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.
2021 Mazda MAZDA3
Owner reports · Recalls · Investigations
Fewer warning signs than most model years
Owner complaints for the 2021 Mazda MAZDA3 are lower than the model-year median of 108.
About this comparison →How this year compares
Owner complaints by model year
Compare all MAZDA3 years →Counts vary with age, sales and reporting. They are not failure rates.
What owners reported most
All reported categories
Tap a category to read its complaints. One report may name several components.
When problems were reported
Mileage at the reported incident
Limited mileage data: 3 of 49 reports include usable mileage. There isn’t enough coverage to show a useful chart.
NHTSA’s mileage field refers to the reported incident, not necessarily the filing date. This shows report counts, not the likelihood of a failure.
What to inspect
Issues worth paying extra attention to based on owner reports.
- Engine. Review the 18 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
- Forward Collision Avoidance. Review the 7 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
- Electrical System. Review the 6 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
NHTSA owner reports · September 18, 2026 snapshot.
Engine complaints
18 reportsThe 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 vehic…
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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.
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 expe…
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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.
Low oil light - car is burning oil and only has 11,400 miles. Approx 3/4 to 1 quart missing...
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 pr…
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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.
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
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…
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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.
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
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 is…
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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.
Turbo using/burning oil- Consumption issue.
Official recalls
121V101000 · Tires:valve
Feb 22, 2021
Mazda North American Operations (Mazda) is recalling certain 2021 Mazda3 and CX-30 vehicles. Air may suddenly leak from the tire air valve.
Consequence & remedy
Consequence: A sudden air leak from the tire air valve may cause a loss of vehicle control while driving, increasing the risk of a crash.
Remedy: Mazda will notify owners, and dealers will replace all four tire air valves with new parts, free of charge. The recall began April 6, 2021. Owners may contact Mazda customer service at 1-800-222-5500 Option 4. Mazda's number for this recall is 4721B.
Model-level recall history does not show whether a particular VIN is affected or has received a repair. Check a VIN with NHTSA ↗
NHTSA investigations
0No exact-year investigations in this snapshot.
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