Engine owner reports: Mazda CX-5 years in the records

The records describe a possible fatal outcome.

“The cylinder head has cracked and is leaking externally. The engine oil that is leaking out is leaking directly onto the hot exhaust manifold. This can place us as risk due to the engine oil getting ignited by the hot exhaust manifold. There were no warning lamps that came on but there was a smell of burning oil that all of a sudden came up through the vents. This vehicle is currently at Woodhouse Mazda in Bellevue, NE and they have confirmed that the leak is active and has damaged the engine beyond repair.”

The records describe a possible fatal outcome.

“I am the owner of a 2019 Mazda CX-5 with approximately 50,000 miles. I am experiencing an active engine oil leak accompanied by a burning smell and visible smoke from the engine compartment. This is consistent with a cracked cylinder head assembly — a known manufacturing defect in 2018–2021 Mazda CX-5 vehicles documented in Mazda's own Service Alert SA-031/21, which Mazda characterizes as a fire hazard. Despite this, Mazda has extended warranty coverage only to turbo-equipped models (Program CSP11), leaving non-turbo owners with the identical defect unprotected. At only 50,000 miles, this is a premature failure caused by a manufacturing defect — not normal wear and tear. Oil leaking onto a hot exhaust manifold constitutes a serious fire risk to vehicle occupants and the public. I am requesting that NHTSA investigate this pattern of failure across 2018–2021 Mazda CX-5 non-turbo models and consider whether a formal recall is warranted. I have contacted Mazda North American Operations directly requesting goodwill warranty coverage and have a case number on file. I have yet to hear a response but was initially informed my car was out of warranty.”

The records describe a possible fatal outcome.

“The engine has an oil leak from the head. It is a common problem with this year and make. It is a manufacturer's defect called a porous head where oil leaks through the casting not a seal. I've already spent $2000 to repair but still leaks. Oil leaks onto the exhaust and smokes causing fumes in the inside of the car and can be a fire hazard. Mazda is well aware of the problem but has yet to address it.”

The records describe a possible fatal outcome.

“We began occasionally smelling an acrid smell, but didn't think much of it due to lack of visible leaks or warning lights. During a routine oil change at the mazda dealer, we asked about the smell, and the tech almost immediately found the issue, saying he had seen it a few times before. The oil is leaking from the head down onto the manifold due to what seems to be a recurring defective casting issue. quote from mazda dealer service department "During the vehicle's inspection, found oil leaking from the engine. A further inspection found the oil to be leaking from behind the cylinder head near the exhaust manifold. oil is leaking through the casting of the cylinder head it appears. will recommend replacing the cylinder head due to the oil leak."”

The records describe a possible fatal outcome.

“Cylinder block cracked on back side of engine. This crack leaks oil onto the exhaust manifold. Condition Confirmed by Mazda dealer. Oil burns on the exhaust filling the cabin with smoke impairing the driver. Also a high risk of combustion in the engine compartment Inspection report and pictures available. No sign or warning of issue. Crack happened on a daily drive to work. No engine lights noise or smell until head suddenly cracked causing a large oil leak. Mazda has an internal TSB 01-002/23 admitting that these cars in this year range have a manufacturer defect in the block”

The records describe a possible fatal outcome.

“On May 11th I was driving my 2019 Mazda CX-5 with approximately 35,000 miles when my cabin filled with the smell of gasoline. The smell became overwhelming within minutes, causing concern for my safety and the safety of other drivers. I immediately drove to the closest auto repair/body shop for an emergency inspection. Upon inspection, the technicians discovered there was a "crack at rear cylinder head and leaking oil excessively. Oil is leaking on to hot exhaust manifold....car is not safe to drive since oil leak is excessive". I was advised that this must be a manufacturer defect as you should not see this issue at such low mileage. The vehicle was then towed to the nearest Mazda dealership/service center, where a cracked rear cylinder head was diagnosed and confirmed. I was informed that continued operation of the vehicle could have resulted in catastrophic engine failure, engine seizure, fire risk from leaking oil contacting hot engine components, or sudden loss of power while driving, creating an extremely dangerous driving situation. Prior to the failure, there were no major warning indicators other than the sudden strong fuel/oil smell. The issue occurred unexpectedly despite the vehicle being properly maintained and having low mileage for a major engine failure. I have been the sole owner. The vehicle is currently available for inspection upon request.”

The records describe a possible fatal outcome.

“My 2019 Mazda CX-5 (equipped with the 2.5L naturally aspirated SkyActiv-G engine with cylinder deactivation) has experienced a severe structural failure resulting in a cracked engine cylinder head. This casting defect allows pressurized motor oil to leak continuously from the cylinder head down onto the hot engine block and nearby exhaust components. This has led to the following severe safety risks: engine oil is leaking onto the exhaust manifold and creates an extreme risk of engine compartment fire when the vehicle is in motion; sudden loss of oil pressure or complete structural failure of the cylinder head can cause the engine to stall or seize unexpectedly without warning, completely disabling the vehicle in live traffic and creating an imminent crash hazard; and dropping oil levels and leaking fluids burning against the engine produce strong smoke and chemical odors that enter the cabin, which can cause driver distraction and severely limiting visibility if smoke escapes through the hood. We are also inhaling these odors. Mazda is fully aware of this structural engine defect and has detailed it internally under Technical Service Bulletin TSB #SA-031-21 (as well as related TSBs for oil seepage/leaks on these cylinder heads). Despite acknowledging the manufacturing flaw, Mazda has failed to issue a safety recall for this dangerous fire and stalling hazard, forcing consumers to drive unsafe vehicles or pay thousands of dollars out of pocket for a known defect. The vehicle currently has 62,317 miles. The crack and oil leak were officially diagnosed by the Carlsbad Mazda dealership service department on 5/26/26. I am requesting that the NHTSA launch a formal safety defect investigation into Mazda 2.5L cylinder head cracking to force a safety recall before this defect leads to a fatal fire or highway accident.”

The records describe a possible fatal outcome.

“This 2019 Mazda CX 5 is experiencing a crack in the oil cylinder. THis appears to be connected to: There is no official, broad NHTSA recall for cracked oil cylinders in the 2019 Mazda CX-5, but Mazda has issued a Technical Service Bulletin (TSB #SA-031-21) to address this known issue. It affects certain 2018–2021 CX-5s, particularly those with 2.5L engines, where a cracked cylinder head leaks coolant or oil. If this is a known issue with this vehicle, why has a recall not been addressed?”

The records describe a possible fatal outcome.

“I own a 2019 Mazda CX-5 with approximately 36,000 miles. The vehicle developed a strong burning oil smell while driving, particularly through the HVAC/vent system. I initially reported the odor to a Mazda dealership, but no issue was identified. Approximately two months later, the smell returned and worsened. The vehicle was later diagnosed by a Mazda dealership with an oil leak originating from the cylinder head near the exhaust manifold. According to the repair documentation, oil was accumulating on the exhaust due to seepage from the cylinder head. The repair required full cylinder head replacement. This created significant safety concerns because leaking oil was contacting hot engine/exhaust components while the vehicle was being operated. Burning fumes entered the passenger cabin through the vents while driving. I was concerned about the risk of fire, smoke inhalation, sudden oil loss, and possible engine failure while on the road. There were no warning lights prior to the failure. The primary symptom was the persistent burning smell. The dealership replaced the cylinder head. The original repair estimate was approximately $6,000. Mazda later provided partial goodwill assistance, but I was still required to pay approximately $2,500 out of pocket. After researching this issue further, I found numerous similar NHTSA complaints involving 2019 Mazda CX-5 vehicles experiencing cylinder head leaks/cracking near the exhaust manifold, burning smells, smoke or fumes entering the cabin, and major engine repairs at relatively low mileage. Mazda has acknowledged similar cylinder head concerns in CSP11 and TSB 01-002/23 for certain VIN ranges but denied coverage for my vehicle because the leak involved oil rather than coolant and because my VIN was outside the covered range. I am requesting that NHTSA investigate whether this represents a broader cylinder head defect affecting additional 2019 Mazda CX-5 vehicles outside the currently covered VIN range.”

The records describe a possible fatal outcome.

“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.”

The records describe a possible fatal outcome.

“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.”

The records describe a possible fatal outcome.

“A Mazda Dealership should me a Mazda cx5 2019, in 2023, at nearly 38k miles, right about where many have reported a cracked cylinder issue due to a manufacturing issue in age, and in milage. There is a lawsuit ongoing regarding the turbo version, however many reporting the same issue in the non turbo versions. My engine started smoking while on the highway causing a highly dangerous scenario to which I was barely able to make it to a mechanic where all the oil spilled out upon arrival. I got a diagnostic from a reputable mechanic confirming the cracked cylinder.”