2018 Mazda CX-5 Engine
Owner-reported problems and safety issues filed with NHTSA. Review common failures, severity levels, and complaint trends over time.
Complaint Timeline
Chronological view of owner reports
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)
Cracked cylinder head
Cracked cylinder head causing oil to leak
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.
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.
Purchased vehicle from dealership drove 1650 miles, cylinder head began leaking, excessive oil. Took vehicle to repair shop their assessment cracked cylinder head. Warranty expired, dealership refused help in addition to Mazda Corp. unless brought to nearest dealership 140 miles away, with no guarantee. Vehicle is not driveable, I do have photos of the cracks.
We are a senior citizen couple driving this 2018 Mazda. Went out to garage to find a significant size area of oil spillage on the floor. The car has just over 25,000 as we are low mileage drivers. Took to a mechanic to find out it is a cracked head and oil is steaming out of the crack.i have since learned that Mazda is well aware of the weakness in this model and has chosen not to do anything about it. Our car is out of warranty. It would be a hardship for us to repair. And if repaired, would it happen again? This has recall written all over it, as well as a class action suit. I would like our vehicle repaired at no cost to us. How long were they aware of this issue? I have found hundreds of complaints. I prefer not to pursue this legally but this is unacceptable by Mazda. This was my second Mazda purchase but will be my last if they cannot stand behind their products.
2018 CX-5 has a cracked or porous (depending who is telling me the issue) cylinder head at 60000 miles. I was told by the Mazda service advisor that the issue is common. I reached out to Mazda for assistance in covering their faulty part and was told they would not cover any of it.
Vehicle has a cracked cylinder head at 43,000 miles. It is leaking oil and will lead to further engine damage if not repaired. Dealer inspected and diagnosed the problem. There were no vehicle warnings. It was brought to dealer because it was leaking oil and smelled of burning oil. It appears to be a common problem with Mazda Cx5s.
One of the Cylinder heads has a crack in which has cause some oil to leak in the affected area. This is not the 2.5T engine, there is a TSB out for those engines. The affected engine is the 2.5 NA engine.
First warning was the oil light came on and I became aware of a leak. When I took it to the mechanic the next day, he described a porous spot on the side of the cylinder head that had opened up and was rapidly losing oil when the engine was running. I understand that this is not a unique problem to my vehicle but is common with this model year. I am concerned that the engine will run out of oil and malfunction causing loss of control at highway speed. The car is currently scheduled for confirmation of the problem with the local Mazda dealer.
Defective sealant used on timing cover, already leaking engine oil at 85000km… also confirmed as the same engine prone to cylinder head cracking from poor casting dimensions resulting in engine oil contacting the exhaust manifold and smoking. Possible fire hazard. Engine can seize up from low oil pressure at highway speeds and lock up the wheels causing an accident. Not sure why Mazda hasn’t issued a recall for this obvious safety concern… reminds me of Hyundai/Kia engine problems and now they’ve been sued and replacing thousands of engines for free.
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?
Cylinder head was found to be cracked for a while on the vehicle. This was discovered at 117K miles but likely was cracked well before judging from the age of the oil in the engine bay. Car has been maintained well this shouldn't be happening at all this early into its life.
Burnt oil smell started being noticed in the cabin. Checked for leaks and none was found. Took the car to the dealer and it turns out the cylinder head is cracked. Dealer acknowledged this is an ongoing manufacturing issue. I contacted Mazda corporate to see if I qualify for after warranty assistance. No engine lights are on. Car has been maintained properly.
Cracked Cylinder Head. Oil leak and smoke near passenger side.
I bought this brand new in 2018 (Aug.) and I take care of this car very well. I was in the Korean Army, and I worked at the motor pool taking care of cars and trucks. Last year, I noticed my oil level decreasing that I kept refilling. I just thought it was burning some oil. Last week, I was losing lots of oil with some smoke (oil burning). I took the car to a local shop and they said "the cylinder head appears to be leaking oil from the back drivers side of the head".
I noticed a burning smell while driving. Smoke started coming through the air vents and made me light-headed. I asked my son to take a look, and he said that oil was dripping onto the exhaust and smoking, and it could have caught on fire. There were no warning lamps or any other indicators besides the smell and smoke. I could have passed out from inhaling the smoke and died, or my car could have caught on fire. I took my car to the Mazda dealer. They confirmed that my car was affected by the well-known 2018-2021 CX-5 cylinder head crack. They quoted me $4848 to fix it. When I asked if they could help me with the price, they offered me 10% off. I told them that’s unacceptable. After much back and forth with the dealer and Mazda Corporate, they dropped the total to $1470.60.
There was a burnt rubber smell coming off the vents, took to dealership and they confirmed there was an issue with the front timing cover and was replaced. Less that a week later, there was smoke coming from the hood of the car. Took back to dealership unaware if it was recurring issue but it was determined there was a NEW oil leak due to faulty cylinder head needing replacement on my car which has less than 50,000 miles. While there was no warning lights, the car was unsafe to drive in that condition.
The cylinder head cracked while waiting for a light to change at a busy intersection, causing heavy smoke to enter the vehicle through the air vents with the heater on. The smoke filled the car quickly, causing my wife and me to exit the vehicle at the very busy intersection. A local independent service center diagnosed the problem. I was unable to drive the vehicle to the manufacturer for safety reasons and smoke filling the cabin. No warning lights were displayed. This vehicle was maintained following the manufacturer's recommendations throughout its 77,000 mile life.
The engine cylinder head has a crack that has caused the engine oil to leak from the engine. This seems to be a common issue known by Mazda. The oil has saturated the right front brake and portions of the undercarriage, that will also need to be cleaned and or replaced. We had the car looked at a repair shop in Portland OR. they let us know this is a huge problem with this engine and we have not had this repaired as of this note. we will contact or dealer where we purchased the CX-5 and see about getting it replaced. This happened as my Wife was driving from California to our home in Washington. She noticed the oil light was flickering and she found a repair shop in Portland that looked at it and for that the head was cracked. Our car has 89,413 miles on it and has been maintained and does not have any other issues at this time.
Oil smell in cabin. Diagnosed by independent repair shop as hairline crack in back of cylinder head. Cylinder head replaced at 91000 miles.
We own a 2018 Mazda CX-5 which developed a cracked cylinder head after slightly over 53,000 miles. We had oil leaking in our driveway and our dealership advised us not to drive it as this would be an extreme safety issue. I was advised to contact you as this seems to be an ongoing issue with Mazda CX-5's from 2018-2021. There is a safety bulletin TSB #SA-031-21. I am hoping this will help with resolving this with Mazda costumer service.
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)
Cracked cylinder head at 75000 miles causing oil to leak, Mazda dealership called it a fire risk
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The 2018 Mazda CX-5 has 66 Engine complaints on file. Review the timeline above for detailed owner experiences.