There are 3 owner-reported engine complaints for the 2016 Mazda Mazda6in NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
There is a bearing in the crankshaft that looks like it’s not up to spec. No warning lights came on, car suddenly lost power on the highway. Fortunately no one was injured though it was a very scary situation. Mechanic took a look inside the engine and said a main bearing stud broke off and busted a hole through the short block. He said I’m lucky the engine didn’t turn into a grenade. Upon looking up the failure many other people have had the same issue with this engine. The exact same failure on the exact same bolt. Here are some links to some posts: [XXX] [XXX] [XXX] [XXX] Clearly I’m not the only one with this issue, and there are more examples of the same problem that you can find online through out different Mazda models that use the same engine. I can definitely have the vehicle inspected if needed, my mechanic took video of the damage as well. I could only imagine if this happened while there was more traffic on the road, it’s not safe. And the fact I can find more examples means there are probably more that never posted or reported the issue. the vehicle has less than 100k miles which a lot of the examples have the same issue at less than 100k INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
The contact owns a 2016 Mazda Mazda6. The contact stated while driving approximately 65 MPH, the vehicle lost motive power. The contact pulled over but was unable to restart the vehicle. The vehicle was towed to an independent mechanic to be diagnosed. The contact was informed that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was informed of the failure and informed the contact that the vehicle was not under warranty. The failure mileage was approximately 80,000.
MY CAR HAS BEEN SHOWING RED CHECK ENGINE LIGHT RANDOMLY FOR THE LST 3 MONTHS. IT LASTS 24 - 48 HRS, SOMETIMES AFTER OIL CHANGE. DEALER SAID NOTHING TO WORRY ABOUT, BUT I FINALLY TOOK IT TO AUTOZONE WHO SAID CODE WAS STORED AS MISFIRE ON CYLINDER 4. DEALER IS LOOKING AT IT NOW, BUT ALWAYS DISMISSED IT BEFORE. NOW THAT I KNOW IT HAS TO DUE WITH A CYLINDER - WHY DIDN'T THEY INVESTIGATE FURTHER? OF COURSE MY CAR IS ABOUT 2 MONTHS OUT OF WARRANTY AND 17OO MILES AS OF TODAY.
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 25, 2026