2018 Mazda CX-5 engine problems

“My 2018 Mazda CX-5 Touring (2.5L non-turbo engine with cylinder deactivation) developed a burning oil smell that steadily worsened over several days. On XXX, at about 61,300 miles, I saw smoke coming from the engine compartment after driving. The engine had not overheated, and the car was regularly maintained. On XXX, an independent repair shop (A&M Auto Repair, [XXX] a large active oil leak. After steam cleaning the engine and removing the exhaust manifold, they found engine oil leaking from a hairline crack in the cylinder head, directly onto the hot exhaust manifold. The engine was also about one quart low on oil. The shop recommended replacing the cylinder head assembly, at a cost of about $5,700 before tax. Oil leaking onto the exhaust manifold is a fire hazard, and the smoke could reduce visibility for other drivers. Many other owners of 2018–2020 CX-5s with this engine have reported the same cracked cylinder head failure. I contacted Mazda Customer Experience (case number XXX) to request assistance. Mazda declined because the repair was diagnosed and performed by an independent shop rather than a Mazda dealer. I'm submitting this complaint so NHTSA can…”

“2.5L Skyactive engine - burning smell accompanied by blue smoke from engine compartment. Yes, available for review on request. Unknown source of smoke and burning smell may be a potential complete engine damage risk. Yes, Mazda dealer confirmed leaking engine oil. No watling lamps / lights / telltales on cluster.”

“Cracked cylinder head- factory defect, causing oil to leak onto exhaust manifold. Smoke fills engine bay and cab through air vents, very high concern of engine bay fire. 2018 Mazda cx5 non turbo 2.5 sky active engine. Mazda knows of this defect and will not proved remedy.”

“2018 Mazda CX-5 2.5L NA Engine Cracked cylinder head and blown head gasket with leaking oil onto exhaust manifold resulting in white smoke & burning oil smell. No engine light. Issue confirmed by dealer and independent shop. Commonly reported issue amongst 2018-2021 Mazda CX-5 owners either naturally aspirated engines.”

“The contact owns a 2018 Mazda CX-5. The contact stated that while driving at various speeds, the vehicle was leaking engine oil, and there was white smoke coming from underneath the hood. The contact stated that upon further inspection, there was a puddle of engine oil on the ground while the vehicle was idling. No warning light was illuminated. The vehicle was towed to a local dealer, where it was diagnosed with a cracked cylinder head. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 183,540.”

“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…”