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 ↗2021 Mazda CX-5 powertrain problems
moderate Owners of the 2021 Mazda CX-5 have filed 15 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
15
Recalls
0
Avg fix
$2,500
| Model year | powertrain complaints |
|---|---|
| 2017 CX-5 | 11 |
| 2018 CX-5 | 17 |
| 2019 CX-5 | 29 |
| 2020 CX-5 | 8 |
| 2021 CX-5 (this page) | 15 |
| 2022 CX-5 | 4 |
| 2023 CX-5 | 3 |
| 2024 CX-5 | 3 |
What stands out
No new NHTSA powertrain complaint has been filed on this vehicle in over 4 years — the issue may be aging out of the active population.
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.
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 ↗Some customer's might state that they notice fluid or oil leaking/dripping on the ground when the vehicle is parked. For this concern, inspect the vehicle for any trace of a fluid or oil leak and use the following examples as a guide to determine if it is severe enough to require a repair, or just to clean the area and monitor it at the next service. Examples of residue or seepage that may not be considered a leak and that may not require repair based on splash shield inspection.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
2021 CX-5 owners across this complaint cluster describe a powertrain that consumes oil at roughly one quart per 3,000–4,500 miles of normal driving, triggering low-oil warnings well before scheduled service intervals. No external leaks appear, yet black soot lines the inside of tailpipes and oil odor surfaces during highway driving. Mazda has issued Technical Service Bulletins covering specific VIN ranges that identify a manufacturing defect allowing oil to enter the combustion chamber—dealers acknowledge these are "known" vehicles—yet warranty coverage is routinely denied. Owners who top off oil after low-oil warnings are told they've voided the warranty by adding oil themselves.
Beyond oil consumption, owners report a rear differential that seized at 24,000 miles, a cylinder deactivation system that causes violent shaking and stuttering, rough hunting behavior at low speeds that Mazda's own dealership confirms is a widespread Skyactive issue, coolant leaks paired with running-hot warnings, and recurring oil leaks from timing covers and gaskets despite multiple warranty repairs. One early vehicle exhibited total electrical failure at 1,500 miles with battery drain that dealerships couldn't diagnose. Mazda has not issued recalls for most of these defects and continues selling CX-5s with known issues unresolved.
Same Mazda CX-5 powertrain reports on nearby years: 2018 · 2019
Failure modes owners describe
Excessive oil consumption
Engine consumes oil rapidly between scheduled oil changes without visible external leaks, requiring owners to add oil frequently. Owners report consuming approximately one quart per 3,000–4,500 miles of normal driving on turbo and naturally-aspirated engines. Mazda has issued TSBs covering specific VIN ranges, and dealers have acknowledged the issue is known but offered no repair under warranty, instead suggesting oil consumption testing at owner expense.
When: Starts appearing within first 5,000–7,000 miles; persists throughout ownership.
Symptoms owners cite: Low oil level warning lights illuminated between oil change intervals; Manual dipstick checks reveal oil 0.5–1.0 quart low; No visible external oil leaks on driveway or parking areas; Black soot visible inside tailpipes; Slight whitish vapor on cold startup; Odor of burning oil during highway driving (some cases)
Repairs/costs cited: Dealerships have performed multiple oil changes but offered no root-cause fix. One owner reports being told valve stem seal problems are addressed in TSBs. Mazda dealerships refused warranty coverage when owners added oil after low-oil warnings, claiming oil was added by owner.
Recalls/TSBs owners mention: Technical Service Bulletins (TSBs) issued covering specific VIN ranges indicating manufacturing defect allowing oil to leak into combustion chamber. Dealers informed owners the vehicles are 'known to consume oil.' Mazda has not issued recalls and has declined to warranty repairs. Mazda acknowledged awareness of the problem in at least one case but stated they are not fixing it.
Severe cooling system failure (cracked head or blown gasket)
Engine coolant visible in engine bay shortly after oil service, accompanied by oil consumption and running-hot warnings. One owner reports Mazda acknowledged being aware of the problem but continued selling cars with the defect unresolved.
When: Reported in 2023 vehicle; detected within days of oil service.
Symptoms owners cite: Oil light illuminated shortly after oil change; Engine running hot warning; Visible coolant in engine compartment; High oil consumption immediately preceding failure
Repairs/costs cited: Requires head or gasket repair. Owner states Mazda is aware of the issue.
Recalls/TSBs owners mention: Mazda reportedly told owner they are aware of the problem but have not issued a fix or recall.
Rear differential failure
Rear differential required replacement at only 24,000 miles. No warning lamps appeared; owner detected via unusual noise and escalated to dealer diagnosis. Reported as a known common issue on forums for this make/model.
When: 24,000 miles
Symptoms owners cite: Unusual noise from rear differential; No warning lamps
Repairs/costs cited: Requires rear differential replacement. Dealer confirmed defect and contacted Mazda for warranty approval.
Recalls/TSBs owners mention: Covered under warranty per dealer contact.
Cylinder deactivation system malfunction
When the cylinder deactivation system engages, the engine shakes and stutters, creating vibration described as driving over cobblestones. Sometimes subtle, sometimes severe enough that car feels like it will stall. One owner notes it mirrors a 2018–2019 recall issue.
When: Ongoing for several months at time of complaint.
Symptoms owners cite: Engine shaking and stuttering when cylinder deactivation triggers; Vibration sensation described as 'driving over cobblestones'; Occasional feeling that car might stall
Recalls/TSBs owners mention: Owner notes this is the same issue as a 2018–2019 recall, suggesting Mazda was aware.
Rough idle and transmission hunting at low speeds
Vehicle exhibits rough driving feel at speeds under 30 mph with jerky or hunting behavior. Dealership confirmed this is a common issue on Skyactive-engined Mazdas. Suggested software update as only possible remedy.
When: Present with less than 13,000 miles.
Symptoms owners cite: Rough driving feel at low speeds (under 30 mph); Jumping sensation; unclear transmission gear selection; Noticeable in residential driving
Repairs/costs cited: Dealership suggested possible computer software update as only available option.
Recalls/TSBs owners mention: Dealership acknowledged this is a known common issue but offered no fix.
Oil leak from timing cover and gaskets
Multiple oil seals and gaskets leak after one or more warranty repairs. One owner reports multiple repair attempts (timing cover and gasket replaced at least twice) without resolving the leak. Recurrence triggers oil-related error messages and heavy burning smell.
When: One case reported at 70,000 miles; another case had multiple repairs with recurrent leaks.
Symptoms owners cite: Visible oil leaking; Burning smell from engine area; Oil-related error messages on dashboard
Repairs/costs cited: Timing cover and gasket replaced twice in one case without resolving leak. One owner at 70,000 miles reports multiple seals leaking.
Recalls/TSBs owners mention: Warranty repairs performed but leaks recur. Owner characterizes as known defect; unclear if Mazda acknowledges.
Electrical system failure and battery drain
Complete loss of all electrical systems and power on a 2021 CX-5 with only 1,500 miles after one day of non-use. Battery voltage dropped to 2.5 volts overnight despite previously testing normal. After external charging and restart, faint buzzing audible from engine compartment; subsequent testing showed charging system output normal (14+ volts) but voltage dropped to 12.1 volts immediately after engine shutdown.
When: At 1,500 miles; occurred after one day of vehicle sitting unused.
Symptoms owners cite: Complete loss of electrical power and all systems; No warning lights or prior indication; Battery voltage dropped to 2.5 volts overnight; Faint buzzing sound from engine compartment after restart
Repairs/costs cited: High-quality battery charger restored function. Dealer tested battery after incident and cleared it as 'ok'.
Recalls/TSBs owners mention: Dealer service found no defect; returned vehicle to owner. Charging system output tested normal but root cause of overnight drain not identified.
Synthesized from 15 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 4 most recent
Bought the car brand new in May 2021, did a first oil change at around 4K miles due to the fact the car uses conventional 5w-30 oil and not synthetic oil. At around 7k miles the low oil engine light came on. Checked the dipstick and it was low. Added a quart of oil to hold me over until the next available appointment. Dealer could not find any leaks, they completed a oil change again. I went in…
When I reached 7000 miles on my car the low oil light came one. I immediately drove it to the dealership - ending a vacation early as I thought something was seriously wrong with the car. I got to dealership and they blamed me for getting an oil change at a competitor and not putting in enough oil. They then changed the oil and again at 12000 the low oil light came on. There seems to be…
Low oil level between oil change cycles with over 1,000 miles remaining before oil change is required. This has happened between both oil changes so far and I have to add oil myself to ensure oil level isn’t low. The oil consumption seems extremely high and is concerning that at only 12,000 miles I’ve had this problem happen twice.
Engine developed a major oil leak at 70,000 miles, with multiple seals leaking. This appears to be a known defect with these vehicles and owners should not be bearing the cost for repairs.
Had powertrain trouble with your 2021 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 2021 Mazda CX-5?
It's a documented issue but not catastrophic. 15 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/2021/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.