2021 Mazda Mazda3 Problems

What to check before you buy

• Ask the seller not to warm the car up, and start it cold. Listen for ticking, knocking or a rough idle in the first minute.
• Pull the oil dipstick and the oil cap. Low oil, a gasoline smell or a milky film on the cap are reasons to walk away or get an inspection.
• Plug in an OBD2 scanner. Stored or pending codes matter, and so do readiness monitors that show "not ready", which usually means the codes were cleared right before the sale.
• Ask for oil change records. A gap in the records on a model known for engine complaints is a negotiating point at minimum.

Tools that help

What owners said

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.Owner complaint, filed 2025

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…Owner complaint, filed 2025

What to check before you buy

• Where it is safe, try the adaptive cruise and lane keeping on the test drive and watch for sudden braking or warnings with nothing there.
• Check the windshield in front of the camera and the bumper sensors for cracks, chips or poor repairs.
• Ask whether the windshield has been replaced. The camera has to be recalibrated afterward, and many shops skip it.

Tools that help

What owners said

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…Owner complaint, filed 2025

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…Owner complaint, filed 2024

What to check before you buy

• Test every switch: windows, locks, mirrors, seat heaters, the screen, the backup camera, Bluetooth and every USB port.
• Watch the dash at startup. Every warning light should come on briefly and then go out.
• Have the battery and charging system tested. A weak alternator or battery drain shows up here.

Tools that help

What owners said

While driving to work, the dashboard displayed “Charging system malfunction, pull over.” The driver pulled over safely. The vehicle has electric power steering, so a loss of charging power while driving could reduce steering assist and cause the vehicle to stall in traffic. This happened three days after a Mazda dealer replaced the front…Owner complaint, filed 2026

The contact owns a 2021 Mazda Mazda3. The contact stated that while driving at various speeds the passenger front side tire was flat which caused the contact to veer to the shoulder. The contact towed the vehicle to the dealer where the tire was inspected as the technician informed the contact that the tire was on backorder and no…Owner complaint, filed 2021, at 2,509 miles

What to check before you buy

• The pedal should feel firm and the car should stop straight without pulling, grinding or a pulsing pedal.
• The ABS and stability control lights should go out after startup and stay out.
• Look through the wheels at the rotors. A deep lip on the edge means brakes are due soon, which is a fair thing to negotiate on.

Tools that help

What owners said

Car made grinding sound with notable vibration when starting to move after shifting into drive. Felt like brakes weren't releasing. Had car towed to dealership where they diagnosed that the front left brake shim was damaged and making contact with the rotor, had to pay to fix it out of pocket.Owner complaint, filed 2026, at 45,946 miles

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.Owner complaint, filed 2024

What to check before you buy

• Drive it from cold if you can. Shifts should be smooth in every gear, including reverse.
• Feel for slipping (revs rise without the car speeding up), shudder at low speed and a delay when you put it in gear.
• Listen for whining, which is a common CVT complaint, and clunks when you go from drive to reverse.
• If it has 4WD or AWD, engage it on the test drive and ask when the transmission and differential fluids were last changed.

Tools that help

What owners said

Making sharp right turn out of parking lot under hard acceleration, car suddenly made terrible grinding sound that shook the whole car. Continued driving, within another quarter mile the whole car started shaking again with loud noise. Had car towed to Mazda where they discovered that the rear differential had failed. Rear differential…Owner complaint, filed 2026

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…Owner complaint, filed 2026

What to check before you buy

• The air bag (SRS) light should come on at startup and go out within a few seconds. If it stays on, the system may not work in a crash.
• Air bag recalls are some of the most serious. Check this exact VIN for open recalls and get proof any recall work was done.

Tools that help

What owners said

The vehicle was badly rear ended and the airbags didn't deploy. The dashboard indicated an "airbag malfunction" after the collision happened. The failure of the airbags put myself and my passengers at serious risk; if we weren't wearing our seatbelts, which we were, we would have been gravely injured. The vehicle is less than a year old…Owner complaint, filed 2022

My car started to show a warning on the dashboard that the airbag system is malfunctioning. The alarm would come on for a few seconds, then turn off, then repeat like that multiple times every drive. At the time it started, my car had less than 500 miles on it, and it continued after that until I got it fixed. I took it to the Mazda…Owner complaint, filed 2022

What to check before you buy

• Smell around the engine bay and under the rear of the car for raw fuel.
• On the test drive, accelerate firmly from a stop and up a grade. Stumbling, surging or a flashing check engine light are red flags.
• Fuel pump recalls are common. Check this exact VIN for open recalls before you buy.

Tools that help

What owners said

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 againOwner complaint, filed 2023

Strong unburnt fuel smell had just started at 6700 miles. Mazda Dealership stated that they would not be looking at my car and that gas smells are normal... After this encounter, I had 2 mechanics look at my car. Both had concluded that the smell predominantly comes from near the rear driver wheel, under the body, and that it is an…Owner complaint, filed 2022

What to check before you buy

• Drive over a few bumps and potholes slowly with the radio off and listen for clunks or rattles.
• Check the tires for uneven wear on the inside or outside edges, a sign of alignment or suspension trouble.
• Look behind the wheels for oily, wet shocks or struts.

Tools that help

What owners said

Vehicle: 2021 Mazda Mazda3 VIN: [XXX] Mileage at failure: 111,777 Date the problem started: [date you first heard the clunk] Location: [town], [XXX] Crash / fire / injury / death: No Was the vehicle moving? Yes Component: Suspension: Front (Lower Control Arm) Description: The front passenger-side lower control arm on my 2021 Mazda3…Owner complaint, filed 2026

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.Owner complaint, filed 2025

What to check before you buy

• On the test drive, press the gas gently and firmly. The response should be smooth with no lag or surge.
• Set the cruise control, then use resume and cancel to make sure each one works.

Tools that help

What owners said

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…Owner complaint, filed 2025

Context: ADAS was not on. Lane keep assist is disabled in system settings entirely as it is dangerous. Blinkers were on, I was pulling out from parallel parking into left turn lane onto a straight road with slight incline. Car is of the Turbo trim on stock tires. Upon finishing pulling out of parallel parking spot and gassing the car…Owner complaint, filed 2022

What to check before you buy

• Look underneath with a flashlight. Utah road salt is hard on frames, brake lines and the bottoms of doors.
• Open and close every door, the hood and the liftgate, and lock and unlock each one.
• Use a paint thickness gauge and compare panels. A panel that reads very differently from the rest has likely been repaired.

Tools that help

What owners said

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…Owner complaint, filed 2024

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 againOwner complaint, filed 2023

What to check before you buy

• Read the four-digit DOT date on each tire. Tires older than about six years should be replaced, whatever the tread looks like.
• Check tread depth on all four. On AWD vehicles all four tires should match.
• The tire pressure light should go out after startup.

Tools that help

What owners said

This new car has less than 8000 miles on it and suddenly 3 of 4 BRIDGESTONE TIRES Turanza el440 215/45R18 89 have sidewall bubbles. Interesting that there are a ton of issues w sidewall Bridgestone tires on line yet the dealership keeps claiming the car must have been run over a median? Without any damage anywhere on the car? Come on..…Owner complaint, filed 2022

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…Owner complaint, filed 2024

What to check before you buy

• Turn the wheel lock to lock while parked and listen for groaning, clicking or binding.
• On a straight road the car should track straight with the wheel centered and no loose feeling.
• A power steering warning on the dash, even briefly, deserves a mechanic’s look before you buy.

Tools that help

What owners said

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…Owner complaint, filed 2025

What to check before you buy

• Pull out and latch every seat belt, and let each one retract on its own.
• Try every seat adjuster, and watch for a passenger air bag "off" light when an adult is in the seat.

Tools that help

What owners said

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…Owner complaint, filed 2023