NHTSA Complaint #11701184 — 2019 MAZDA CX-5

What component or system failed: The cylinder head failed due to cracking around the exhaust manifold, resulting in exhaust and coolant leakage. My independent mechanic and the Mazda dealer both confirmed this was the source of the burning smell and engine risk. The failed parts are currently in the possession of the Mazda dealership and available for inspection upon request. Safety risk: The failure created a strong burning rubber smell inside and outside the vehicle while driving. My mechanic advised this type of leak could lead to engine overheating, sudden power loss, or potential fire risk if not caught early. I frequently transport children in the vehicle, and the unexpected engine damage posed a significant safety concern. Has the problem been reproduced or confirmed: Yes. The issue was first diagnosed by an independent, certified mechanic and then confirmed by the Mazda dealership, who determined the cylinder head had to be replaced due to premature cracking and leakage. Has the vehicle/component been inspected: Yes. The vehicle has been fully inspected by an independent mechanic and the Mazda dealership service department. The dealership stated the failed cylinder head will be sent to Mazda for engineering review. Were there any warning lamps or symptoms before failure: There were no warning lights or error messages prior to the failure - which is alarming. The only initial symptom was a strong burning rubber smell that began shortly before the diagnosis. No overheating warnings appeared on the dash before the problem was confirmed. Additional context: The vehicle has 40,000 miles, has been fully maintained according to schedule, and is garage-kept. The Mazda service department acknowledged this failure is unusual and premature. Mazda has issued prior Technical Service Bulletins and warranty extensions for similar cylinder head/manifold cracking issues on the 2.5L turbo engine, but no program exists for the non-turbo engine, despite identical symptoms.