This bulletin supersedes the previously issued bulletin(s) listed below. The changes are noted in Red. 01-008/23 06/05/23 Some vehicles may exhibit rattling noises from the engine compartment and oil leakage from the drive belt auto tensioner. This may be caused by insufficient sealing at the drive belt auto tensioner damper when the auto tensioner fully operates under both high ambient temperature and high load conditions. To eliminate this concern, the shape of the drive belt auto tensioner damper has been changed. REPAIR PROCEDURE If the tensioner is found to be "No Good" after completing the Drive Belt Auto Tensioner Inspection, replace it with a modified part according to the instructio
full bulletin at NHTSA ↗2018 Mazda CX-5 powertrain problems
moderate Owners of the 2018 Mazda CX-5 have filed 17 NHTSA complaints about the powertrain at roughly $2,500 to repair (U.S. federal records, as of July 2026). Source: NHTSA Office of Defects Investigation. See powertrain across all vehicles →
Complaints
17
Recalls
0
Avg fix
$2,500
| Model year | powertrain complaints |
|---|---|
| 2014 CX-5 | 49 |
| 2015 CX-5 | 19 |
| 2016 CX-5 | 49 |
| 2017 CX-5 | 11 |
| 2018 CX-5 (this page) | 17 |
| 2019 CX-5 | 29 |
| 2020 CX-5 | 8 |
| 2021 CX-5 | 15 |
| 2022 CX-5 | 4 |
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering powertrain 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 ↗Some vehicles may display some (or all) of the following symptoms: • Check engine light on with DTC P061B • Light increase in engine rpms during acceleration • Transmission will not shift past 4th gear • Various U codes (U0401 ABS, U0401, U0415 FSC, U0301, U0316 SBS/MRCC, U0442 TCM) may be set
full bulletin at NHTSA ↗When inspected, the differential or PTO oil is dark or black. This is considered normal and NO repair should be performed. During production, differential ring and pinion gears receive a manganese phosphate coating (commonly referred to as black oxide). This coating forms a porous, oil-retentive surface that improves boundary lubrication and reduces adhesive wear during initial contact cycles. Designed as a sacrificial layer, it is gradually removed under load throughout the break-in process. As a result, after the first few hundred miles, or at the initial gear oil service interval, the lubricant may appear darkened by the worn-off coating. It will contain trace ferrous particles from the n
full bulletin at NHTSA ↗Noise, Vibration, and Harshness (NVH) Diagnostic Guidelines Diagnostic Guidelines When diagnosing NVH concerns, it is essential to first classify the issue into one of three primary categories: Noise, Vibration, or Harshness. Many customer complaints may involve overlapping symptoms, such as both noise and vibration, so identifying the dominant characteristic is critical. Once the primary symptom is determined, follow the appropriate diagnostic path. For example, if a concern includes both noise and vibration but is related to vehicle speed, the vibration diagnostic path should be followed. When considering component replacement during the diagnostic process, it is best practice to start wit
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Owners describe a clear pattern: burning oil smell inside the cabin, white or blue smoke from the engine, and oil pooling underneath or spraying onto hot engine parts. The damage appears as cracks in the cylinder head allowing pressurized oil to escape. Most failures cluster between 22k and 62.5k miles. One vehicle showed the defect at 22k miles on a well-maintained example with zero accidents; another at 25k, another at 51k, another at 52k, and another at 58k.
Notably, no dashboard warning lights or temperature warnings appear before the failure. Owners smell the burning oil, see smoke, and find the leak—then get the diagnosis. One shop reports finding the cracked head after initially replacing the timing lock due to white smoke symptoms.
The oil spray hits the catalytic converter and exhaust manifold—components hot enough to ignite leaking oil, creating a fire risk. One dealership explicitly flagged the vehicle as unsafe to operate. Repairs run $5100 to $7500 for cylinder head replacement with parts kit. Most owners report being out of warranty by 3–12 months when the problem surfaces, though one vehicle was still under the 60k mileage cap. One owner notes a TSB exists; another states Mazda offered partial financial consideration but no good-will recall program.
Same Mazda CX-5 powertrain reports on nearby years: 2015 · 2016 · 2017 · 2019 · 2021
Failure modes owners describe
Cracked cylinder head with oil leakage
Cylinder head develops cracks on the exhaust side or elsewhere, allowing pressurized oil to spray or drip from the engine block. Oil accumulates on the exhaust manifold, catalytic converter, and undercarriage. Owners report discovering the cracks at 22k to 62.5k miles, typically before or shortly after warranty expiration.
When: 22k–62.5k miles; several owners note the vehicle is 3–12 months out of powertrain warranty
Symptoms owners cite: Strong burning oil smell inside cabin and under hood; Light blue or white smoke from engine bay or air vents; Oil leaking onto driveway or undercarriage; Visible smoke or mist through air vents; No warning lights or dashboard indicators prior to failure
Codes mentioned: SA-037/23
Repairs/costs cited: Cylinder head replacement with parts kit; quoted costs range from $5100 to $7500. Mazda dealerships performed the work. One owner reported partial financial consideration from Mazda; one used-car dealer split repair cost 50/50.
Recalls/TSBs owners mention: TSB exists for the issue per one owner claim. One owner states Mazda offered partial financial consideration but refused good-will warranty coverage; no recall has been issued as of complaint dates.
Fire hazard and safety risk from leaking oil on hot surfaces
Oil spraying onto the catalytic converter and exhaust manifold creates a fire hazard due to the extreme heat in those areas. One owner reports the dealership deemed the vehicle unsafe to operate once the leak was diagnosed.
When: Develops during normal operation; detected when oil smell or smoke appears
Symptoms owners cite: Burning smell intensifying; Visible smoke from under hood or through vents; Oil soaked on undercarriage and hot engine components
Repairs/costs cited: No repair attempts documented; vehicle pulled from service pending cylinder head replacement.
Transmission/drivability issue during acceleration
Single complaint of improper gear shifting during acceleration with engine rpm rising but vehicle not accelerating proportionally. Occurred at 25k miles with no warning lights. Separate from the cylinder head failures but included in the powertrain cluster.
When: 25k miles
Symptoms owners cite: RPM revs but vehicle does not accelerate; Occurs intermittently during acceleration; No warning lights or messages
Synthesized from 17 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 2 most recent
The cylinder head on my 2018 Mazda CX-5 developed cracks on the exhaust side, leading to significant oil leakage onto the exhaust manifold. This has caused engine damage and safety concerns. The vehicle is currently at a Mazda dealership, where the issue has been inspected and documented. The component is available for further inspection upon request. The oil leaking onto the exhaust manifold…
This car has a confirmed cracked cylinder head and is leaking oil. This is a known issue and there is a TSB out for it. It happened at $62500 miles and is just outside of the warranty. This has happened to several of these cars. Mazda is not doing "good will" to repair them and there is not yet a recall which there should be. The car suddenly started leaking oil and smoking/burning. It is…
Had powertrain 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 powertrain problem on the 2018 Mazda CX-5?
It's a documented issue but not catastrophic. 17 complaints have been filed. Repairs average $2,500 and most owners catch it before it causes a breakdown.
At what mileage does the powertrain typically fail?
Mileage data is limited for this issue. Owners report failures across a wide range, suggesting cause is more about driving conditions and maintenance than mileage alone.
What does it cost to fix?
Independent shops typically charge around $2,500 for powertrain 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 powertrain?
No active recalls currently cover powertrain 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.