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.

The Cyclinder Head cracked. This could cause the engine to fail, and leaving the driver on the highway or other unsafe locations of travel. The certified repair shop along with the insurance adjuster advised it was a manufacturing defect. The warning sign was an oil burning smell inside the vehicle while stationary and inside the garage.

Timing chain gasket leak, causing oil to go everywhere and smoking could cause a fire

Confirmed cracked cylinder by dealership, led to dumping of oil while vehicle was in motion on the highway. Vehicle/engine could have caught fire at any moment. There were no engine warnings that appeared on the dash. This is consistent with other CX-5 complaints on NHTSA. Vehicle had 55,000 miles on it at time of incident, and needed $8,000 worth of repair. Please recall!!

In August 2025, we brought our Mazda CX-5 (non-turbo engine) to a Mazda service center and paid nearly $3,000 for repairs, including replacement of belts and other related service. Despite this, we continued to experience a burning smell from the vehicle. Shortly thereafter, the problem escalated — the burning smell persisted and smoke began to appear. Mazda is now demanding an additional $4,500 to replace a cracked cylinder head. This defect must have been present when the car was serviced in August, and the initial repairs failed to identify or correct it. While there is an NHTSA Technical Service Bulletin for the turbo version of this engine, there are numerous complaints online about the same defect in the non-turbo model, which is what we own. This indicates that the problem is not isolated. Mazda should be held responsible for this safety issue. A cracked cylinder head that leads to burning smells and smoke is a serious hazard that could cause engine failure or even fire. Consumers should not be forced to spend thousands of dollars on repairs for what appears to be a widespread defect and when our vehicle has only $50k miles and it should last for the life of the vehicle.

Cracked/Leaking Cylinder Head on my 2019 Mazda CX5. It is understood that Mazda has extended warranty for the Turbo Model (CSP11) of this car, but not the standard engine, even though they both are displaying the same issue in many 2019 CX5s. Quoted at $6000 for a vehicle under 90K Miles. Issue needs to be escalated.

The contact owns a 2019 Mazda CX-5. The contact stated that while driving 30 MPH with a toddler occupying the rear seat, the contact noticed smoke and an abnormal burning rubber odor coming through the vents. The contact pulled into a gas station and then pulled into a nail salon parking lot. There was no warning light illuminated. The contact was able to drive to the residence, where an independent mechanic inspected the vehicle and found an oil leak, and the mechanic diagnosed that the cylinder head had cracked. The vehicle was taken to the dealer. The dealer informed the contact that the repair could not be covered under an unknown Extended Warranty because of the type of engine. The manufacturer was notified of the failure and informed the contact that the repair could not be covered under Goodwill assistance because the oil changes had not been mainly performed by the dealer. The vehicle was not repaired. The failure mileage was approximately 83,000.

Cracked Cylinder Head.