Complaint volume
60 consumer-submitted complaints are matched to this model year. Treat the count as a research signal, then read the actual summaries for repeated symptoms.
Complaint records
2026 GMC Sierra Complaints
60 consumer-submitted complaints on record for the 2026 GMC Sierra, grouped by component category.
60 Total complaints
0 Crash reports
0 Fire reports
0 Injury reports
Complaint data reflects consumer-submitted reports. A complaint is not proof
of a defect, recall, or manufacturer fault. Enriched severity fields come
from official bulk records when the complaint can be matched by ODI number.
Buyer interpretation
How to use these complaints before buying
Complaint records are most useful when they turn into inspection points, seller questions, and comparison checks against nearby model years.
Pattern to inspect
The most common categories are engine, power train, forward collision avoidance: warnings. Use those categories as a test-drive checklist instead of judging the vehicle from the total count alone.
Severity context
The enriched records we matched do not show crash, fire, injury, or fatality flags. Still check complaint summaries for repeated drivability, braking, electrical, or visibility symptoms.
Mileage clue
Mileage is available on 4 complaints, with an average reported failure mileage of 5,330 miles. Compare that with the mileage on the listing.
Questions to ask the seller
- Have you had any problems related to engine, power train, forward collision avoidance: warnings?
- Can I see recent maintenance and repair records?
- Has the vehicle ever been towed, involved in a crash, or repaired for the same issue twice?
- Can we also check the recall record for this 2026 GMC Sierra?
Used-car checklist
Use these complaints before the test drive.
Build a buyer checklist to turn these issues into questions and inspection points.
2026 GMC Sierra
Build buyer checklist Compare with other years Sends year, make, and model to pre-fill your checklist.
How severe are the 2026 GMC Sierra complaints?
0 Crash
0 Fire
0 Injury
0 Fatality
2 Towed
0 Medical attention
What are the most common 2026 GMC Sierra complaint categories?
ENGINE 30
POWER TRAIN 8
FORWARD COLLISION AVOIDANCE: WARNINGS 2
SERVICE BRAKES 2
UNKNOWN OR OTHER 2
BACK OVER PREVENTION 1
ELECTRICAL SYSTEM,BACK OVER PREVENTION 1
ENGINE,FUEL/PROPULSION SYSTEM 1
EQUIPMENT 1
FORWARD COLLISION AVOIDANCE 1
60 total complaints on record
Latest complaints
| Date | Component | Summary | Severity | Mileage |
|---|---|---|---|---|
| Jan 2026 | ENGINE | I heard a loud metallic knock that was not consistent with normal engine noise. I noticed the oil pressure was on the lower end of the scale but not abnormal based on how it is displayed. I decided to take the vehicle to the dealer ASAP for an oil change (that was coming due) and discuss with them. I drove roughly 20 miles from start of noise until delivery at the dealer. The truck gave me a "Reduced Acceleration, drive with caution" message 10 miles prior to the dealership but no associated lights, engine codes, check engine light or associated alerts on the myGMC app. Dealership found oil pressure ranging between 4-8 psi, and a failed oil pressure control solenoid, heavy metal debris in the oil pan including parts of the thrust bearing and oil squirter. Entire engine and turbo replacement was required. Truck had 143 hours on the engine and 6,300 miles. It was produced in August of 2025 with a purchase date of 17 October 2025. Produced: 8/25 Purchased: 10/17/25 Failed: 12/30/2025 Returned with new Engine: 1/23/26 | Crash: No Fire: No | Unknown |
| Jan 2026 | FUEL/PROPULSION SYSTEM | 2026 GMC Sierra Elevation X31 with 3.0 Duramax Diesel engine, 132-miles, thrust bearing 1.53-mm out of tolerance requiring engine and turbo replacement. Engine build date 25219 (07 AUG 2025), vehicle assembly date August 2025, purchased 10 OCT 2025, entered service for engine and turbo failure on 11 NOV 2025, returned 10 JAN 2026. | Crash: No Fire: No | Unknown |
| Jan 2026 | POWER TRAIN | 26’ GMC Sierra 1500 AT4 3.0l Duramax experiencing Harsh shifting occurring sporadically while accelerating and deceleration. More frequent and severe during quick deceleration. Severe clunking/rear wheel lock up while reversing. Very repeatable. Truck was a dealer demo and had 2400 miles on it when I bought it last week. Took it in to the dealer today and they said I need a complete new transmission. | Crash: No Fire: No | Unknown |
| Jan 2026 | ENGINE | 2026 Sierra 1500 AT4 with 3.0L Duramax Diesel. Three major issues. 1. 2960 miles, thrust bearing failure caused low oil pressure and internal damage. Vehicle needs complete engine replacement. The truck is still at the dealer with no ETA on engine arrival and replacement. 2. Vehicle has severe electrical issues. battery replaced on second day of ownership due to over charge and smoking. The truck would randomly lose the ability to produce sound through infotainment system on start. This includes warning sounds and audible turn signal sound. Dealer said it’s caused by faulty Amp which was replaced. 3. The truck shut off (full system shutdown) and the transmission failed over to neutral while driving on the highway and failed to restart. Barely restarted on second attempt. Dealer has no idea why it is doing it. However the vehicle was throwing multiple code related to transmission module failure, brake module failure, transmission module failure, etc. | Crash: No Fire: No | Unknown |
| Jan 2026 | ENGINE | 3.0 Duramax Engine Failure - 2026 GMC Sierra 1500 Denali Ultimate at just 6,755 miles and only 77 days of ownership. Within the first few thousand miles, the truck intermittently had warnings appear of “reduced acceleration, drive with care”. The truck would limit its ability to maintain speed. When it occurred during highway driving, it was particularly dangerous. The check engine light would also come on. After parking the vehicle for a bit and restarting it, things returned to normal. At the dealership, we reported the issue and leaned the computer reveled a P06DD code which required them to check the crankshaft for excessive play. Our truck was out of specification requiring complete engine replacement at just 6,755 miles. “Service Bulletin 25-NA-307 which states this code may set due to thrust bearing failure. following 25-NA-307 checked crankshaft end play and got a reading of 0.3400 in. the maximum spec is 0.0124 in.“ GM and Laura Buick GMC should not have sold this truck to us without inspecting it for this known issue. This extensive repair required complete removal of the cab from the chassis. | Crash: No Fire: No | Unknown |
| Dec 2025 | POWER TRAIN | My 2026 GMC 1500 is equipped with the 2.7L L3B & 8L90 Transmission. At approximately 1000 miles, I noticed that in 2nd between 2700-3200 RPM, a vibration could be felt throughout the cabin and would occur whether with or without throttle application. I am able to recreate the issue during hard acceleration or placing in manual mode. No matter the Vehicle mode selection (sport, normal, snow, tow/haul, etc.), the issue still persists. I took the vehicle to a local GMC dealer at approximately 6K miles to diagnose. I requested that we test drive another 1500 with the same 2.7L and Transmission. They brought out a 2026 Elevation Quad Cab with the 2.7L; less than 20 miles on the odometer.The same vibration was present in 2nd gear at same RPM band. I requested that the issue be escalated to a local GM rep. for further investigation. However the response from the dealer was inadequate and basically stated that no warranty work would be considered because it seems to be “normal operation”. | Crash: No Fire: No | Unknown |
| Dec 2025 | UNKNOWN OR OTHER | I saw the report regarding models of Chevrolet trucks not receiving owners manuals from factory. I purchased a 2026 GMC AT4 in early October 2025. It didn't come with a manual either. I emailed my sales person at Ewing GMC in Plano, Texas informing him that it was missing the manual and I was told that GM had decided to only include physical manuals with Denali grade trucks. This didn't make any sense whatsoever. I would prefer to have a physical manual available to reference in the event of vehicle issues. | Crash: No Fire: No | Unknown |
| Dec 2025 | SERVICE BRAKES, HYDRAULIC | The contact owns a 2026 GMC Sierra 1500. The contact stated that upon starting the vehicle and shifting into reverse(R), the vehicle failed to move while depressing the accelerator pedal. The contact felt a hesitation while depressing the brake and accelerator pedals, and the contact then attempted to restart the vehicle. The contact restarted the vehicl;e however, while attempting to accelerate, the brakes independently activated. Despite the repeated failure, the contact was able to pull into a gas station to restart the vehicle. The contact stated that after several attempts, the vehicle finally resumed normal operation, and the contact drove the vehicle to the residence. The next day, the contact test drove the vehicle, and the failure reoccurred while the contact was attempting to park the vehicle in a parking spot. The vehicle was taken to a dealer, where a diagnostic test produced 7 fault codes; however, the mechanic was unable to repair the vehicle. The manufacturer was notified of the failure, and the manufacturer stated that there was a communication disconnect between the contact and the dealer. A case was filed with the manufacturer. The vehicle was not repaired. The failure mileage was approximately 300. | Crash: No Fire: No | 300 |
| Oct 2025 | ENGINE | I do not have an official communication from the dealer who is servicing my vehicle. However, they have had my vehicle for almost 3 weeks and they tell me that the engine has failed and needs complete replacement. They said the engine lost compression and quit running, it now cranks and does not start. Although the engine has not been disassembled we believe the point fo failure to be in the rotating assembly of the bottom end of the engine. | Crash: No Fire: No | Unknown |
| Sep 2025 | UNKNOWN OR OTHER | Ac not working properly. Ac blows air to defrost vents foging front windshield and side windows causing bad visibility | Crash: No Fire: No | Unknown |