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

Mazda has inspected the car and determined that there is a crack in the cylinder head. This is apparently a known defect in 2018-2021 Mazdas with 2.5L engines, including, without limitation, the 2018 Mazda CX-5. The cracked cylinder head has caused leaking coolant, which can drain into the engine and create serious safety issues. Mazda is aware of the issue, however, they are claiming that it is not covered by warranty.

NHTSA ODI 11705314

Hydraulic lifters keep having issues

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Driving fine at low speeds (under 40mph), once I accelerate to highway speeds the engine misfires, check engine light flashes, Smart City Brake System Malfunction, Radar Malfunction, and car losses all engine power. Car just coast, lights and brakes still work. Check engine code moves around and will be on cylinder 3 sometimes and cylinder 4 other times. Able to replicate this issue multiple times. Serious safety concern.

NHTSA ODI 11693210

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.

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Cracked cylinder head leaks oil directly onto hot exhaust, causing smoke, fumes in cabin and a fire risk.

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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

I own a 2018 Mazda CX-5. I currently have 64,770 miles on the car. I have had a burning smell and smoke coming from the engine. The car was taken to the dealer (John Kennedy Mazda Conshohocken) and I was told it was fixed by replacing a gasket. The smell and smoke persisted. I took it back to the dealer and now I am told there is a leaking cylinder head. I do not feel safe driving this car especially with my kids in the car while the engine is smoking. I have had to pull over on the highway due to this. No warning lights were on until a week prior to taking it back a second time when my oil light finally came on.

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Engine Cylinder heads started to leak at 75k miles causing oil and coolant to leak and puddle. This was after a fuel pump recall.

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Had an oil leak suddenly appear on the vehicle with only 55400 miles. Found there are technical service bulletins for this motor that the head cracks causing leaks. It is on many forums. Reached out to Mazda and got zero help

NHTSA ODI 11659102

2018 Mazda CX5 2.5 ltr engine. Major oil leak that has been diagnosed as cracked or porous aluminum casting on the cylinder block. Oil is dripping consistently out of the problem area onto the manifold, causing smoke to flow into the cabin of the car and out of the hood as well. Car is currently at a Mazda dealership for a second diagnosis that confirmed the leak. Car is 3,000 miles out of warranty. Waiting to hear what the dealership is going to do. I also have contacted Mazda corp. and have a case# to take further action if needed. As you can see by the list of "engine" complaints for this problem, it is well documented that this is not an isolated issue.

NHTSA ODI 11656944

Car started leaking and burning oil. Blue smoke coming out of engine. Low oil pressure light went on. I had it looked at by an auto mechanic. This is a major safety issue as the engine will fail because of the low pressure. The car is not drivable. Turns out it's a known issue with the cylinder head that Mazda knows about because they issued a redesign and issued recalls for the 2019 and the turbo engine. They also issued a TSB for this problem. Car is out of warranty, but not old enough to have major engine issues.

NHTSA ODI 11652887

I noticed a burning smell coming from engine. I took it to a Mazda dealership where they found a cracked cylinder head that needed complete replacing. There was no warning light or other symptoms before I noticed the smell. Vehicle has only been inspected by the dealership. Vehicle is out of warranty but only has 37000 miles on it.

NHTSA ODI 11652447

Defective Engine. Cracked Cylinder Head. Engine oil leaked overnight because of known Mazda 2.5 liter Skyactive engine defect.

NHTSA ODI 11650716

The issue began when I started to smell burning oil. As time went on smoke began to slowly come from the hood. I took my car to the mazda dealership and said that there was a cracked cylinder head in the engine. After doing research online this has been a major issue with the 2018-2020 model.

NHTSA ODI 11650580

My 2018 Mazda CX-5 with just over 45,000 miles is showing the dreaded cracked cylinder head symptoms. Coolant is leaking causing a very noticeable burning smell in the cabin and faint smoke emanating from under the hood. My CX-5 has followed the maintenance schedule at the dealership that the vehicle was purchased. At this point the dealership has not been helpful at all. Mazda MUST start including 2018 CX-5s to CSP11 (covers 2019 CX-5s).

NHTSA ODI 11648668

I own a CX5 2018 Mazda with around 31,000 miles on it. Two days ago I experienced a smoke/fume event in my car while driving. The cabin filled with burnt oil fumes and a pungent smell. I happened to be near a Mazda dealership and was able to reach it with windows down and slow driving. The dealership inspected my car and confirmed a large oil leak caused by a cracked cylinder head. I was told this is a known issue with Mazda CX5/CX9 series and that it would be covered under warranty. Today I was informed by the same dealership that my standard powertrain warranty will not cover it, as it is 60,000 miles or 5 years. My car only has 31,000 miles on it, but it’s over the 5 years by little over a year. I am looking at paying around $6,500 out of pocket to fix my vehicle. I asked if there is an extended warranty from Mazda specifically regarding cylinder heads, due to this being a known defect, however the service person said there isn’t for my car. After some online research I did come across an extended powertrain warranty applying to 2019-2020 CX5 models due to the cylinder head cracking issues. I ask that this is being looked into and that the warranty needs to be extended to the 2018 model as well.

NHTSA ODI 11646483

Cracked cylinder causes oil leak in 2018 Mazda CX-5. May occur in other model year CX-5 as well. Issue was inspected by an authorized dealer. Repair by Mazda not performed because vehicle was a few months past warranty expiration date. Issue with CX-5 cylinder-head are shown below: [XXX] [XXX] [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

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Replacement of cracked head cylinder diagnosis completed by Mazda dealer Fred beans in Willow Grove Pennsylvania Mazda is claiming they cannot cover the repair cost due to carfax not reporting all my maintenance services. After speaking to mazda customer service they confirmed that it is illegal to use carfax as documented proof. I provided proof of the maintenance aka oil change that was not eeported directly through carfax and have not heard anyrhing back. My car is under 60,000 miles and I have maintain my car and this should not be my fault this should not be my fault. Please help if possible i dont know who else to go to

NHTSA ODI 11644882

There is a cracked cylinder head cover and the oil leaks from the crack onto the manifold causing smoke and burning smell. I have read several examples on Mazda forums [XXX] ; [XXX] ) of this happening with the Mazda CX-5. A former Mazda mechanic posted he would see a couple vehicles a week at his dealership that experienced this problem. The odor of the burning oil onto the manifold is overpowering when sitting in the car. Some people with the same problem have posted they actually had small fires / burning under the car. In May, 2021, Mazda issued a technical service bulletin TSB # SA-031-21 with a cylinder head redesign for 2018/2019 CX5 models. this is telling of their awareness of the problem. There were no dashboard warnings to indicate the problem - just the burning smell from oil and oil stains in the driveway which caused me to bring the car in. There is substantial evidence that this is a common problem with these model years and it is not related to the mileage of the vehicle - mine has only 37k miles on it. It should be noted that the cylinder head is aluminum and only 2mm thick vs 5-7mm on most vehicles. Mazda should be held accountable and issue a recall and/or extended warranty to address this problem. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11644513

There is a known issue with 2018 Mazda CX 5 related to a cracked cylinder head. I have just under 60,000 miles and I noticed smoke coming from under the hood near the exhaust manifold and a strong odor of burning oil. Dolan Mazda in Reno, NV has confirmed I have a cracked cylinder head and it is the cause of the burning oil. I am concerned that oil leaking from the cracked cylinder head onto the exhaust is a fire hazard. I feel a recall should be issued.

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Cracked cylinder head

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Cracked cylinder head causing oil to leak

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What component or system failed or malfunctioned, and is it available for inspection upon request? - Engine cylinder head was broken and caused oil leakage How was your safety or the safety of others put at risk? Oil leakage resulted in a smoky smell while driving and could have led to cars on the road or my own car could have skid leading to a fatal accident Has the problem been reproduced or confirmed by a dealer or independent service center? Yes. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? Dealer has inspected. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear - No warning lamps but there was a smoky smell while driving & visible oil leak under the front hood.

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Cylinder head cracked at 46,000 miles causing smoke and oil leakage. This was the root of an almost $6,000 repair, leaving me without a vehicle for 15 days. This issue could also lead to more extensive engine problems in the future.

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At approximately 57,000 miles, the cylinder head cracked. It was leaking oil and white smoke was coming out of the engine bay. There were no warning lights. I have since gotten the cylinder head replaced.

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