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 |
|---|---|---|---|---|
| Jun 2024 | POWER TRAIN | We purchased our 2018 GMC Sierra 1500 z71 brand new at Fairway Buick GMC in Las Vegas, NV. Pretty much off the lot we noticed some hard shifting, but over the last year/around 60,000 miles it has become progressively worse. Come to find out GM is aware of a known defect in the transmission used in this make/model and several others by GM which causes hard shifting and jerking while upshifting and down shifting primarily between 1st and 2nd gear. This malfunction has caused the vehicle to activate "limp mode" which doesn't allow the vehicle to move out of 1st gear, while driving on the road, putting the safety of the occupants and others on the road at risk. This first happened in January 2024 while we were moving and towing a 6' U-Haul trailer. Luckily we were within a few miles of our destination and made it there safely. Upon taking it to Autonation Buick GMC, we were told they had seen this issue before and the only solution would be to replace the transmission and would cost roughly $6,000-$8,000, and that's with the generous 20% discount they were willing to offer. We opted to have the transmission flushed instead and it seemed to fix the problem temporarily. Then on [XXX] while decelerating and coming to a stop light it hard shifted from 2nd to 1st then the check engine light came on and limp mode was activated. It was 110 degrees on this day in Las Vegas when my husband was driving home from work, and again by the grace of God, he was only 5 minutes from home and made it there safely. However, what if this had occurred with our two young children in the vehicle and we were no where near home? We would have been stranded in dangerous conditions potentially putting our safety as risk. This KNOWN defect in GM transmissions is 100% a safety risk and this needs to be investigated and recalled immediately. There is an ongoing class action lawsuit against GM regarding this issue and I will be looking to get involved as well. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6) | Crash: No Fire: No | Unknown |
| Jun 2024 | STEERING,SUSPENSION | I have a 2018 GMC Sierra 1500 that I bought new in Oct of 2018 and it now has 15,756 miles on it and was still like new at the time of failure. On May 23rd I was driving the truck when the driver suspension suddenly had an structural failure (mostly the ball joint coming out of the control arm) causing the front right side of the suspension to collapse while driving. This caused the truck to go left of center into on coming traffic resulting in a traffic accident. | Crash: Yes Fire: No Towed | Unknown |
| May 2024 | ELECTRICAL SYSTEM,UNKNOWN OR OTHER,SERVICE BRAKES | I purchased my Sierra in 2021 and 2 weeks after purchase I got a warning for service stabilitrk and another for trailer brake system. This is very very annoying and also has my abs light on. My next issue is a code u510 for active grille shutter assembly. Please fix these issues as they are very common and unsafe. Not to mention as much ad I paid for this truck. | Crash: No Fire: No | Unknown |
| May 2024 | UNKNOWN OR OTHER | Vehicle is shaking at highway speeds | Crash: No Fire: No | Unknown |
| May 2024 | POWER TRAIN,VEHICLE SPEED CONTROL,ENGINE | 2018 gmc Seirra 1500 8 speed transmission. Making unsafe conditions while driving transmission tends to make hard shifts, jerks, hesitation when moved into gear, gets worse when stopping momentarily at stop lights and then trying to accelerate vehicle will not move. Makes hard shift and jerks then will accelerate in an unsafe manner. | Crash: No Fire: No | Unknown |
| Apr 2024 | SUSPENSION | The contact owns a 2018 GMC Sierra 1500. The contact stated that while the vehicle was at an independent mechanic for an oil change, the independent mechanic performed a full inspection of the vehicle. The contact was informed that the CV axles were corroded, and the CV axles needed to be replaced. The vehicle was repaired. The contact was advised to report the failure to the dealer. The contact informed the dealer of the failure. The contact stated that the vehicle had been taken back to the dealer several times for repairs, including the transmission replacement, radiator replacement, and a full suspension replacement. The manufacturer was made aware of the failure. The failure mileage was approximately 93,555. | Crash: No Fire: No Towed | 93,555 |
| Apr 2024 | VISIBILITY | See attached document for complaint | Crash: No Fire: No | Unknown |
| Apr 2024 | POWER TRAIN | My 2018 gmc 1500 transmission making noise grinding. It only has 75799 Miles on it. I just was told by Laura gmc that my transmission needs replacing. I think gm should cover that. Dealer charging 7800.00 to replace it. That's not right the truck doesn't have that many miles on it. Please help | Crash: No Fire: No | Unknown |
| Apr 2024 | POWER TRAIN,ELECTRICAL SYSTEM,SERVICE BRAKES | Transmission started to shutter at 24000 miles. Dealer said couldn’t find anything. ABS and Stabilitrack light came on at about 40,000 miles off and on. Both these problems could result in a crash. On freeway or streets. The display information/ radio has a mind of its own. Connects to any phone number or start the on star call and etc. it takes your attention off the road and can result in a crash. | Crash: No Fire: No | Unknown |
| Apr 2024 | UNKNOWN OR OTHER | AC condenser went out on my vehicle with 100,000 miles, lots of reviews online stating this is a known problem but yet there is no recall. Torch Converter going out at 80,000 miles. | Crash: No Fire: No | Unknown |
| Apr 2024 | POWER TRAIN | Hard changes with transmission like a car has hit you from behind. It has had a hit in the transmission changing gears since 15,000 miles but it has progressively gotten worse and at 67k it’s enough to knock you to change steering direction. | Crash: Yes Fire: No Injuries: 1 | Unknown |
| Apr 2024 | POWER TRAIN,ENGINE | The contact owns a 2018 GMC Sierra LD. The contact stated the vehicle experienced jerking and shaking. The contact also stated when the accelerator pedal was applied, the vehicle made a loud noise and lunged. There were no warning lights illuminated. The vehicle was taken to the dealer where a transmission flush and an alignment were performed. However, the contact stated the failure persisted. The manufacturer was notified of the failure and a complaint was filed. The failure mileage was approximately 30,000. | Crash: No Fire: No | 30,000 |
| Apr 2024 | ELECTRICAL SYSTEM,SERVICE BRAKES | I kept getting a constant alert on my vehicle dash board that said "service trailer brake system" the beeping alert was quite literally constant and it covered up the digital speed odometer, every time I tried to acknowledge the alert it would just pop up and start beeping again. I searched online and quickly realized that this problem with the brake system has plagued GM vehicles for several years and I attempted to fix the issue myself by buying factory parts that other GM owners stated was the issue but it did not correct the issue. I ended up needing to take it to a GM service center and my vehicle was there for 2 business days and it ran me several hundred dollars to have GM fix the issue in the electrical brake system. Again according from online research this problem has plagued a large number of GM vehicles and it would be nice to see GM issue a recall and correct the issue so other people don't end up in the situation I was in. | Crash: No Fire: No | Unknown |
| Mar 2024 | SERVICE BRAKES | The truck is throwing a repeat of service trailer break | Crash: No Fire: No | Unknown |
| Mar 2024 | POWER TRAIN | At 66,963 miles my transmission failed while driving. The check engine light came on and the car would not shift out of first gear. The car was towed into Gilchrist GMC in Tacoma WA. and I was informed I needed a transmission replacement, cost of $7552.24. Come to find out there is a class action lawsuit currently filed for GM owners of this transmission, claiming some 800,000 GM products contain a knowingly faulty transmission. A recall should be in place being that nearly a million vehicles are affected by this. | Crash: No Fire: No | Unknown |
| Feb 2024 | SERVICE BRAKES | Getting message on console "Service - Trailer Brake System". This could result in trailer brakes to fail while pulling loads. | Crash: No Fire: No | Unknown |
| Feb 2024 | ELECTRICAL SYSTEM,SERVICE BRAKES | Have experience increased brake pedal effort, hard brake pedal, and/or potentially increased. stopping distance. The condition is more prevalent at low speed when softly applying the brakes. The Driver’s Information Center, (DIC) “Service brake assist” alert will activate. Extreme safety risk to myself and my children. Bulletin N182202780 & NT192268490 needs to be tied to this specific VIN Number as well. | Crash: No Fire: No | Unknown |
| Feb 2024 | UNKNOWN OR OTHER | Like many of the 2014 and 2015 models, my vehicle has experienced the exact same failure in the radiator due to the thermostat over cycling. There is already a TSB for those models, yet GM changed nothing in the subsequent models and the problem persists. | Crash: No Fire: No | Unknown |
| Jan 2024 | POWER TRAIN | I have been experiencing ongoing issues with the transmission of the vehicle I purchased in 2018. Despite it being a brand new vehicle with only 10,000 miles, I have had to bring it back to the dealer multiple times for transmission-related problems. We have tried changing the transmission fluid periodically to address the issues with shifting and shuddering, but the problem has persisted throughout my ownership. | Crash: No Fire: No | Unknown |
| Dec 2023 | UNKNOWN OR OTHER | I have had my truck in the shop several time for the rear springs they finally replaced the springs and I am having trouble again my warranty is out but I took it to see if gm would take care of the problem but they don’t seem to want to do anything and I no my vehicle is not the only one that has had this issue | Crash: No Fire: No | Unknown |
| Nov 2023 | POWER TRAIN | I have a 2018 GMC Sierra 1500, it is over 5 years. So we all know our warranties are either expired and meaning out of pocket expenses will come. I mainly drive back and forth to work so my vehicle only 43,924 miles to be exact. So tell me why GM allows us to purchase a vehicle with defect oil in the transmission knowing the Torque converter will start shuttering causing some of us to purchase a new transmission and if we lucky a transmission flush. So yes I took it to the dealership causing me over $850 to have a diagnosis, computer hook up, and a transmission oil flushed and replaced. I was told this is an 45000 miles issue and it's not considered a safety issue. Personally, if I didn't know better I could had gotten rear ended and yes this should be a safety issue. Our family would like this issue addressed and be reimbursed for my expenses. Thank you! | Crash: No Fire: No | Unknown |
| Nov 2023 | STEERING,POWER TRAIN,ENGINE | My 2018 Sierra began experiencing severe shuddering while driving down the road. The dealer said it was caused by moisture getting into the transmission fluid and contaminating it. In my ownership of dozens of vehicle's this has never happened before. This formerly inexpensive minor fluid change requirement morphed into a $618.00 major surgery just to fix a problem that should have never occured. If the fluid was contaminated by moisture as the dealer explained, it's a design defect which caused it and nothing I have ever done. I am still unsure as to if the transmission or torque converter may be damaged. The manufacturer should be liable for the cost to fix this not me! | Crash: No Fire: No | Unknown |
| Nov 2023 | STEERING,SUSPENSION,POWER TRAIN | The vehicle steering wheel shudders at speeds from 40-55mph. The steering wheel shudders at 2-second intervals and is constant between those speeds. At first, I thought it might be one of the safety systems. It is not. This is unsafe and GM should be held responsible. | Crash: No Fire: No | Unknown |
| Oct 2023 | STEERING,ELECTRICAL SYSTEM,ENGINE | The electric power steering failed while accelerating into a turn from a stop at an intersection. The wheel was jerked from my hands, and the engine stalled, all electrical failed momentarily. Within a couple of seconds everything returned to normal. This has happened several times since I purchased this vehicle. Also the electrical power steering drops out quite often at low speeds, such as in parking lots. No warnings have ever been given. In May of 2021 the dealer replaced the steering rack, the problem has continued intermittently to this date. I have researched for recalls on this problem and found that GMC issued a recall for years 2014-2017, and am amazed that they could just declare the problem fixed, and leave such a dangerous problem unresolved! | Crash: No Fire: No | Unknown |
| Oct 2023 | AIR BAGS | Both passenger and driver airbags located behind front seats/where Seatbelt is located blew during a collision, seatbelt locked us in during impact,the cab of the truck filled with white smoke and smelt like an electric fire during impact. problem will be confirmed by a collision center and insurance this week. There’s a lamp warning on the dash board that says there’s a safety warning. | Crash: Yes Fire: No Towed | Unknown |