2019 Mazda CX-5: engine overheating

Filed May 5, 2026 · Engine · NM

Cylinder head is cracked and leaking oil. The Cylinder head has an active warranty extension but Mazda only applies this to coolant leaks and not oil leaks. The root cause is a casting defect along with a exhaust manifold design issue that imparts undue stress onto the cylinder head causing cracks. The limitation of the warranty to the type of fluid that leaks rather than the failure due to design issues with the exhaust manifold and cylinder head does not make sense given that both components have been redesigned due to the prevalance of both coolant and oil leaks from cylinder head cracks. Problem has been confirmed by Quality Mazda Service departmetn on April 4, 2026 but no warranty coverage extended to repair the failure due to the fluid leak being oil and not coolant. No warnings or messages given prior to leaks. Leaks began at roughly 76,400 miles.

Filed Apr 30, 2026 · Engine · CA

The cylinder head cracked, causing a coolant leak, which then lead to the car overheating. My car was taken into Mazda dealership because there is a warranty extension for this specific part CSP111. The Mazda dealership, corporate, and warranty department all stated the known widespread defect cracked cylinder head will not be replaced on their behalf due to an overheating code. Mazda is using a symptom as an excuse to the problem. Due to the overheating code, Mazda recommended replacing the whole engine for $10,000 with 20 hours of labor. This defect part and Mazda’s unwillingness to provide a proper solution caused my car engine to fail, posing a safety risk. No symptoms other than low coolant were present, which my car was then parked, not driven, and towed to the dealership, in hopes the warranty would be honored.

Filed Mar 9, 2026 · Engine · OH

2019 Mazda CX5 has a cracked cylinder head. This is causing oil to leak out. The oil is leaking out onto the exhaust manifold which is causing the manifold to smoke and has the possibility to catch fire. Mazda is aware of this issue and issued CSP 11( customer service program). This does not cover the oil leak, only coolant leak. Several Class Action Lawsuits have been filed. Local Mazda dealership has inspected the car and confirmed the issue. The issue occurred suddenly with no warning. Again, Mazda is aware of this issue but has failed to issue a recall or service program to fix it, this is a dangerous issue as it can lead to a fire with the oil leaking onto the exhaust manifold.

Filed Dec 9, 2025 · Engine · FL

While driving a short distance, my engine overheated and there was a strong burning smell. The cylinder head was cracked, causing a significant oil leak. The car is currently at the dealership but is available for inspection upon request. The defective cylinder head is leaking engine oil directly onto hot exhaust components. This creates an immediate risk of engine fire and causes smoke to enter the vehicle cabin, impairing visibility and driver health. The vehicle was diagnosed by an authorized Mazda dealership. They confirmed the cylinder head is cracked and requires replacement. My mechanic advised this type of leak could lead to engine overheating, sudden power loss, or potential fire risk and should not be driven. 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 problems. Mazda should be held responsible for this safety issue. Mazda is aware of this manufacturing defect but has not recalled these engines to be repaired or replaced if they are outside of their warranty period, placing costly repairs and potentially life-threatening situations on their customers. The repair is replacement of the cylinder head/sleeve or replacement of the engine block, which has since been modified by Mazda to resolve this issue. Mazda’s refusal to extend reimbursement to non-turbo owners is unfair and leaves affected customers with no support for a known manufacturing flaw. I urge the federal safety agency to investigate this recurring engine defect in non-turbo 2019–2020 Mazda CX-5 models and encourage Mazda to offer equal reimbursement.

Filed Nov 24, 2025 · Engine, Transmission · PA

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.

Filed May 27, 2025 · Engine · AR

My vehicle has 64k miles and has had regular maintenance - oil changes, etc. it has recently developed an oil leak. I took it to the dealer today & they said the cylinder head and gasket needs to be replaced. My car has not overheating or even run warm. I understand there are 2019 CX-5S that have had a casting issue with cylinder heads. I feel sure that’s what the issue is here yet they want almost $6k to repair my vehicle!

Filed Jan 3, 2025 · Engine · OH

My 2019 Mazda CX-5 suddenly developed a major oil leak within the last 7 days. My car has only 44,350 miles and I have had all scheduled and required maintenance completed timely, including oil/filter changes, coolant level checking and maintenance, etc. I took the car to an independent mechanic who diagnosed the problem as a cracked cylinder head. I then took the car to a local Mazda dealer who confirmed the diagnosis and informed me that there would be no warranty coverage as my 60,000 mile/60 month powertrain warranty had expired 60 days earlier. Some two years earlier my car's check engine light came on and overheated. I took it to the same local dealer, who replaced the coolant control valve & related components. In November 2024 I received a "Warranty Extension Program" letter from Mazda about the same fail-safe thermostat problem. I believe this is relevant and related to the cracked cylinder head since almost all instances of a cracked cylinder head are due to engine overheating. This issue put me at risk as I was close to driving the car with no oil and oil leaking heavily onto very hot engine components that could have resulted in a fire. I am now facing repairs to this car between $4,800 and $6,000 and given the faulty/defective cylinder head from Mazda, I could face this safety issue again, as it will be replaced with a similar cylinder head from Mazda!

Filed Oct 10, 2024 · Engine · VA

CX5 Cylinder head cracked at 53,500 miles. Was driving when received engine overheating and pull over immediately warning. The car smelled like maple syrup as it was engine coolant burning. Took it to the dealership and they informed me of the cylinder failure. It is currently awaiting parts and its not under warranty.

Filed Oct 2, 2024 · Engine · MN

While driving, I received a warning that the engine in my car was overheating. Upon arriving home and parking, I noticed pooling under the car. My car was due for an oil change so the next day I dropped off the car for the oil change and mentioned the overheating message and leak to the technician thinking the fix would be routine. To my surprise, I was told my vehicle had a serious coolant leak related to a cracked cylinder. I was advised to take the vehicle to a Mazda dealer. Morrie's Mazda in Minnetonka, MN confirmed the cracked cylinder head which required a full engine replacement despite the car being only ~5 years old and having ~63,000 miles. Mazda had issued a technical service bulletin on this issue but had not issued a recall. As a result, I was left with a large repair bill to replace the engine in a relatively new car. This is a serious issue and I feel Mazda put my life and others in jeopardy by not recalling vehicles and letting customers drive with the risk of the engine overheating.

Filed Sep 24, 2024 · Engine · NY

Coolant leaks at cylinder head on 2019 Mazda CX-5 Grand Touring Reserve. Mazda North American Operations released a technical service bulletin (01-013/21) regarding 2016-2020 Mazda CX-5, CX-9, and Mazda6 with SKYACTIV-G 2.5T engines. This issue can cause the engine to leak coolant, overheat, and stall, potentially leaving the driver and passengers stranded in an unsafe location. Mazda is aware of this manufacturing defect but has not recalled these engines to be repaired or replaced if they are outside of their manufacturers warranty period and placing costly repairs and potentially life-threatening situations as the responsibility to their customers. The diagnosis to repair this issue is a replacement of the cylinder head/sleeve or replacement of the engine block, which has since been modified by Mazda to resolve this issue. This is a costly repair for diagnostics, labor hours, and parts and Mazda is refusing to be held responsible for these defects outside of the power train warranty period. Mazda customer support advised this will only be potentially covered if diagnostics are completed at a Mazda dealership and does not provide any assistance if the customer uses a non-Mazda affiliated repair shop. Messaging on the dash console advised excessive heat and thermostat was nearing 260°F

Filed Sep 16, 2024 · Engine · FL

There is a coolant leak at the cylinder head. We have been told that the cylinder is cracked at the back of the cylinder head where the exhaust ports meet. The dealer's technician said there is a "redesign" in the cylinder head. This is a known issue that is a defect apparently due to Mazda's design of securing the turbo on exhaust studs that are not designed to hold the weight. Why has there not been a recall? There is a Mazda TSB - 01-013/21, issued 10/15/2021 Verbal estimate from dealer for repair - over $7,000

Filed Jun 11, 2024 · Acceleration, Engine · VT

Went to drive home from work one night, car had been normal until this event. Car suddenly began to state that it was overheating and throttled my speed down to 20 MPH. I was in the middle of traffic going 40-50 at this time. Turns out there is a VSB regarding a coolant leak that can occur and break. Nothing about how you are suddenly governed to 20 MPH