2018 Mazda CX-5: engine failure

Filed Jul 22, 2026 · Engine · CA

I am writing to formally document a significant engine failure on my 2018 Mazda CX-5 Grand Touring (VIN: [XXX], License: [XXX], Odometer: 78,159 miles). The vehicle began exhibiting visible smoke from under the hood and severe oil leakage — oil was actively pooling beneath the car and leaving a trail. Upon inspection by Cal West Auto Center (San Marcos, CA), the vehicle was diagnosed with a leaking cylinder head gasket requiring full cylinder head removal and replacement. I am aware that Mazda issued Technical Service Bulletin TSB #SA-031-21 specifically addressing a cylinder head casting defect in 2018–2019 CX-5 models equipped with the 2.5L Skyactiv-G engine with cylinder deactivation — the exact configuration of my vehicle. This is a documented manufacturing defect, not normal wear and tear, and the repair estimate I have received is $4,800.84. Given that this failure is tied to a known defect acknowledged by Mazda, I am requesting that Mazda Motor America cover the cost of this repair in full, or provide a clear explanation of what goodwill or warranty coverage is available to me. I am happy to provide the repair estimate, vehicle documentation, and any additional information needed to process this request promptly. Thank you for your attention to this matter. I look forward to your response. [XXX] Cell: [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jul 1, 2026 · Transmission · CA

My Mazda 2018, CX-5, Grand Touring, was diagnosed with a cracked cylinder head at 64,599 miles. This issue could posed a safety hazard for not only us but others on the road by: *Engine Failure / Sudden Loss of Power-A crack allows coolant and oil to mix or leak, leading to overheating and potential catastrophic engine seizure. A seized engine can cause sudden, unexpected loss of power — especially dangerous at highway speeds or during lane changes/merges. *Oil and Coolant on the Road-Leaking fluids drip onto the roadway, creating slick surfaces for motorcyclists and other vehicles — similar to a spilled oil hazard. This is especially dangerous on curves and in wet conditions. *White Smoke / Steam Billowing from Exhaust-When coolant enters the combustion chamber, it burns off as thick white smoke. This can instantly reduce visibility for drivers behind the vehicle, potentially causing rear-end collisions. *Fire Risk-If oil leaks onto hot exhaust manifolds or engine components, it can ignite. An engine fire can spread quickly and, in traffic, puts surrounding vehicles and occupants at risk. *Debris from Engine Destruction-In extreme cases, a severely overheated or seized engine can cause internal components to fail violently. Debris from a catastrophic engine failure can damage undercarriages of nearby vehicles or become road hazards. *Stalling in High-Risk Locations-A vehicle that stalls due to engine failure in a tunnel, on a freeway on-ramp, in an intersection, or on a bridge creates an immediate collision risk for surrounding traffic. This is part of why Mazda's handling of the cylinder head defect is so problematic — it's not merely a costly repair, it's a public safety issue that arguably warrants regulatory attention (the federal safety agency). We had NO warning lights, no overheating issues. Repairs have been made to the cost of almost $5400.00 *Please note there are many, many people complaining of this same issue on this model of car in multiple on-line forums.

Filed Jun 17, 2026 · Engine · CA

I am submitting this complaint regarding a cylinder head failure on my Mazda CX-5. The vehicle has approximately 53,000 miles and has been properly maintained throughout its service life. The vehicle developed a crack in the cylinder head, which was subsequently confirmed by an authorized Mazda dealership. Mazda has previously issued a Technical Service Bulletin (TSB) addressing cylinder head cracking on certain vehicles; however, my vehicle's VIN is not included in the covered range despite experiencing the same failure described in the TSB. The dealership initially provided a repair estimate of $8,789 plus tax to replace the cylinder head. Following further discussions, the dealership reduced the repair cost to $3,903 plus tax. They recognize that this crack is not part of normal wear and tear but due to the VIN number not being included in the recall are unable to provide full coverage. A cylinder head crack is a major engine failure that should not occur on a well-maintained vehicle with only 53,000 miles. I am concerned that vehicles outside the VIN range identified in Mazda's TSB may be experiencing the same defect and that the scope of the issue may be broader than currently recognized. The vehicle was purchased used from the same Mazda dealership that diagnosed the failure and is currently performing the repair evaluation. I respectfully request that the federal safety agency review this issue to determine whether additional Mazda CX-5 vehicles may be affected by the same cylinder head defect despite not being included in the existing TSB.

Filed Apr 30, 2026 · Engine · NV

My 2018 Mazda CX five experience catastrophic engine failure at approximately 119,000 miles despite proper maintenance. The failure resulted in a repair estimate exceeding $9500. This type of failure raises concerns regarding potential engine defects or premature mechanical breakdown. Mazda acknowledged the issue by offering a minimal Goodwill payments, but refused meaningful assistance. I am reporting the issue to determine whether similar failures are occurring with Mazda and further investigation is warranted.

Filed Apr 9, 2026 · Driver assistance, Engine · MO

I am reporting a safety issue involving engine failure and fumes entering the vehicle cabin as well as unintended braking post major engine repair at 75,000 miles on my 2018 Mazda CX5. My vehicle developed engine problems consistent with a cylinder head/coolant defect and began allowing fumes/smoke to enter the cabin while driving. This created a health and safety concern for occupants. I reported this to the dealership and was told the vehicle was safe to drive despite the presence of fumes in the cabin. A major engine repair was later performed. A few days following the repair, additional warning lights and system malfunctions appeared, including brake system warnings, and the vehicle later braked unexpectedly while driving nearly causing me to be rear-ended. The vehicle has been inspected by the dealership, but the root cause of the fumes and subsequent safety issues has not been clearly explained. This situation created a safety risk due to exposure to fumes inside the cabin and unexpected vehicle behavior while driving. Smoke/fumes video and any additional documentation can be provided upon request. Attaching the costly invoice as well.

Filed Mar 30, 2026 · Engine · CT

Vehicle Information Year/Make/Model: 2018 Mazda CX-5 Engine: 2.5L Mileage at Failure: Approximately 115,000 miles Component: Engine Complaint Summary: I am reporting a sudden and unsafe engine failure involving a cracked cylinder head in my 2018 Mazda CX-5. This failure occurred without warning at approximately 115,000 miles and resulted in significant oil leakage from the engine. Description of the Failure and Safety Risk: While operating the vehicle, I detected a strong burning oil odor followed by visible smoke coming from the engine compartment. Upon inspection, it was determined that the cylinder head had cracked, allowing engine oil to leak onto hot engine and exhaust components. This condition presents a serious safety hazard, including the risk of fire due to oil contacting high-temperature surfaces. Notably, there were no warning lights, messages, or prior indicators of any issue before the failure occurred. The vehicle has been properly maintained and has not experienced overheating or misuse that would reasonably lead to this type of failure. Repair Information: The vehicle was diagnosed by an authorized Mazda dealership, which confirmed a cracked cylinder head. The estimated cost of repair is approximately $5,130. Additional Information / Defect Pattern: Through independent research, I have identified multiple reports of similar failures involving Mazda 2.5L engines in comparable vehicles. These reports describe nearly identical symptoms, including sudden oil leakage, smoke, and cracked cylinder heads at relatively low mileage. This pattern suggests a potential manufacturing or material defect rather than normal wear and tear. Manufacturer Response: I have contacted Mazda Customer Experience and escalated the matter. Mazda has declined to provide any assistance, citing the vehicle being out of warranty, despite the nature of the failure and associated safety concerns. Summary: This issue involves a critical engine component failure that can le

Filed Jan 29, 2026 · Engine · PA

While driving, my 2018 Mazda CX-5 experienced a sudden and complete loss of engine power without warning. The engine shut down while the vehicle was in motion; however, electrical systems such as the radio, heat, and electronics remained operational. The vehicle lost propulsion, creating a serious safety risk in traffic. The vehicle had recently been serviced at an authorized Mazda dealer for completion of PCM and fuel-system recalls. Shortly after recall service, the engine failure occurred. No warning lights or prior symptoms were present. An independent mechanic suggested possible engine seizure, but a full diagnostic evaluation (including compression testing or internal inspection) has not been completed. The cause of the sudden power loss remains undetermined. This incident represents a potential safety defect involving unexpected engine shutdown and loss of propulsion.

Filed Oct 7, 2025 · Engine · MA

2018 Mazda CX-5, 2.5L Naturally Aspirated Engine The vehicle has been diagnosed with a leak from the cylinder head cover, resulting in engine oil dripping directly onto the exhaust manifold. This issue causes noticeable smoke and a strong burning oil odor inside the cabin while the engine is running. This defect presents multiple serious safety concerns: 1) Health hazard due to prolonged exposure to burning oil fumes inside the vehicle. 2) Fire risk from oil contacting hot engine components. 3) Potential engine failure, which could lead to vehicle stalling or loss of control, increasing the risk of a crash and possible loss of life. Mazda issued Technical Service Bulletin TSB #SA-031-21, which introduced a redesigned cylinder head for 2018–2019 CX-5 models. The release of this TSB indicates Mazda’s awareness of the underlying design flaw. There is substantial evidence, including numerous owner reports, that this is a widespread issue affecting these model years. The defect is not related to vehicle mileage or user negligence. Mazda should be held fully accountable and take corrective action by issuing a formal safety recall or offering an extended warranty to affected owners. Immediate attention to this matter is necessary to protect consumer safety and prevent future incidents.

Filed Aug 22, 2024 · Engine · CA

Engine seems that it cracked. The car has 66K and has good maintenance record. I took my 2018 CX5 to Mazda for a possible oil leak. Mechanic says block has hairline crack, is leaking oil down exhaust manifold and engine needs to be replaced. It seems a known issue with this model & Mazda is aware of the problem. There is no recall or class action lawsuit that either of us found. Mazda has said this car in no longer under warranty. It has 66K and the engine is broken?

Filed Apr 25, 2024 · Engine · NY

The cylinder head cracked and broke resulting in a massive oil leak that covered all the parts under my car and under the hood and engine which in result started to smoke. This is not only a major issue of extremely costly repairs but more importantly also serves as a major safety issue. This could had caused fire to the vehicle and also engine misfire resulting in engine failure while in drive and potentially lead to critical injury or death for me and my family. Mazda was aware of their poorly designed engineering for this critical and extremely important component and it is known Mazda recognized the issue by issuing a TSB. After further research there are numerous TSB issued for multiple engine failures with Mazda. It is also known that certain VIN number vehicles manufactured with this defect are commonly reported and have experienced this exact same issue within only a few years and or very low mileage. This is a major mechanical failure to happen to vehicles within a short time span of purchase and results in loss of customer trust and loyalty. As a first time car buyer I am deeply dissatisfied and disappointed with Mazda. I would not had purchased a brand new car if I would had known I would experience this only at 5 years and 71 thousand miles. My vehicle was inspected and diagnosed by a certified Mazda dealership. I was advised and informed that this is a huge issue that has happened with all customers. Mazda knowingly neglected the proper manufacturing and engineering for the cylinder head and other engine parts, which is the most critical component to any vehicle to function and operate. Lastly what is more concerning was that there was no warning signs such as lights or sensors that were triggered as warning of the issue and vehicle failure posing as another safety concern for drivers.

Filed Mar 4, 2024 · Engine · MA

There was a TSB #[xxx] for the repair of Cracked Cylinder Head(s). Our 2018 CX-5 incurred a Cracked Cylinder Head at 5,418 miles. This was under the 60,000-mile power train warranty, but after the 5-year term had expired ([XXX]). Our issue started in late January '24. The car had been serviced at the Mazda Dealership in Hyannis, MA until my wife bought a '21 CX-5 model and gave the '18 model to our college son in FL. The TSB was for '18 - '20 models - which has now been increased to the '23 CX-5s. Mazda US would not help us in any way with the engine replacement that the Mazda dealership in Tampa replaced with a '23, 4,000-mile engine. $ 7,462.89 'new' engine that has a '23 engine that could incur the same issue! Also, my wife's newer model, '21, could also be a lemon for the TSB. We're looking for Mazda to step up for it's (loyal) clients! The work was completed and paid for on [XXX]. Mazda reviewed our case ([XXX]) and declined to assist. A reliable vehicle, Mazda, with an engine at 54,000 miles should be cared for by the manufacturer. The reason the time expired and the mileage was low was due to the lack of driving during the Covid era. We have researched online the number of cases for Mazda and the CX-5's issues with the cylinder heads. We are looking for a government interaction to assist consumers like us. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Feb 27, 2024 · Engine · MA

Engine head has crack on it, causing oil to leak out and burn and smoke. In order to replace the engine/crack, manifold need to be removed. Leakage is in the back of the engine. This must be manufactured defect. My mazda has less than 45000 mile on it. Unfortunately warrantly is no longer valid. Unless a recalled is issue, a repair will be free of charge to current owner. Other wise operator has to constantly keep adding oil.