0304 intermittently popping up.

NHTSA ODI 11656416

During the incident, the vehicle exhibited an uncontrollable malfunction—the steering wheel suddenly jerked sharply to the right while accelerating violently, leaving me unable to steer or brake effectively, the car was looking forward. The car ultimately came to a stop upon colliding with a truck parked diagonally in front of me. After impact, I observed that the front tires remained stuck in a turned-right position, with the steering wheel also locked in that position. This was not an isolated event. Multiple reports from Mazda owners describe similar experiences with their vehicles unexpectedly veering to the right and accelerating without driver input. Given these recurring reports and my own experience, I strongly suspect that a manufacturing defect—whether mechanical, electronic, or software-related—may have contributed to this accident.

NHTSA ODI 11645615

The thermostat malfunctioned on this vehicle, resulting in the thermostat remaining open and providing excess coolant to the engine, which in turn damaged internal components of the engine (compromises safety), decreased fuel economy, increased emissions (compromised safety), and decreased the life of the engine within the vehicle. It is available for inspection upon request. The vehicle has been inspected by an independent mechanic and will be inspected by the Mazda dealership in 7 days. There were no prior warnings until the engine malfunction notice appeared, the vehicle began to make jolts and stuttering sounds, and the temperature gauge within the vehicle failed to rise to optimal range. As this occurred while the vehicle was in use (safety concern), though I was pushing the gas there would be delayed response due to improper temperature, which increased the risk for an accident to occur.

NHTSA ODI 11644041

When this feature is left on in my vehicle, it will detect curves, vehicles, and objects that are not there, and as a result, will attempt to turn my steering wheel (safety concern). I have had to keep this feature turned off to prevent it wrecking the car, because I could be on a straight road, and it will detect a curve that isn’t there and begin turning the wheel, which could result in a fatal accident if not corrected and disabled by the driver. It is available for inspection upon request. As the dealer has not driven the vehicle, they have not recreated the error, however if anyone were to drive the vehicle, they would be able to observe the malfunction. The dealer has been made aware on many occasions, though they never documented it and only suggested that I turn the feature off, which automatically turns itself on upon ignition. There are no warnings that there is a malfunction; you only know there is an error once an alert pops up thinking you’re missing a curve and attempts to turn your steering wheel though there is no curve. This issue has persisted over the life of the vehicle.

NHTSA ODI 11644042

The driver window, upon attempted to be let up, will start to go up then go all the way down, ignoring the function to go up. This is a safety concern, as harsh temperatures and foreign objects are able to enter the vehicle cabin at any time, including driving. The problem has been reproduced by a dealer, and the vehicle is available for inspection upon request. There are no warning indicators for this issue beyond witness the failure occur in real time.

NHTSA ODI 11644043

The contact owns a 2021 Mazda Mazda3. The contact received notification of an unknown Class Action Lawsuit Number however, the part to do the repair was unavailable. The contact stated that the manufacturer exceeded a reasonable amount of time for the repair. The manufacturer was made aware of the issue. The contact had not experienced a failure. Parts distribution disconnect.

NHTSA ODI 11631026

Radiators are failing 3 years after the warranty period. Its leading to coolant lost and perhaps overheating the engine.

NHTSA ODI 11627559

My 2021 Mazda 3 was bought used in August 2023 and is about a year old in my possession. it has been at the Mazda dealership for repairs multiple times since August 2023. it dangerously stalls and hesitates when trying to accelerate from a stop position. When the brake pedal is released and I start to accelerate like merging onto highways,the car rumbles or shakes slightly and then shuts off. I Came across a review online that had the exact same problem and it stated a PCM update solved the issue. I have been to the dealer frequently since purchased and they kept my car for over a week and claimed they could not reproduce the customers complaint and there is no diagnostic code generated. There is Frequent parking light malfunction alerts, switch operation not accepted alerts, Brake alerts on desolate roadways I believe this vehicle behavior is dangerous on multiple levels, but the dealer Refused to remedy the complaint or give me copies of the papers that I signed, stating they are only for the dealership. I also received a notice in the mail for a class action settlement for faulty fuel pump used in MAZDA vehicles but not the 2021 Mazda 3 although it displays the same Dangerous behavior. So between the faulty fuel pump or required PCM update the vehicle is questionable to drive safely under certain circumstances. The dealer inferred I should have purchased a used certified Mazda from them instead. Thanks

NHTSA ODI 11626518

Low oil light - car is burning oil and only has 11,400 miles. Approx 3/4 to 1 quart missing...

NHTSA ODI 11615747

At red light, close behind car in front of the mazda. After light turns green, start driving the mazda after car in front moves forward. Although the car in front is moving forward at a higher rate of speed, increasing the distance between it and the mazda, the automatic emergency brake kicks on and stops the vehicle abruptly. Luckily the cars behind the mazda reacted in time and did not rear end it.

NHTSA ODI 11613907

While driving at a normal speed on a clear, sunny day with no other vehicles close by, I heard a loud crash sound and my car's sunroof unexpectedly shattered. The inside glass panel looks like it's shattered and it caused tiny glass shards to fall inside the vehicle onto my right arm and the surrounding area. I closed the cover to prevent more from falling. This occurred without any prior warning, signs, or symptoms such as unusual noises or warning lights from the car. This incident posed a significant safety risk, not only due to the distraction, shock of the sudden noise, glass falling, injury in a potential accident, but also the potential for physical harm from the glass shards. Thankfully, no injuries occurred, but the potential for serious harm was evident. This problem has not yet been inspected by the dealer or confirmed by an independent service center, and there has been no opportunity for an inspection by any manufacturer, police, or insurance representatives. However, I've reached out to Mazda, both locally and corporate and am receiving a run-around, no surprise. I will attach photos of the inside and the outside of the glass. The outside photo was taken after the cover was closed. However, the broken sunroof is available for inspection upon request.

NHTSA ODI 11595814

Brakes are underpowered especially when hot. Drove 20-30 minutes in traffic and when decelerating from 60 mph highway in turn lane to turn into neighborhood the brakes felt very soft . Car only has 28k miles on it and pads have plenty of life left. Have seen similar complaints on online forums.

NHTSA ODI 11595331

Driving on a remote highway in northern WI and low oil light illuminated, 1000 miles before oil change was due with less than 10k miles on the vehicle. Made it to a gas station and oil was a quart low. Vehicle burns over a quart every oil change interval, since this has been occurring since day 1 it is likely going to cause premature engine failure which would be a safety issue.

NHTSA ODI 11595336

For the past 7 months (since July 2023) the passenger rear tire keeps loosing air pressure about every two weeks requiring more air. It always drops to 10 points below the other tires. The tires have been rotated twice so it is not a problem with the tire. I believe there is a recall for the same or similar issue on Mazda 3s just not including my VIN#. I brought my car to good year a few times unable to stop this from happening.

NHTSA ODI 11572875

A bolt head underneath the car snapped for the steering mechanism. The problem was indicated by a clanking noise I heard for many 1000s of miles. It's been as long as I remember, but I had no idea what it really meant. It's 2.7 years old with 30,653 miles right now. There were no warnings. The wheel could have come off at any moment I was driving it. The bolt was likely over-torqued or had a manufacturing defect causing it to snap. I have pictures for when the car was propped up at a technician. One side is completely non rusted. The other side is showing rust ONLY from where the bolt was covering, so rust is an unlikely cause.

NHTSA ODI 11572078

Part easily break away during washing. Fuel door cover lid panel (BDYT-42-411) broke in automatic car wash.

NHTSA ODI 11562777

Received Low Oil Level warning ... checked engine oil and it is under the minimum level on the dip stick. Car has only 11,725 miles

NHTSA ODI 11515727

Experiencing a known excessive oil consumption issue. Low engine oil warning light came on and upon checking, oil was low. This occured at 4000 to 4200 miles. It occured again about 4000 miles later and again at a similar interval. I notified the dealer and scheduled a repair date but I am concerned of other possible damage that may have already occured due to this issue. An oxygen sensor needs to be replaced and is most likely due to the engine malfunction. The cause of the consumption is said to be damage to the valve seals on the exhaust side.

NHTSA ODI 11515069

During a night drive, travelling approx. 40mph, car warning system audio blared a warning and suddenly braked causing car to skid (was raining) and causing driver to also jolt forward with momentum. There was very little time between beginning of audio warning and car slamming on brakes.

NHTSA ODI 11504587

The latches inside the driver's seatbelt receptacle feel like they wear out over time. The only reason I can tell is because there is a really noticeable creaking that develops from inside the receptacle while the seatbelt is connected. This is worse for drivers with bigger waists and as the driver's waist continues to tug on the seatbelt during operation, the creaking gets worse over time. There are no electronic warnings. The seatbelt still properly connects and there are no electronic messages saying that anything is wrong with the seatbelt. My driver's original seatbelt receptacle has already been replaced once under warranty at a Mazda dealership. Now the second seatbelt receptacle is starting to do the same thing again after about 6 months of use. I fear that even if I get it replaced a second time, this will just continue to happen. Perhaps there is a manufacturing defect. As this issue continues to get worse, I fear that this creaking will develop into a major failure with the seatbelt connection itself.

NHTSA ODI 11500412

Car emits a very audible squeak when shifting right above 30mph and 40mph, car surges at lower and constant speeds, tach will slowly drop when applying throttle, surge slightly, then function as normal again

NHTSA ODI 11499817

Purchased car in January 2020 and within a month/few thousand miles the low engine oil light came on. Almost two years later car continues to burn excessive oil triggering low engine oil light. Dealer doesn’t acknowledge an issue, Mazda still doesn’t have a repair. Owners required to pay for excess servicing until a repair is issued. This is a widespread problem impacting the engine.

NHTSA ODI 11493335