2021 Mazda MAZDA3
Problems, recalls and owner-reported issues
Engine is the leading concern among 52 owner complaints filed for this model year. This is the 17th highest complaint count among 22 MAZDA3 model years with reports.
Of the 2021 reports, 2 involved a crash and 2 involved a fire. 1 person was injured.
What owners report most often
Recalls and investigations
Tires, valveFeb 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.
A sudden air leak from the tire air valve may cause a loss of vehicle control while driving, increasing the risk of a crash.
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.
Campaign 21V101000 on NHTSA.gov
Representative owner complaints: power train
4 reports, newest first. Show all
Power train, Sep 28, 2026
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 replaced under warranty. Noticed faint high pitched sound coming from rear in months leading up to incident. Had differential and transfer case fluid changed less than 1000 miles and 1 month before incident making me wonder if fluid was underfilled/wrong fluid used or the diff was just bad.
Power train, Jan 25, 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 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
Power train, May 27, 2025
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.
Power train, Nov 26, 2024
Radiators are failing 3 years after the warranty period. Its leading to coolant lost and perhaps overheating the engine.