2018 Mazda CX-5 Complaints

FUEL/PROPULSION SYSTEM — Filed 07/14/2026

Check engine light on when read it comes back with P0171 code

ENGINE — Filed 07/01/2026

The contact owns a 2018 Mazda CX-5. The contact stated that white smoke was coming from the engine compartment whenever the vehicle reached normal operating temperature. The contact stated that smoke entered the passenger’s side compartment through the air vents and was coming from underneath the hood. The contact stated that there was a burning odor coming from the engine compartment due to an oil leakage. The smoke impaired visibility while driving. The most recent failure had occurred while driving approximately 35 MPH on a city roadway. The vehicle was driven to an independent mechanic to be diagnosed, and then to the dealer for further inspection. The independent mechanic diagnosed the vehicle with a cracked cylinder head and recommended that the vehicle be taken to the dealer for additional diagnostic tests. The dealer diagnosed the cylinder head as porous and informed the contact that the cylinder head needed to be replaced. The manufacturer was notified and informed the contact that the repair would not be covered. The vehicle was not repaired. The contact stated that the failure had occurred intermittently and became more frequent and severe during hotter weather. The failure mileage was approximately 83,000.

POWER TRAIN — Filed 05/04/2026

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.

POWER TRAIN — Filed 06/06/2026

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

ENGINE — Filed 06/12/2026

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 NHTSA 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.

POWER TRAIN — Filed 05/06/2026

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.

ENGINE AND ENGINE COOLING — Filed 04/01/2026

The contact owns a 2018 Mazda CX-5. The contact stated that while driving the vehicle he could smell a burning odor, and added that he noticed a puddle of oil on his driveway. The vehicle was taken to an independent mechanic where it was diagnosed to have a cylinder crack causing the cylinder to leak oil all over the engine. The dealer was not notified of the failure. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was 104,000.

ELECTRICAL SYSTEM,UNKNOWN OR OTHER — Filed 05/01/2021

Touch Screen and/or infotainment center causing ghost touch. Available for inspection. Ghost touch (known Mazda issue) with touch screen has been changing radio stations, increasing volume to max. Will go into user settings and change guidance voice to full volume, increasing bass to full volume, fast forward songs, mute phone call feature, randomly switch from bluetooth to handset of phone. All of this is done without the driver or anyone else in the car touching anything. When this happens there is no easy fix. I cannot just stop the song, mute the volume. We have to wait for it to decide to stop and fix itself. It is a safety issue because You are driving and randomly volume goes to full blast an startles you, cannot hear what is going on around you, and hurts your ears. This is distracting and I have swerved my car because of it. Bluetooth capability is suppose to be handsfree, so if it keeps muting my call or switching to my phone, that is now a safety hazard as well. vehicle was inspected in 2021 by Mazda dealership. At that time they said the only thing they can do it remove the SIM card, and we would lose navigation. However the issue did not stop. It would cost us about $1000+ between labor and parts and inspection to get this fixed. It was addressed again in 2023 and 2025. 2025, when the infotainment system had a class action law suit but ours wouldn't be covered because its the touch screen and not the computer. No warning systems.

ENGINE — Filed 12/12/2025

I took my car to the dealership because it was leaking oil and coolant. Upon verification, I was informed that my vehicle had a cracked cylinder head. They told me that the repaired will cost me $5500. Unfortunately this is an amount that I do not have. So I reached out to the Mazda Corporate and they told me that there is no repair assistance can be provided and that I should reach out to Mazda Dealership and see if they may accept to put the cost of the repair towards the Good Will Repair. Unfortunately I haven’t been successful with that either. My Mazda Corporate case number is 00450563. This issue is created safety issue with burning engine oils and fume entering the vehicle. This is well known issue with this car model and unfortunately Mazda has made a recall on any of them. While I understand that this may cause Mazda Millions if a recall is put out, it will great to assist with the ones experiencing this issue. Any assistance regarding this matter will be truly appreciated.

POWER TRAIN,ENGINE — Filed 05/13/2026

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.