What 113 owners told NHTSA about the 2018 Mazda Cx-50

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 (NHTSA). 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.

NHTSA ODI 11747660

Cylinder head suddenly cracked, causing heavy oil leakage onto hot exhaust manifold. Car started to smoke heavily. Vehicle turned off before potential engine fire.

NHTSA ODI 11744932

2018 Mazda CX-5 AWD with 2.5 L engine, non turbo. Car has 98,914 miles. Rear differential started leaking oil. Dealer stated that the differential needs to be replaced, for $5,003.33. Manual does not provide for oil change intervals. Lifetime oil. 98K must be the life expectancy. Has not been fixed yet. Sitting in the garage dripping oil onto a piece of cardboard. independent shop looking for a low mileage used differential.

NHTSA ODI 11742164

Like many other complaints. My 2018 Mazda cx5 GT is having the same issue with the cracked cylinder head. I only have about 36-38k mileage on it ( I forgot the exact). Mazda dealership will not cover the cost. NEVER had an accident to the front and only one accident to the back when I got rear ended in 2019. If this is a wide spread issue, why is this not a recall? and why is it only the turbo engine gets extended warranty? The repair cost right now approximately $9,500. I never do any maintenance at Mazda so I doubt they will give me the good will assistance but I am still waiting for an answer. I hope NHSTA will do something because this issue will continue with all other owners that have the same year model.

NHTSA ODI 11738405

My 2018 CX5 just hit 50,000 miles recently and I smelled something burning and saw smoke coming from the hood while I was stopped for a school bus. I immediately stopped driving due to fire concerns. The vehicle has a cracked cylinder which is a known issue for this vehicle. Mazda has no plans to correct this issue other than issuing a technical bulletin. I feel that Mazda should repair this at their cost because it is a defect and the vehicle only has 50,000 miles. Instead I have to pay nearly $5,000. This is hard to believe! Transcript from dealer: The technician reported an oil leak from the cylinder head, specifically indicating a crack in the number four lifter valley that is causing fluid to leak down the engine block. This issue is recognized as a known problem, and the technician will check if it is covered under warranty. Repairing the cylinder head will require significant labor, including dropping the engine, and will take some time to complete. Services being performed: - Oil change. - Inspection for oil leak issue. Recommendations: - Replacement of the cylinder head due to the identified oil leak. Multi Point Inspection $4870.22

NHTSA ODI 11738150

Upon acceleration it’s not shifting gears properly. The rpm’s rev but the vehicle doesn’t go faster. Traffic behind me continued to accelerate to where i was concerned about being rear ended. I Have not taken it to anyone yet..it has done this a couple of times. Even though it’s a 2018 it only has 25000 miles on it. The dealer is an hour away and i”m afraid to drive it there because i don’t want to cause more problems. No warnings lights or messages.

NHTSA ODI 11732799

2018 Mazda CX-5, 58,182 miles. Report date is 3/7/2026, low mileage for it's age. Vehicle has been exclusively purchased and serviced at the same authorized Mazda dealership for the lifetime of the vehicle, with all maintenance records on file. I began experiencing a strong burning oil smell inside the passenger cabin while driving. The fumes were noticeable to both the driver and passengers, creating a potential carbon monoxide/combustion fume exposure hazard that posed a safety risk to all occupants. Upon bringing the vehicle to the dealership, the technician diagnosed a cracked cylinder head requiring full replacement. This is a significant structural engine defect. Despite the vehicle being dealer-serviced its entire life, the repair cost was initially placed entirely on the owner. Mazda eventually provided partial financial consideration, though the root cause of why a cylinder head cracked on a well-maintained 58,182-mile vehicle was never adequately explained. I am filing this complaint because fumes entering the passenger cabin represent a serious safety defect, and I believe this issue may affect other 2018 CX-5 owners.

NHTSA ODI 11722750

the cylinder head has a crack in it witch sprays oil all over the engine.it also sprays oil on to the very catalitic converter that's very hot .smoke is everywhere and iam afraid it will cause a fire

NHTSA ODI 11685332

Smelled smoke (burnt oil) for over a year. Dealer could not address. Finally found that the cylinder heads had cracked and required replacement at $7500. Car was only 51K miles.

NHTSA ODI 11644638

The cylinder head on my 2018 Mazda CX-5 developed cracks on the exhaust side, leading to significant oil leakage onto the exhaust manifold. This has caused engine damage and safety concerns. The vehicle is currently at a Mazda dealership, where the issue has been inspected and documented. The component is available for further inspection upon request. The oil leaking onto the exhaust manifold creates a serious fire hazard due to the high heat generated in this area. Additionally, the vehicle experienced burning smells and visible smoke coming through the air vents, which could impair visibility or cause distraction while driving. These conditions place the safety of myself, my passengers, and others on the road at risk. The issue has been confirmed by a Mazda dealership. They provided a video showing oil actively dripping from the cracked cylinder head and stated that the engine requires a full replacement. Mazda dealership video: [XXX] This video contains the engine inspection findings conducted at the dealership during my recent visit. It clearly shows the damage and highlights the issues identified. The vehicle has been inspected by the Mazda dealership service team, who identified the cracks in the cylinder head and documented the oil leakage and related engine damage. There were no warning lamps or messages on the dashboard prior to the failure. The symptoms began with a noticeable burning smell inside the cabin, followed by a slight mist coming out of the air vents and smoke from under the hood. Oil leakage was later observed on the ground, and the coolant level appeared empty. I’ve received a video inspection of my vehicle from the service center on March 7, 2024 with no concerns at that time, which you can view here: [XXX] . This link leads to TruVideo, a platform that many dealerships use to share service videos with customers. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11631241

This car has a confirmed cracked cylinder head and is leaking oil. This is a known issue and there is a TSB out for it. It happened at $62500 miles and is just outside of the warranty. This has happened to several of these cars. Mazda is not doing "good will" to repair them and there is not yet a recall which there should be. The car suddenly started leaking oil and smoking/burning. It is unsafe and a defective cylinder head. Mazda should be taking responsibility for this

NHTSA ODI 11626592

2018 mazda started smoking from under hood and noticed a burning oil smell. Took to mechanic and was told engine head gasket has a huge Crack. Car only has 22k on it and never been in any accident. All appropriate preventative services are up to date. There was no indication light no warning light nothing to identify why the car was leaking oil and smoking until it was looked at. This has multiple.complaints in regards to this specific year and model and needs to be addresses before someone's car catches fire or stalls in the middle of highway

NHTSA ODI 11592587

Cracked cylinder head. Burning oil smell. Coolant leaking into oil. Car purchased a year ago for $21,500. Dealer I bought it from paid 1/2 after sending it out to Mazda to be diagnosed and fixed.

NHTSA ODI 11585016

Noticed an oil smell when driving the vehicle, slightly premature to when it was due for an oil change. Engine was emitting light blue smoke when parked after driving for more than 20 minutes. Took the car to a Mazda dealership to get serviced two days after noticing the issue and was told that the cylinder head was cracked and needed to be replaced. There was oil leaking from the vehicle, which I had not noticed, and it had soaked a lot of the front undercarriage of the car. Research into the effects of an oil leak indicate that it can cause a serious malfunction of the engine and other components of the car, but I did not experience that in the time of noticing the problem and taking the vehicle to get serviced. The problem was diagnosed by the service department at a Mazda dealership and is being repaired there. The oil indicator came on a day after noticing the smell.

NHTSA ODI 11582620

Noticed a burning oil smell coming from the car along with leaking oil in the driveway. Vehicle has 53000 miles on it and was 3 months out of powertrain warranty but still under the 60000 mileage cap. Local Mazda dealership came back saying that it was a "SA-037/23 Oil leak at cylinder head, cylinder head replacement with parts kit" and quoted $5100 to repair. Dealership stated that the vehicle was unsafe to operate. There were no dash indicator lights or symptoms of overheating to indicate that there was a problem outside of the smell. After the diagnosis was made, we researched and found that this was a commonly reported problem for this model year

NHTSA ODI 11582662

2018 Mazda CX-5 with roughly 52,000 miles on it was emitting a burnt rubber smell and white smoke from the engine. Repair shop thought it was a bad timing lock. Replaced that and car continued to emit white smoke and smell like burnt rubber. Engine then began leaking oil. Took the car back to the repair shop and it was confirmed that the engine had a cracked cylinder head. The repair shop said this is a known issue with 2018-2019 Mazdas. In three days time, the engine leaked roughly 1 quart of oil and was deemed not safe to drive by the repair shop.

NHTSA ODI 11578862

Oil leak. Smoke from the engine. Inspected by the local body shop, we were told that the leakage would probably come from cylinder head. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11544817