On January 25, a 2024 Chevrolet Trax threw a reduced-engine-power warning and stalled with a loud knock from under the hood. Its odometer read 11,581 miles. A dealership diagnosed a broken connecting rod and told the owners the engine would have to be replaced. That replacement was on backorder, and the car stayed where it was.
That vehicle belongs to Samantha and Donna Cook of California, and their experience became the basis of a class action filed against General Motors on March 7, 2026. The suit covers GM’s 1.2-liter turbocharged three-cylinder, an engine that appears in the Chevrolet Trax and Trailblazer and the Buick Envista and Encore GX.
GM has not been found liable for anything. Those allegations are unproven, and discovery has not resolved them.
What can be examined now is the public complaint record. Owners of 2024, 2025 and 2026 Trax models have filed 210 complaints with the National Highway Traffic Safety Administration. A subset of those describe the same sequence the Cooks describe: a bang or a knock, a sudden loss of power, and an engine that will not be repaired but replaced.
Key Takeaways
- A class action filed March 7, 2026 alleges the 1.2L turbo three-cylinder is defective. The named plaintiffs’ 2024 Trax failed at 11,581 miles with a broken connecting rod. The claims are unproven.
- NHTSA complaints describe engine failures as early as 9,500 miles. Verified odometer readings at failure include roughly 9,500, under 14,000, 17,000, 28,000, 28,882, 44,000, 51,000 and 54,546 miles.
- The engine uses a Continental timing belt that runs in engine oil. Belt material can shed into the oil supply as it ages, which is a documented risk of wet-belt designs across the industry.
- Replacement engines are the longer problem. Owners report waits measured in months. One filing records more than 60 days at the dealership; another owner was told there was no arrival estimate after a month.
- Nine fire reports appear in the complaint record for 2024 and 2025 models. At least three started in vehicles that were parked and switched off.
- Electrical complaints outnumber engine complaints, 76 to 53. The engine cases are fewer and more severe.
- GM has issued one recall for these vehicles, and it does not concern the engine. Campaign 23V744000 covers instrument-panel software.
- Complaint totals track sales volume. Chevrolet sold 200,688 Trax in 2024 alone, making it the best-selling vehicle in its segment. Raw counts cannot rank one model against another.
What the Lawsuit Alleges
The Cooks bought their Trax new. According to the filing, the car gave no meaningful warning before the January failure. A message appeared, the engine stalled, and the knocking was loud enough to be unmistakable. They coasted off the road.
A connecting rod ties a piston to the crankshaft. When one lets go at speed, it can punch through the block. The suit alleges GM knew about a defect in these engines and did not disclose it to buyers.
The complaint covers four vehicles that share the powertrain: the Trax and Trailblazer from Chevrolet, the Envista and Encore GX from Buick. Symptoms named in the filing include knocking, mechanical banging, and loss of motive power.
This is the second engine-related class action GM has faced in recent years, following litigation over its V8 engines. Whether the 1.2-liter suit reaches the same posture depends on discovery, and nothing in the filing has been tested in court.
The Failures Owners Describe
NHTSA publishes owner complaints as submitted, without verification. They are self-reported and unaudited. They also carry detail no aggregate figure does, including what the dealership said and what the repair cost.
Engine failures in the 2024 and 2025 record cluster near the start of the ownership window, not at the end of a service life.
| Odometer at failure | What the owner reported | NHTSA ID |
|---|---|---|
| ~9,500 miles | Loud pop while accelerating on the freeway, smoke from the engine bay and tailpipe | 11680331 |
| 11,581 miles | Broken connecting rod (the class action’s named plaintiffs) | Court filing |
| Under 14,000 miles | Sound described as an explosion at highway speed, total power loss, crossed two lanes to the shoulder | 11662100 |
| 17,000 miles | Connecting rod failure, oil and coolant on the ground, engine smoking | 11728313 |
| 28,000 miles | Check-engine light while idling, plus a drop in fuel economy | 11662662 |
| 28,882 miles | Reduced engine power at 70 mph, could not exceed 55 mph afterward | 11669180 |
| ~44,000 miles | Engine stopped, full replacement required | 11706344 |
| 51,000 miles | Low-end knock with vibration | 11717278 |
| 54,546 miles | Failure after documented 5,000 to 7,500-mile oil changes on Mobil 1 and ACDelco | 11680315 |
The complaint at 11662100 is worth quoting because of how little warning it records:
“I heard what sounded like an explosion, lost all power, and had to steer across two lanes where I just made it onto the shoulder of the highway. There was absolutely no warning, no warning lights, no messages at all.” That 54,546-mile case matters for a different reason. That owner drives for Amazon Flex, logged the mileage quickly, and listed the maintenance history in the filing: oil every 5,000 to 7,500 miles, air filters replaced on schedule, spark plugs at 50,000. Neglect is the usual explanation offered when a modern engine fails early. It does not fit that filing.
The Timing Belt Runs in Oil
One owner attributed the failure to a design characteristic rather than to a part, noting that the engine “uses a wet timing belt engine design, where the timing belt runs inside the engine oil.”
That description is accurate. GM’s 1.2-liter three-cylinder uses a Continental rubber timing belt submerged in the oil supply, a layout the company adopted to cut friction and quiet the valvetrain. Ford took the same approach with its 1.0-liter EcoBoost, and the industry has accumulated a decade of field experience with it.
Degradation is the known risk. As a wet belt ages, material can shed into the oil, and that debris can restrict the passages that feed the bearings. Bearings starved of oil fail. A failed rod bearing is one of the ways a connecting rod breaks.
Nothing in the public record establishes that this is what happened to any specific Trax. GM has not attributed these failures to the belt, and the class action’s theory has not been tested. This design does, though, offer a mechanism that connects two otherwise separate groups of complaints: owners reporting oil disappearing between changes, and owners reporting rods letting go.
One filing captures both at once. That owner reported the oil low or absent at successive service visits, changed it every 4,000 miles regardless, and eventually ran the engine dry. A replacement was quoted at $6,700.
Replacement Engines Are the Longer Problem
A destroyed engine in a car under warranty is a repair. A destroyed engine in a car whose replacement powerplant is built in South Korea and backordered indefinitely is something closer to a total loss of use.
Owner 11728313, whose rod failed at 17,000 miles, wrote that there was no estimated arrival date for a replacement and that the car had already sat for a month. Owner 11691756 documented more than 60 days at the shop, then a second failure shortly after the new engine went in: a check-engine light, ticking at 45 mph, and another reduced-power message. Owner 11643559, whose 2025 Trax needed a fuel rail at 156 miles, was told the part had no projected delivery date.
The Cooks’ filing makes the same allegation about backordered engines. For a household running one car, the difference between a two-week repair and a four-month wait is the difference between an inconvenience and a second car payment.
Nine Fires, Three of Them in Parked Cars
Nine complaints against 2024 and 2025 Trax models are flagged as involving fire. Seven name the engine compartment as the origin.
Three began with the vehicle parked and switched off.
One owner was woken at 4:30 a.m. by neighbors after a boom, and found the front of the car engulfed; investigators traced the origin to the engine bay. Another returned to a car that had been parked for two minutes and watched smoke turn into a fire that consumed the front end within ten minutes. A third was alerted by the car’s own alarm at 1:10 a.m. and called the Boston fire department.
Of the moving-vehicle cases, one owner was told by a mechanic that a turbo oil line had combusted and holed the engine. Another saw smoke at 45 mph and the car caught while being steered off the highway.
Nine reports across two model years is not a rate, and it should not be read as one. Fire counts scale with fleet size the same way complaint counts do. What the reports establish is that the failures include a thermal mode, and that some of them occur with nobody in the car.
What the Complaint Numbers Do and Don’t Show
It would be convenient to report that the 1.2-liter generates complaints faster than the 1.4-liter four-cylinder it replaced. That arithmetic holds. It does not survive contact with the rest of the segment.
| Compact SUV | NHTSA complaints per production year |
|---|---|
| Ford Escape (2020-2025) | 478.0 |
| Nissan Rogue (2021-2025) | 260.4 |
| Honda CR-V (2023-2025) | 256.0 |
| Toyota RAV4 (2019-2025) | 195.9 |
| Chevrolet Equinox (2018-2025) | 187.6 |
| Chevrolet Trax (2024-2025) | 139.0 |
| Buick Envista (2024-2025) | 44.0 |
Measured that way the Trax sits below the RAV4, the CR-V and Chevrolet’s own Equinox, roughly fourteenth among the 55 compact SUVs in the database. That metric is close to a sales proxy. Chevrolet delivered 200,688 Trax in calendar 2024, which made it the best-selling vehicle in its class. Independent sales trackers disagree on the 2025 total, placing it between roughly 169,000 and 205,000, and either figure leaves the nameplate among the highest-volume entries in the segment.
More cars produce more filings.
Two other honest qualifications belong here.
Electrical complaints outnumber engine complaints in this vehicle, 76 against 53. An article about the engine that omits that is shaping the evidence. The engine cases stand out for severity rather than frequency, and severity is the reason they warrant separate treatment.
Buick’s Envista comparison is also weaker than it looks. It carries the same 1.2-liter engine and a much lower complaint rate, but Buick sells a fraction of the Trax volume, and low sales produce low counts regardless of engineering.
A defensible reading is narrower than any verdict on the engine’s quality. One specific and severe failure mode is being reported, it surfaces early in these vehicles’ lives, and the remedy takes months. Complaint totals are context for that, not proof of it.
GM Has Issued One Recall, and It Is Not About the Engine
NHTSA lists a single recall campaign against the 2024 Trax. Campaign 23V744000, filed June 11, 2023, covers 2024 Buick Encore GX, Buick Envista and Chevrolet Trax vehicles whose Virtual Cockpit Unit software can blank the instrument panel at startup or while driving.
That campaign addresses the electrical category, which is where the complaint volume sits. It has nothing to do with connecting rods, oil supply or the timing belt.
One owner in the record reported the instrument cluster going dark and was refused a diagnosis because the VIN fell outside the recall population. No engine campaign has been issued for any of the four vehicles named in the class action.
Which Vehicles Share the Engine
The 1.2-liter turbo three-cylinder produces 137 hp @ 5,000 rpm and 162 lb-ft @ 2,500 rpm. GM builds it in Mexico and assembles the Trax in Changwon, South Korea.
The class action names the Chevrolet Trax, the Chevrolet Trailblazer, the Buick Envista and the Buick Encore GX. Engine availability varies by model and model year within that group, and the Trailblazer has offered a 1.3-liter three-cylinder alongside the smaller unit. Any owner checking whether this applies to a specific car should confirm the engine code on the build sheet rather than assume it from the badge.
Full complaint and recall breakdowns for these vehicles are in The Weekly Driver’s reliability database entry for the 2024-2025 Trax, with a separate record for the first-generation Trax built from 2015 to 2022, a different vehicle with a different engine.
What to Do If You Own One
Watch the oil level between changes instead of trusting the service interval. Wet-belt engines that consume oil give the clearest early warning on the dipstick, and the low-oil light in several of these filings never illuminated before the failure.
Treat a knock, a tick, or a reduced-power message as a reason to stop rather than to schedule an appointment. Multiple owners in the record kept driving after the first symptom and lost the engine on a highway.
File a complaint with NHTSA if something happens. Campaigns open on the strength of the complaint record, and the engine category here holds 53 filings against an electrical category that already produced a recall at higher volume.
Keep every service receipt. Oil-change documentation is what separated the 54,546-mile filing from a neglect argument, and it is the evidence any warranty claim or class membership will turn on.
Check the VIN against open recalls at NHTSA’s lookup tool before assuming a car is clear. That single campaign covers a defined production range, and at least one owner in the record fell outside it.
Verdict
The 1.2-liter three-cylinder in the Chevrolet Trax has a documented pattern of severe, early engine failures, an unresolved class action alleging the company knew about it, and a replacement supply chain that leaves owners without a car for months. None of that has been proven in court, and the raw complaint totals are lower than several rivals that sell in similar numbers.
For a buyer, the exposure is not the odds of failure. It is what failure costs. A $6,700 engine on a car that stickers at $27,975, with a wait measured in months, is a different kind of risk than a fault that gets fixed in a week.
Anyone shopping a Trax, Trailblazer, Envista or Encore GX should read the case as open rather than settled, keep maintenance records, and price a used example with the engine’s history in mind. Anyone who already owns one should watch the oil and stop driving at the first knock.
Frequently Asked Questions
What are the most common Chevy Trax engine problems?
Owner complaints filed with NHTSA against 2024 and 2025 Chevrolet Trax models describe connecting rod failure, oil consumption between scheduled changes, sudden loss of motive power, knocking or ticking from the engine, and in nine cases fire originating in the engine compartment. Engine-category complaints total 53 against 76 in the electrical category, so engine faults are less frequent than electrical ones but more severe when they occur.
Is there a lawsuit over the Chevy Trax engine?
A class action was filed against General Motors on March 7, 2026 by California plaintiffs Samantha and Donna Cook, whose 2024 Trax suffered a broken connecting rod at 11,581 miles. The suit alleges the 1.2-liter turbocharged three-cylinder is defective and that GM did not disclose the problem. It covers the Chevrolet Trax and Trailblazer and the Buick Envista and Encore GX. Those allegations are unproven, and no ruling has been issued.
At what mileage does the Chevy Trax engine fail?
The NHTSA complaint record shows failures across a wide range with a cluster early in the ownership window. Verified odometer readings at failure include roughly 9,500 miles, 11,581 miles, under 14,000 miles, 17,000 miles, 28,000 miles, 28,882 miles, about 44,000 miles, 51,000 miles and 54,546 miles. Several owners reported no warning lights before the failure.
Does the Chevy Trax have a wet timing belt?
Yes. The 1.2-liter turbocharged three-cylinder uses a Continental rubber timing belt that runs submerged in engine oil, a design GM adopted to reduce friction and noise. As wet belts age, material can shed into the oil and restrict the passages that feed the engine’s bearings. GM has not attributed any Trax engine failure to the belt, and no recall has been issued regarding it.
How much does a Chevy Trax engine replacement cost?
One owner in the NHTSA record was quoted $6,700 for a replacement engine after theirs failed from oil loss. Cars still under GM’s powertrain warranty should be covered, but the practical cost for many owners has been time rather than money. Replacement engines are built in South Korea, and complaints document waits exceeding 60 days, with at least one owner told there was no estimated arrival date after a month.
Has Chevrolet recalled the Trax for engine problems?
No. NHTSA lists one recall campaign against the 2024 Trax, campaign 23V744000, filed June 11, 2023. It covers Virtual Cockpit Unit software that can blank the instrument panel at startup or while driving, and applies to the 2024 Buick Encore GX, Buick Envista and Chevrolet Trax. No recall has been issued for the engine in any of the vehicles named in the class action.
Which vehicles use the GM 1.2L three-cylinder engine?
The 1.2-liter turbocharged three-cylinder appears in the Chevrolet Trax, the Chevrolet Trailblazer, the Buick Envista and the Buick Encore GX, all four of which are named in the class action. Engine availability varies by model and model year, and the Trailblazer has also offered a 1.3-liter three-cylinder. Owners should confirm the engine code on the build sheet instead of assuming it from the model name.
Is the Chevy Trax reliable?
Measured on complaints per production year, the 2024-2025 Trax records 139.0, which places it below the Toyota RAV4 at 195.9, the Honda CR-V at 256.0 and the Chevrolet Equinox at 187.6, and roughly fourteenth among 55 compact SUVs in The Weekly Driver’s database. That metric tracks sales volume closely, and Chevrolet sold 200,688 Trax in 2024 alone. The concern with this vehicle is the severity of the engine failures reported rather than the overall volume of complaints.
Should I buy a used Chevy Trax?
A used 2024 or 2025 Trax carries a specific unresolved risk: an engine failure mode that can occur under 15,000 miles and a replacement supply chain that has left owners waiting months. Buyers should check the VIN against open NHTSA recalls, request complete oil-change documentation, and factor the class action’s unresolved status into the price. A first-generation Trax built from 2015 to 2022 uses a different engine and does not share this issue.
What should I do if my Trax engine starts knocking?
Stop driving and arrange a tow rather than continuing to a dealership. Several NHTSA complaints describe owners who kept driving after an initial knock, tick or reduced-power warning and then lost the engine at highway speed, in some cases having to cross traffic lanes to reach the shoulder. File a complaint with NHTSA afterward, since recall campaigns open on the strength of the complaint record.
Manufacturer Disclosure and Sources
The manufacturer provided The Weekly Driver with a 2026 Chevrolet Trax 1LT, which supplied the photography published here. No driving evaluation informed the analysis, which is based on court filings, the NHTSA complaint and recall databases, and The Weekly Driver’s reliability database. Complaint text is quoted as filed and has not been independently verified. Sales figures are US deliveries for calendar 2024; independent trackers disagree on the 2025 total, which is given as a range.
Michael Kahn
Michael Kahn is the writer, photographer, and publisher behind The Weekly Driver. He cares about how cars drive and what they're like to own. He covers automobile industry news, car shows and events, and new car reviews. The reviews come from behind the wheel: day trips that favor back routes, treating a good meal as half the reason to go. He directs and produces the visual media, matching each car to a setting and mood that fit it. When he's not reviewing new cars, Michael races paddleboards, camels, and ostriches, along with the occasional exotic car on the racetrack, and has driven in every state and country visited.
https://theweeklydriver.com