2021 Mazda CX-5 engine problems

“The contact owns a 2021 Mazda CX-5. The contact stated that while driving 50 MPH and the check engine warning light illuminated. The contact took the vehicle to an independent mechanic where an OBDII scanner discovered a misfire in cylinder#1. The vehicle was then taken to another independent mechanic where the OBDII scanner discovered a misfire in one of the engine cylinders and diagnosed the vehicle with an engine failure. The contact was then referred to the dealer who confirmed that there was a defect with cylinder#1. The dealer confirmed that the engine needed to be replaced. The manufacturer was then notified of the failure, and the contact was informed that there were no recalls on the vehicle and that the warranty had expired. The vehicle was taken to another independent mechanic and remained with the independent mechanic. The failure mileage was approximately 124,000.”

“2021 Mazda CX-5 2.5L non-turbo. While driving at approximately 8 mph, I removed my foot from the accelerator, but the vehicle unexpectedly accelerated on its own. I did not press the accelerator pedal. I had to apply the brake to slow the vehicle down. This issue has occurred three separate times, on August 25, September 4, and September 18, 2026, at approximately 70,060 miles. The same unintended acceleration behavior occurred during all three incidents.”

“The vehicle developed an engine oil leak from the timing cover due to what appears to be premature seal failure. Engine oil was leaking externally and could drip onto hot engine components, creating a potential fire hazard while the vehicle is in operation. The leak also increases the risk of low engine oil levels, which could lead to engine damage or sudden engine failure if not detected in time. This issue required an expensive repair despite the vehicle being properly maintained. I have since learned that many other Mazda owners have reported similar timing cover oil leaks on this engine, suggesting this may be a widespread defect rather than normal wear and tear. I am submitting this complaint so NHTSA can evaluate whether this represents a safety-related defect that warrants further investigation.”

“2021 Mazda CX‑5 (VIN: [XXX] ). First low‑oil warning at 17,800 miles. ([XXX]) Mazda dealership in La Crosse, WI performed an oil change and fully refilled the oil. Second low‑oil warning at 18,700 miles — only 900 miles later. ([XXX]) This indicates rapid, abnormal oil loss consistent with the known valve‑stem‑seal defect for this model year. Sudden low‑oil conditions pose a safety risk due to potential engine damage or failure. Requesting NHTSA document this issue.”

“My 2021 Mazda CX‑5 is experiencing excessive oil consumption. The vehicle is burning oil between regular oil changes, and the oil level drops noticeably before the recommended service interval. I have noticed a burning smell and/or signs of oil loss without visible leaks. This raises concerns about potential engine damage, stalling, or fire risk while driving. The issue has occurred repeatedly and does not seem normal for a vehicle of this age and mileage. I am filing this complaint because this may indicate a defect affecting engine safety and reliability.”

“Due to oil consumption issues & oil leak on 2021 Mazda cx 5 AWD I was told the timing cover and gasket needs replacement due to oil leakage. This appears to be a very common issue with this vehicle. The engine is at risk of catastrophic failure due to low oil levels”