Complaint volume
290 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
2018 GMC Sierra Complaints
290 consumer-submitted complaints on record for the 2018 GMC Sierra, grouped by component category.
290 Total complaints
10 Crash reports
1 Fire reports
5 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 power train, engine, service brakes. Use those categories as a test-drive checklist instead of judging the vehicle from the total count alone.
Severity flags
Enriched records include 10 crash reports, 1 fire report, 5 injury reports, and 0 fatality reports. These fields come from complaint records and should be read in context.
Mileage clue
Mileage is available on 121 complaints, with an average reported failure mileage of 45,272 miles. Compare that with the mileage on the listing.
Questions to ask the seller
- Have you had any problems related to power train, engine, service brakes?
- 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 2018 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.
2018 GMC Sierra
Build buyer checklist Compare with other years Sends year, make, and model to pre-fill your checklist.
How severe are the 2018 GMC Sierra complaints?
10 Crash
1 Fire
5 Injury
0 Fatality
12 Towed
3 Medical attention
What are the most common 2018 GMC Sierra complaint categories?
POWER TRAIN 85
ENGINE 30
SERVICE BRAKES 15
UNKNOWN OR OTHER 14
ELECTRICAL SYSTEM 11
ELECTRICAL SYSTEM,SERVICE BRAKES 10
POWER TRAIN,ENGINE 10
STEERING 10
AIR BAGS 6
SEAT BELTS 4
290 total complaints on record
Latest complaints
| Date | Component | Summary | Severity | Mileage |
|---|---|---|---|---|
| Oct 2023 | ENGINE | I am told by a GMC dealer that my engine mount is cracked/worn and needs replacing otherwise the engine can fall out. My mechanic tells me this is a common problem with GMC trucks; specifically the driver’s side engine mount. Perhaps a recall is necessary if this is a common issue. My vehicle is a 2018, so only 5 years old. | Crash: No Fire: No | Unknown |
| Sep 2023 | TIRES | In May 2022, I purchased four Cooper Discoverer A/T All-Season 117T 275/55/R20 tires from Walmart.com for my 2018 GMC Sierra 1500 SLT. In May 2023 my vehicle developed a vibration when driving at certain speeds, so I took it to a GMC dealer for a tire rotation and balance. The mechanic discovered that one of the tires had a large bubble on the inner sidewall. He considered it such a safety risk that he insisted on removing the tire and replacing it with the spare before he would let me drive home. The tire was replaced with another of the same kind and tread depth. Yesterday (September 28 2023) I felt that my truck was wandering and swaying. I made an appointment for it to be inspected on Monday, and planned not to drive it until then. Today I observed that the rear passenger tire appeared low. I was shocked to find a split in the inner sidewall approximately one third of the circumference of the tire. I also found a large bubble on the inner sidewall of the driver's side front tire. I am shaken that I could have had three different tires blow out potentially killing myself and other motorists. I will be retaining the tires for inspection, and photographs have been taken. The manufacturer has been contacted. It seems that other model tires have been recalled by Cooper for the same issue, but I have not found a recall for this specific tire. | Crash: No Fire: No | Unknown |
| Sep 2023 | POWER TRAIN | Transmission shudder at different speeds while driving. | Crash: No Fire: No | Unknown |
| Sep 2023 | POWER TRAIN | On approximately July 23, 2023, I noticed the vehicle transmission shifting hard from 1st to 2nd gear and then during the following week, this began to occur every time I drove the vehicle. There were no warning indicators appearing on the vehicle for this problem during vehicle operation. Then at higher steady speeds, the engine RPMs began to suddenly and intermittently surge slightly higher, and the steering wheel would shudder for a few moments. This began to occur more frequently and I became concerned that the transmission would catastrophically fail, causing a crash and/or personal injury. At that point I called a local dealer to make an appointment for a transmission oil change and inspection. The vehicle was taken to a local dealer on August 21, 2023 and they confirmed that there was a problem with the transmission, though at this time final diagnosis is pending. To my knowledge, the vehicle or component has not been inspected by the manufacturer, police, insurance representatives or others since I took it to the dealership on August 21, 2023. | Crash: No Fire: No | Unknown |
| Aug 2023 | ENGINE | The contact owns a 2018 GMC Sierra 1500. The contact stated that while turning left at an undisclosed speed, the vehicle lost motive power. No warning light was illuminated. The contact was able to restart the vehicle; however, the failure recurred. The vehicle was taken to the dealer; however, the dealer was unable to duplicate the failure. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 72,000. | Crash: No Fire: No | 72,000 |
| Jun 2023 | POWER TRAIN,ENGINE | The contact owns a 2018 GMC Sierra 1500. The contact stated while driving from a complete stop and depressing the accelerator pedal, the engine revved but the vehicle hesitated to respond. There was no warning light illuminated. The contact stated that the failure reoccurred several times. The vehicle was taken to the local dealer, where it was diagnosed that the transmission was slipping and needed to be replaced. The vehicle was repaired. Additionally, the contact stated while driving 60-65 MPH, the vehicle started vibrating and shuddering. The check engine warning light was illuminated. The contact was able to drive to her nearby destination. The vehicle was towed to a second dealer Liberty Chevrolet (105 Cooley Way, Villa Rica, GA 30180) where it was diagnosed that the driver's side lifters had failed and needed to be replaced. The vehicle was repaired; however, the failure reoccurred. The vehicle was towed to a third dealer, Prince Chevrolet Buick GMC of Albany (2701 Ledo Rd, Albany, GA 31707) where it was diagnosed that passenger's side lifters needed to be replaced. Additionally, the dealer diagnosed that the camshaft needed to be replaced. The contact was advised that the warranty would cover a portion of the cost of the repair and she was responsible for the balance. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 84,267. | Crash: No Fire: No Towed | 84,267 |
| Jun 2023 | ENGINE | When I’m towing my small boat, my temperature gauge starts to rise on my engine and there are no warning lights and it has caused me to have to pull over. I have told the dealership about this. Everyone seem to act like it’s no big deal but when I’m having to pull over, because I’m afraid my motors getting too hot, it’s a problem. And not only that even when I’m not towing anything my temperature gauge keeps going up then back down up and then back down never in my life have I experienced a vehicle doing this | Crash: No Fire: No | Unknown |
| Jun 2023 | POWER TRAIN | The contact owns a 2018 GMC Sierra 1500. The contact stated that while depressing the accelerator pedal, the vehicle failed to properly accelerate. The vehicle was towed to the local dealer who diagnosed the vehicle and determined that the transmission was faulty; however, the part needed to fix the vehicle was not available. The vehicle was not repaired. The manufacturer was not yet notified of the failure. The failure mileage was 27,477. | Crash: No Fire: No Towed | 27,477 |
| Apr 2023 | ELECTRICAL SYSTEM | Loss of dash electrical system and service stabillitrac warning came on when power was restored along with service suspension warning light. Headlights flicker and engine starts powering down before power comes back on by itself. If fuse to suspension is pulled or negative is removed and replaced, all warning lights go away. | Crash: No Fire: No | Unknown |
| Apr 2023 | ELECTRICAL SYSTEM,SERVICE BRAKES | Break system is making scratching noises as if it is a caliber breaking problem or a caliber piston problem, it is also setting off the trailer breaking system light on the dash as well as the trail traction control light. | Crash: No Fire: No | Unknown |
| Apr 2023 | STEERING,SUSPENSION,WHEELS | Noticed a scraping noise after new, recommended tires installed on my stock truck. Checked the door label to ensure correct tires installed, they were, returned to the tire facility and they recommended I ask a repair facility to investigate. Found that the tires are rubbing the upper control arm when fully turned left or right (both sides affected). Went online to discover that this is a common issue with the 2018 and similar GMC Sierra and Chevy Silverado trucks. This is a safety issue caused by a design deficiency. Two things can happen. One, the tire can fail. Two, the upper control arm could fail, causing the vehicle to be uncontrollable. This could be fixed by restricting the extreme left and right travel in the steering system or redesigning and replacing the upper control arm so it doesn’t interfere with the tire. This is an unacceptable safety issue caused by a design deficiency and needs to be addressed by NTSB now. | Crash: No Fire: No | Unknown |
| Apr 2023 | ENGINE | Radiator failed. Mileage is under 60k. It is currently being replaced by dealership. Dealer Representative noted that it is a fairly regular occurrence for these models. So much so that the dealership stocks this replacement radiator(hard for me to understand). There was no indicator lights to alert to this malfunction, it was noticed after work one afternoon when coolant was dripping out of the front of the vehicle. | Crash: No Fire: No | Unknown |
| Apr 2023 | POWER TRAIN | When the transmission is making changes, there is a shaking noise. | Crash: No Fire: No | Unknown |
| Apr 2023 | POWER TRAIN | The contact owns a 2018 GMC Sierra 1500. The contact stated while accelerating from a traffic light, the vehicle started hesitating. The contact stated no warning light was illuminated. The vehicle was not diagnosed or repaired. A dealer was not contacted. The manufacturer had not been informed of the failure. The failure mileage was approximately 99,000. | Crash: No Fire: No | 99,000 |
| Mar 2023 | POWER TRAIN | Transmission failure - the GM manufactured Torque converter on my truck failed to cause the transmission to fail. The internet is rife with stories of the failure of these transmissions on 2018 and 2019 GMC and Chevy Trucks. | Crash: No Fire: No | Unknown |
| Mar 2023 | SEAT BELTS | THE MIDDLE REAR SEATBELT FAILS TO LOCK WHEN RETRACTED, THEREFORE I CANNOT USE MY GRANDCHILD'S BOOSTER SEAT. THE DEALERSHIP HAS ORDERED A REPLACEMENT, BUT COST NEARLY $300. I BOUGHT THE VEHICLE NEW IN DECEMBER 2018, BUT HAVE NEVER HAD TO USE THE REAL SEATBELT UNTIL NOW. THEREFORE I DID NOT KNOW IT DID NOT WORK PROPERLY UNTIL NOW. | Crash: No Fire: No | Unknown |
| Mar 2023 | POWER TRAIN | 8 speed transmission jerking, the torque convertor has been replaced 1 time already and having same issues as before. This time while in parking lot at store, was pulling into parking space, truck lundge forward during hard downshift hitting cart of person walking in front of truck. No damage and luckly barely hit the cart and not the person. I have also had the truck lunge forward when parking in my garage and hitting the garage wall in front. My truck is back at dealer again after hitting the cart in the parking lot. The 8 speed transmission issue from GM is a safety issue. My truck has already had first torque converter replaced and now having same issue with the new torque convertor | Crash: Yes Fire: No | Unknown |
| Jan 2023 | POWER TRAIN | noticed ongoing vibration sounds like you are running over rumble lines on road. | Crash: No Fire: No | Unknown |
| Jan 2023 | SERVICE BRAKES,FORWARD COLLISION AVOIDANCE | Braking vehicle will cause brake pedal to vibrate and become soft while pressing it and requires more effort to stop vehicle. Service brake assist light laminates on info system. I know there is a recall for this currently but my vehicle is not listed for this all though i have the same issues. Recall is N202300860. | Crash: No Fire: No | Unknown |
| Jan 2023 | ELECTRICAL SYSTEM | The main harness under the truck , front to back . There was a separation from the conduit, wires exposed and were arcing. Truck would not start . I have since had it fixed . I just feel truck is not that old , to soon for a problem like this . And it cost a lot of money. | Crash: No Fire: No | Unknown |
| Jan 2023 | STEERING | Hit a small bump driving 55mph on highway and had sudden complete power steering loss and extremely hard to turn. Drove to a safe location and shut down truck for 1 hour. Upon restart power steering was operating normal. Proceeded back on the freeway and as soon as I hit a small bump with driver's side front tire the same thing happened again complete power steering loss. Drove to dealership and waiting for explanation. The truck is not safe due to inability to turn the wheel without power steering. For someone with less strength, this could be deadly on anything besides a straight road, needing to turn a corner, or to avoid a collision. | Crash: No Fire: No | Unknown |
| Dec 2022 | ELECTRICAL SYSTEM,SERVICE BRAKES | I purchased my 2018 GMC Sierra 1500 pickup truck new in 2018. To date it only has 28K miles on it. I have never used the trailer breaking system that it came equipped with. On 12/24/22 we were traveling to a family function for Christmas. The "service trailer break system" warning message came on and the chime chimed continuously until I got to my destination, about an hour away. This chime was very distracting and there was no way to turn it off. After arriving at my destination I turned the truck off hoping it was just a fluke. When I started the truck back up the "service trailer break system" warning light and chime continued. It continued for an hour on my way home. Again, this was very distracting and I was unable to focus 100% of my attention on the road and my driving. Thank fully I made it home okay. On 12/27/22 I took the truck to my mechanic to have him take a look. He said he has heard of this issue with these pickups. His diagnostic confirmed that the trailer breaking switch (on the dash) was functioning properly but said that the chassis control module was likely the culprit. He replaced the control module and it had to be programed by a factory technician. After this part was replaced the warning light or chime does not come on anymore. I have the defective part for inspection and the bill totaling $1191.86 for the repair upon request. | Crash: No Fire: No | Unknown |
| Dec 2022 | SERVICE BRAKES | I purchased this 2018 GMC pickup in May 2021. Starting in Nov 2022 I started getting a sporadic SERVICE TRAILER BRAKE SYSTEM warning light and chime. I have never towed a trailer using this trailer brake system on the vehicle, but the warnings come on sporadically. I have done some research and found this is not an isolated case as others have reported the same problem. Some owners have replaced the dashboard controller at their own expense, however this is now a well documented problem that goes beyond an isolated case. This is a defect of the trailer brake controller and should be recalled by GM at GM expense. It is a hazard to driving when the visual and audible chime come on sporadically. It's a distraction to safe driving and requires immediate intervention. I did advise my local dealer of the problem when the vehicle was serviced Dec 2022, however they did not have a technician available to work the problem. So I continue receiving the visual and audible warning every time I drive the vehicle. Please highlight this problem within your organization for a possible safety recall. | Crash: No Fire: No | Unknown |
| Dec 2022 | POWER TRAIN | The contact owns a 2018 GMC Sierra 1500. The contact stated while driving 50 MPH, the vehicle started shaking and vibrating abnormally. There was no warning light illuminated. The vehicle was taken to the dealer to be diagnosed. The contact was informed that the transmission oil needed to be flushed. The vehicle was not repaired. The manufacturer was not contacted. The failure mileage was 71,000. | Crash: No Fire: No | 71,000 |
| Dec 2022 | UNKNOWN OR OTHER | Sunroof shattered while driving on the interstate | Crash: No Fire: No | Unknown |