Mazda · Known Issues
2021 Mazda CX-5 Problems: 15 Known Issues
2021 model year · 10,410+ owner reports · Updated September 2026
2021 · All trims · All engines
Choose the year and equipment for your written issues and visual request.
2021 model year · 10,410+ owner reports · Updated September 2026
2021 · All trims · All engines
Choose the year and equipment for your written issues and visual request.
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According to Au7o's analysis of 10,410+ owner reports, the 2021 Mazda CX-5 has 15 documented known issues, with 3 rated critical. The most serious are Defective Fuel Pump (Denso Recall), Excessive Engine Oil Consumption and SKYACTIV-D 2.2 Diesel Engine Oil Dilution from Interrupted DPF Regeneration ($120-$4,500 repair). The most commonly reported issue is Defective Fuel Pump (Denso Recall) with 3,200 owner reports. Across all issues with published estimates, repair costs range from $100 to $4,500. DIY maintenance guides at au7o.io.
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According to Au7o's analysis of 10,410+ owner reports, the 2021 Mazda CX-5 has 15 documented issues. The most frequently reported are: Defective Fuel Pump (Denso Recall), Excessive Engine Oil Consumption, SKYACTIV-D 2.2 Diesel Engine Oil Dilution from Interrupted DPF Regeneration. Of these, 3 are rated critical and should be addressed promptly.
The 2021 Mazda CX-5 has 15 known issues documented across 10,410+ owner reports. 3 issues are rated critical: Defective Fuel Pump (Denso Recall) and Excessive Engine Oil Consumption and SKYACTIV-D 2.2 Diesel Engine Oil Dilution from Interrupted DPF Regeneration. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.
Repair costs for known Mazda CX-5 issues range from $0 to $4,500, depending on the specific problem and whether you choose DIY or professional repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.
Low-pressure fuel pump impellers can deform, causing pump failure and engine stalling without warning. Part of massive global recall affecting 19+ million vehicles across multiple manufacturers. Severity: high.
Defective valve stem seals allow oil to leak into combustion chambers, causing excessive oil consumption and potential catastrophic engine failure if oil levels drop critically low. Issue primarily affects 2013-2014 models with resurgence in 2021-2022. Severity: high.
Content on this page was compiled with AI assistance using NHTSA complaints, TSBs, owner reports, and public automotive data. While we strive for accuracy, this information may contain errors. Always verify repair procedures and specifications with your vehicle's service manual or a qualified mechanic.
The 2.2 SKYACTIV-D uses post-injection of diesel into the cylinder to raise exhaust temperature for diesel particulate filter regeneration. Fuel that is not burned washes past the rings into the sump. If the engine is shut off mid-regeneration - the normal outcome of short urban… Repairs typically run $120-$4,500. Severity: high.
Direct-injection Skyactiv engines accumulate carbon deposits on intake valves due to oil vapors from the PCV system. Without port injection to clean valves, carbon can fuse to valve surfaces over time, typically appearing around 65,000+ miles. Severity: medium.
The Connectivity Master Unit (CMU) fails, causing the infotainment screen to go black, flicker, freeze, or loop repeatedly. Often caused by corrupted firmware, faulty Nav SD card contacts, or failing internal memory. Severity: medium.
Interior door panels rust due to improper drainage design allowing water accumulation. Some colors (Soul Red, Machine Grey) have thin paint causing premature rust bubbling on roof and body panels. Severity: medium.
Wheel bearings fail prematurely due to impact damage (potholes, curbs), contamination from water/salt/grit, or manufacturing defects. Common issue across all model years. Severity: medium.
The six-speed FW6A-EL automatic in the CX-5 locks its torque converter clutch very early and holds it locked across a wide range to chase fuel economy. That aggressive lock-up strategy wears the lock-up clutch lining, and the resulting iron powder contaminates the ATF. Owners rep… Repairs typically run $1,200-$3,200. Severity: medium.
On sunroof-equipped CX-5s the front sunroof drain hoses work loose from their drain-tray nipples behind the A-pillar trim, or the tubes clog with organic debris. Because nothing visibly leaks at the headliner, water tracks down inside the pillar and body cavity and pools under th… Repairs typically run $100-$600. Severity: medium.
The CX-5's Smart City Brake Support uses a laser/infrared sensor behind the windshield glass on early cars, plus a grille-mounted radar and forward camera on later i-ACTIVSENSE builds. Two distinct failure patterns are documented. First, repeated 'Smart City Brake Support malfunc… Repairs typically run $0-$1,400. Severity: medium.
A batch of 2021 model-year 2.5T engines left the factory with defective exhaust valve stem seals. Oil slips past the worn seals during the intake stroke and is burned in the chamber, so owners see the low-oil warning surprisingly early after an oil change (often 3,000-5,000 miles… Repairs typically run $0-$2,000. Severity: medium.
Second-generation KF CX-5 owners report a distinct chirp or squeak from the transaxle during the 3-4 upshift, most audible at light to moderate throttle once the transmission is at operating temperature. It is not the lock-up shudder felt through the seat - it is an audible chirp… Repairs typically run $0-$1,800. Severity: low.
CX-5 owners report unusually thin paint film and a fragile clear coat that chips on the hood, front fascia, A-pillars and mirror caps far earlier than the segment norm. Complaints intensify from the 2016.5 refresh forward and are heaviest on the Soul Red Crystal three-stage finis… Repairs typically run $400-$2,500. Severity: low.
CX-5 models with i-stop (idle stop) use a specific AGM/EFB battery and a battery-management system that monitors charge state to decide whether to allow auto stop-start. The factory battery is undersized (around 480 CCA new) and degrades early; as it weakens, owners get an i-stop… Repairs typically run $200-$350. Severity: low.
SKYACTIV-G engines are widely reported to develop a slow oil weep at the timing chain cover, where the factory RTV/silicone sealant is applied inconsistently at the seam. Owners find oily film at the front-lower timing-cover area, often discovered at oil-change inspections. Separ… Repairs typically run $400-$1,400. Severity: low.