2019 Mazda CX-5

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

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.

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?

My car has an issue officially diagnosed by a reputable mechanic that matches the claim of the former TSB SA-058/20 that was changed and clarified through the now existing TSB SA-031/21. My car has a cracked cylinder head. This is the non turbo engine but it does have cylinder deactivation which his believed to be a culprit. The cracking is known to be caused by a manufacturing defect. There is an existing class action lawsuit regarding the turbo versions. There are complexities as to wh this lawsuit is on behalf of the turbo engines, and not the non turbo engines, however the same problems are well documented and widely acknowledged throughout hundreds if not more instances of people online and by Mazda's acknowledgment of the problem through the TSB's. This put me at great safety risk. I was driving north bound right beside semi trucks and busy traffic at speed limits of 70 mph when my engine started smoking. I was able to pull over and get it to a nearby mechanic. They officially diagnosed the vehicle w the cracked cylinder head matching the aforementioned TSBs. Mazda denied my goodwill case, even though it was made without complete information on my situation and car, despite my best attempts to get to the one representing my case with the dealership(I tried to reach him for 2 days with no success). Getting a repair from Mazda dealerships was inconvenient for my location and schedule, but I've always had my vehicle properly serviced. Mazda said this repair would cost near $7500. A mechanic quoted me at least the amount of $5500.

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.

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 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.

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.

My 2019 Mazda CX-5 with approximately 78,000 miles developed a sudden major engine oil leak. The Mazda dealership diagnosed the issue as a cracked cylinder head and quoted approximately $5,600 for repair. The vehicle was properly maintained and this failure occurred without warning. A cylinder head failure at this mileage appears premature and may represent a defect. The oil leak created a large puddle under the vehicle and could pose a potential safety hazard due to loss of engine oil.