Bought this car in May 2026 with about 15k miles. Today November 6th 2026 at the dealership I was told that the belt tensioner was loose. Searching online it looks like a widely known issue that Mazda apparently has known but has not fixed. This should not happen on a car with 18k miles. If the belt fails while driving it can put everyone in the car and around it in physical danger. Please look into this. In all fairness CardinaleWay Mazda is fixing the issue under warrenty, but the bigger issue is safety.
Engine & cooling
Mazda CX-50 Engine problems by year
14 complaints filed with NHTSA about the Mazda CX-50's engine & cooling. Stalling, loss of power, oil consumption, overheating, head gaskets, timing chains and engine failure.
Engine complaints by model year
Latest CX-50 engine complaints
The vehicle experienced a total electrical blackout, refused to start for hours, and threw a U0115 (Lost Communication with ECM/PCM B) network code. I consider this an extreme safety hazard because a communication failure of this specific kind risks causing an unexpected engine shutdown or total loss of motive power while driving. This car only has 8,500 miles on it, so a problem this severe this early is extremely concerning!
I own a brand-new 2026 Mazda CX-50 Hybrid that is currently under the manufacturer's warranty. I am reporting an intermittent failure of the vehicle to respond normally to a selected driving direction. During the first incident on August 28, 2026, I had shifted the vehicle into Reverse. The vehicle indicated that Reverse was selected, but when I pressed the accelerator, the vehicle did not move or respond as expected. I attempted to change the selected driving direction, but the vehicle was not responding...
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normally to the shift commands.l, again responding as if it were in neutral. I was unable to get the vehicle to operate normally until I turned the vehicle completely off, waited, and restarted it. After restarting, the vehicle began responding normally and was able to engage and move as expected. I captured the first incident on video. The video shows the vehicle's behavior during the event. The same issue occurred again on Sept21, 2026. Again, the vehicle did not respond normally to the selected driving direction and accelerator input. I had to turn the vehicle off and restart it before normal operation returned. This concerns me because the vehicle is intermittently failing to respond and move as commanded. The fact that normal operation returns after the vehicle is shut off and restarted makes the problem particularly difficult to reproduce, but it has now occurred more than once. I have reported the issue to my Mazda dealership and am requesting that the vehicle be inspected and diagnosed under warranty. I have also identified other NHTSA owner complaints involving 2025 and 2026 Mazda CX-50/CX-50 Hybrid vehicles describing similar symptoms, including failure to engage a selected direction, unexpected movement in the opposite direction, lack of vehicle response, and normal operation returning after the vehicle is shut off and restarted.
On multiple occasions the vehicle has not acceleratedfrom a stop while pushing the accelerator pedal. Have noticed this is usually on warmer days, with AC on half to full, within 3 minutes, and within 1 mile from leaving work for the day after car has sat parked. I am worried this will get worse and cause a potentially dangerous situation when turning left against traffic and the car doesn't accelerate.
"My 2025 Mazda CX-50 began overheating while still under the factory warranty. During one incident, the engine lost coolant and overheated. I immediately shut the engine off to prevent damage. The vehicle continues to overheat, and the air conditioning only cools properly while the vehicle is moving. When stopped or idling, the A/C stops cooling. I have reported the issue to my Mazda dealer and opened Mazda Customer Experience Case Number 00473077. The problem remains unresolved despite multiple attempts to obtain...
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assistance. I am concerned this condition presents a safety risk." "The vehicle has been inspected by an authorized Mazda dealership on two separate occasions. The dealership kept the vehicle for several days during these inspections but reported that it could not reproduce or identify the cause of the overheating. Despite these inspections, the overheating condition and the air conditioning issue continue. During one of the service visits, I also discovered scratches to the vehicle's exterior that were not present before it was left with the dealership."
At approximately 2,900 miles, during the first oil change/service, the factory-installed spin-on oil filter could not be removed normally. The oil filter required approximately one hour of removal effort and would not spin off in a normal manner. When the filter was finally removed, the oil filter threaded adapter/union came out of the engine-side oil filter housing while still seized inside the oil filter. The adapter threads showed visible damage, including flattened, galled, and torn thread areas. The oil filter...
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was seized tightly enough to the adapter that the oil filter had to be cut away from the adapter to separate the parts. The adapter was removed from the filter without adding further damage. The damaged adapter threads were cleaned/chased only as a temporary repair because the vehicle was needed for work and parts were not immediately available over the weekend. A new correct replacement oil filter was test-fitted to the adapter. It threaded fully onto the adapter by hand but had slight binding in the previously damaged thread area. The filter was installed, the engine was started, and the assembly was checked for leaks. No leak was observed during the temporary service check. However, the adapter remains damaged and should be replaced. This appears to be a manufacturing, assembly, or original filter installation issue, because the vehicle had only approximately 2,900 miles and the factory-installed oil filter was seized to the oil filter threaded union. The filter should not be seized to the adapter at this mileage, and the threaded adapter should not be pulled out of the engine-side housing during normal oil filter removal. The concern is that a damaged or improperly threaded oil filter adapter could cause oil filter sealing failure, oil leakage, loss of engine oil pressure, engine damage, or an oil leak onto the roadway. The damaged threaded oil filter adapter/union should be documented as a factory/dealer assembly defect.
Vehicle was dormant overnight and caught fire. Battery disintegrated and fire tore across the entire engine compartment and front end. Fire department conducted investigation and determined mechanical failure. Showed no signs of issue before hand was driven shortly the night before to move parking spots.
On 1/14/2026, I was pulling into a parking space in a parking garage when the vehicle abruptly accelerated causing the vehicle to hit the concrete wall in front of me. No braking assist or front collision warning issued. Airbags deployed. The car is currently at Joe Myers Collision Center in Houston, Texas to obtain an estimate for repair. The police did not respond to reported incident. Incident was reported to my insurance company immediately.
Cylinder 3, loss of engine power . Safety feature on and off. Life threatening .in the Middle line, suddenly English loss the power almost car behind me crash on us at the time my wife with me in the car . Yes dealer said fuel injector problem , I believe this is more then that . Yes vehicle inspected by dealer under warranty I saw engine logo and something malfunction, but at the I was hurry to drive car on the safe side after that I turn off engine.
The vehicle jerks while slowing down/low speed.
First issue: Rough idle at start. The interior cabin vibrates enough to question the vehicle quality. The rough idle lasts about 40 seconds then engine switches to smooth vibration. It's actually unnerving. Second issue: it's well known in 2025 Mazda installed the Toyota RAV4 hybrid engine and transmission into the CX-50. The current ICE engine model had to be modified. As a result there are some structural issues that may become problematic. The front passenger door scrapes against the interior fender. During...
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manufacturing to cover up the defect Mazda purposely offset the passenger side fender mask the defect. This should seriously can into question the structural integrity of the vehicle. The primary concern is by offsetting the fender have the impacted the ability of the crumble zones in this area? Additionally, the front passenger door may become stuck since there is no uniformity in the panel alignment. This should raise caution since the modifications necessary to accommodate the hybrid system my have impacted overall vehicle integrity.
Check engine light came on at 600 miles. Took it to the dealer and the code was a p3400 code, cylinder deactivation fault. The dealership replaced both solenoids, part #PYFA-12-360A, found metal in OCV valves. When we got the car back I changed the oil, cut the oil filter open and found large metal shavings. At about 1300 miles the same check engine light came on. Back to the dealership with the same code. Now Mazda says to replace the head.
Automatic transmission failure, engine malfunction, safety driver function. My car will not accelerate, or move out of 1,2,3 gear.
I purchased this brand new 2023 Mazda CX-50 at the end of this July, and it has no incidents, no hits, no scratches at all. Last Sunday while driving it, out of no where, the 'Vehicle System Malfunction' message showed up and I dropped my car at the dealership right away. There was the weird sound from the front of the vehicle every time I braked to 10 mph, and I don't want to take risk of my own to drive it anymore. The front right-side lower active grille shutter was broke, and three lit damages were spotted on...
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the condenser behind it. Luckily no leakage happened at that time. The dealership gave it a rounded inspection and told me 'it might be hit by a little rock'. Yeah, a little rock broke the entire grille shutter. I realize that there is no protection of any sort in front of the shutters, and it is very easy for any little object to break the shutters and the condensers as well. You can see easily from any picture of a CX50, there are two open big holes at the lower front, and the shutters are inside. This makes the shutter entirely expose. It's only two months since I bought this car, I believe I will not be the first CX50 owner that has this problem. It is highly possible that this is a design flaw, there should be some protective manners in front of the shutters to reduce the possibilities of something hitting it. Mazda's warranty is not covering this since they told me 'it was damaged by hitting a little rock', but this damage was because there is no protection to the shutter at all.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) complaints and recalls, checked daily. Complaints are owners' own reports and are not verified. How we use the data