This SA supersedes the previously issued SA(s) listed below. The changes are noted in Red. SA-061/25 12/17/25 DESCRIPTION If you encounter any type of electrical concern (e.g, dead battery, engine no start, DTC(s) stored...), interview the customer before proceeding with normal MGSS diagnosis by asking if any aftermarket devices have been installed. Aftermarket devices may be the cause of the electrical concern. Below are a few examples of unusual electrical concerns caused by aftermarket devices. Examples: 1. Devices connected to the DLC-2 (battery discharge/DTC stored) 2. Devices plugged into the 12V outlet 3. GPS tracking device (engine no start/battery discharge) 4. Dash cam (DTC stored)
full bulletin at NHTSA ↗2018 Mazda CX-5 engine problems
moderate Owners of the 2018 Mazda CX-5 have filed 85 NHTSA complaints about the engine at roughly $3,100 to repair (U.S. federal records, as of July 2026). Source: NHTSA Office of Defects Investigation. See engine across all vehicles →
Complaints
85
Recalls
0
Avg fix
$3,100
| Model year | engine complaints |
|---|---|
| 2014 CX-5 | 12 |
| 2015 CX-5 | 7 |
| 2016 CX-5 | 21 |
| 2017 CX-5 | 9 |
| 2018 CX-5 (this page) | 85 |
| 2019 CX-5 | 100 |
| 2020 CX-5 | 12 |
| 2021 CX-5 | 62 |
| 2022 CX-5 | 6 |
When does it fail?
Of the 85 engine complaints filed for the 2018 Mazda CX-5, here's the actual mileage breakdown — failures cluster heaviest at 50,000-75,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
Owners have filed 85 engine complaints with NHTSA against this vehicle, but no formal recall covers the issue — the federal record reflects what manufacturers have admitted, not everything owners are reporting.
Among the 12 model years of Mazda CX-5 in our records for engine problems, this one ranks #2 by owner-complaint volume.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering engine on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
This Service Alert supersedes the previously issued SA listed below: The changes are noted in Red. SA-011/24 02/12/24, 06/06/24, 07/29/24 DESCRIPTION Mazda has developed factory recommended scheduled maintenance services that support all major vehicle systems. Mazda recommends dealers follow the scheduled maintenance tables as cited in the vehicle-specific workshop manual or owner's manual. Services performed outside of Mazda's factory scheduled maintenance are not recommended. These services are unnecessary and create unneeded expenses for your customers. SCHEDULED MAINTENANCE Refer to the applicable Workshop Manual or Owner's Manual for vehicle -specific manufacturer scheduled maintenance.
full bulletin at NHTSA ↗This Service Alert supersedes the previously issued M-Tip(s) listed below. The changes are noted in Red text. MT-002/19 09/30/19 and 12/19/19 DESCRIPTION If an engine assembly is replaced after a catastrophic internal mechanical failure, clean the intake manifold internally before installing a replacement engine assembly. If the intake manifold is not cleaned properly, the replacement engine may fail prematurely. Metallic debris from the old engine (with catastrophic internal mechanical failure) may rest inside the intake manifold. When the new engine assembly is installed, debris in the intake manifold will be ingested into the new engine and cause internal damage. Clean the intake manifold
full bulletin at NHTSA ↗This Service Alert supersedes the previously issued SA(s) and TSB(s) listed below: The changes are noted in Red. SA-035/24 05/31/24 DESCRIPTION There is a concern that some water pumps are being replaced that are not faulty, due to signs of a very small coolant leak from the bleed hole. This Service Alert is to inform you about the water pump sealing mechanism and the criteria if replacement is necessary or not. A mechanical seal (A) is used for the water pump. This mechanical seal can seal coolant (B) by sliding a mating ring (C) against a seal ring (D). When the sliding surface temperature of the mechanical seal is more than 248 °F (120 °C) while driving, a small amount of steam (E) is lea
full bulletin at NHTSA ↗Subject: TSB 01-001/26 Warranty and Parts Kit Update INCLUDES: Warranty Extension Program - Special Service Program (SSP) D8 Check Engine Light ON with DTC P0126:00, 2018-2025 CX-5, 2019-2023 Mazda3, 2019-2022 CX-3, 2018-2021 Mazda6, 2020-2023 CX-30 Dear Mazda Dealer Colleagues, Mazda Motor Corporation has made a change regarding related parts to TSB 01-001/26 which also impacts Warranty Extension Special Service Program (SSPD8). Parts Ordering and Warranty Claims: Effective March 5, 2026 only the related parts kit PYY2-15-SAY can be ordered and claimed for any repair. The two separate parts PYFB-15-169 and PE13-15-296 can no longer be claimed with repaired dates of March 5, 2026 and later.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Owners of 2018 Mazda CX-5 models report a recurring cracked cylinder head defect affecting the 2.5L SKYACTIV-G engine. The failure typically occurs between 25,000 and 119,000 miles with no prior warning lights or symptoms—most cite only a burning oil smell, visible smoke from under the hood or entering the cabin, and oil puddles appearing suddenly on driveways or under the vehicle. When inspected, dealerships consistently confirm oil leaking from the cylinder head onto the exhaust manifold.
The pattern is unmistakable across these narratives. Owners repeatedly identify Mazda Technical Service Bulletin SA-031-21 (issued May 2021) and Service Action SA-073-24 as evidence Mazda knew of the defect, yet the company has inconsistently applied warranty coverage and repair assistance. Some owners report Mazda covered 100% of repairs or offered extended warranties; others were denied coverage despite being within mileage or age limits. Repair costs cited range from $4,800 to over $9,500.
Owners describe a serious fire hazard: oil dripping onto hot exhaust manifolds creates smoke and burning oil fumes that enter cabins, sometimes causing dizziness or requiring immediate vehicle abandonment. Several note the aluminum cylinder head is abnormally thin (2mm vs. 5–7mm on comparable engines). A few report low oil pressure warnings appearing shortly before failure, and one describes unexpected engine shutdown at highway speed post-repair. Mazda's internal acknowledgment of the issue as widespread, combined with the narrow scope of recalls and extended warranties (covering only turbocharged or certain model years), fuels owner frustration.
Same Mazda CX-5 engine reports on nearby years: 2016 · 2019 · 2020 · 2021
Failure modes owners describe
Cracked Cylinder Head
Aluminum cylinder head develops cracks or porous casting defects, allowing engine oil to leak internally and externally onto the exhaust manifold. Owners consistently cite this as a known manufacturing defect in the 2.5L SKYACTIV-G engine.
When: 25,000 to 119,000 miles; commonly 31,000–90,000 miles reported; no correlation to age or mileage alone
Symptoms owners cite: Burning oil smell in cabin and engine compartment; Visible smoke from under hood or entering cabin via AC/vents; Oil pooling on driveway or underneath vehicle; Strong odor of burnt rubber or petroleum fumes; Low oil pressure warning light (late indicator); No check engine light or other dashboard warning until late-stage failure
Codes mentioned: SA-031-21 (Technical Service Bulletin), SA-073-24 (Service Action)
Repairs/costs cited: Cylinder head replacement or engine replacement; repair costs cited as $4,800–$9,500; some owners report dealership gasket replacements initially misdiagnosed the issue and replacement required cylinder head work instead
Recalls/TSBs owners mention: Mazda issued TSB SA-031-21 (May 2021) for 2018–2019 models, later extended to 2023+ models. Coverage varies inconsistently: some owners report Mazda covered 100% or offered extended warranties (e.g., CSP11 for some 2019 models); most out-of-warranty owners denied coverage despite acknowledged defect. Mazda declined assistance for vehicles past 60K miles or 5-year powertrain warranty, regardless of actual mileage at failure. Some owners reported Mazda offered 10–37% cost assistance after escalation to corporate.
Oil Leak from Cylinder Head or Timing Cover
Secondary leaks from timing cover or defective sealant in front cover cause oil dripping and burning; sometimes develops after dealership gasket replacement attempts.
When: 85,000+ km; can appear shortly after unrelated service
Symptoms owners cite: Oil dripping onto driveway or garage floor; Burning oil smell; Smoke from engine; Low oil indicator light
Repairs/costs cited: Timing cover replacement quoted at $2,500 initially (for gasket); full cylinder head replacement required $4,500+
Engine Ticking Noise (Hydraulic Lash Adjuster Issue)
Ticking noise originates from inside the engine, reported by multiple owners as a separate or concurrent issue. Owners suspect Hydraulic Lash Adjusters (HLA) but note no diagnostic codes appear.
When: Mileage variable; owners report noticing after detecting other issues or during independent research
Symptoms owners cite: Persistent ticking or valve train noise from inside engine; No check engine codes detected; Owners describe it as identical to noise in forum posts from other CX-5 owners
Repairs/costs cited: One owner reports mechanic said engine must be disassembled for diagnosis; no repair costs cited as work not yet performed
Engine Shutdown / Loss of Power at Highway Speed
Two distinct incidents: one vehicle shut down completely while in motion (electrical systems remained); another experienced misfires, check engine light flashing, radar malfunction, and complete power loss at highway speeds, repeatable at acceleration.
When: One reported at unspecified mileage shortly after PCM and fuel-system recalls; another at highway speed during driving
Symptoms owners cite: Complete loss of engine propulsion without warning; Electrical systems remain functional (radio, heat, electronics); Check engine light flashes (second incident); SmartCity Brake System and Radar warnings appear; Vehicle coasts; lights and brakes still work; Misfiring, check engine code migrating between cylinders 3 and 4; Repeatable when accelerating to highway speeds
Codes mentioned: Check engine light (code specifics not provided), SmartCity Brake System Malfunction warning, Radar Malfunction warning
Repairs/costs cited: First incident: no diagnostic completed; second incident: not yet repaired as of complaint filing
Brake System Malfunction Post-Repair
Following major cylinder head / engine repair, owner reports unexpected brake warnings and unexpected braking while driving, creating risk of rear-end collision.
When: Few days after engine repair at 75,000 miles
Symptoms owners cite: Brake system warning lights; Unexpected braking while driving (nearly caused rear-end collision); Vehicle system malfunctions appearing shortly post-repair
Repairs/costs cited: Major engine repair completed; dealership inspected but root cause of new brake issue unexplained
Synthesized from 85 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 18 most recent
Cracked cylinder head due to defect in the casting process. Oil leaking thru the crack landing on the exhaust manifold causing an odor and possibly toxic fumes in the cabin of the vehicle.
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.
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…
Crack Cylinder Head less than 50,000 miles
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…
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…
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…
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.
Hydraulic lifters keep having issues
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 engine trouble with your 2018 Mazda CX-5?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the engine problem on the 2018 Mazda CX-5?
It's a documented issue but not catastrophic. 85 complaints have been filed. Repairs average $3,100 and most owners catch it before it causes a breakdown.
At what mileage does the engine typically fail?
Based on the 85 complaints filed, engine issues most often appear around 82,000 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to engine?
No active recalls currently cover engine issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2018/Mazda/CX-5.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.