*Median odometer reading when the problem happened, where owners gave one. One complaint can name several problem areas.
Power train
My 2018 GMC Sierra 1500 experienced significant transmission problems that began as rough, inconsistent shifting, hesitation, and abnormal transmission behavior before eventually progressing to complete transmission failure. These symptoms were present before the transmission's ultimate failure and while the vehicle was still within its warranty period. Unfortunately, during the COVID-19 pandemic, local dealership service departments faced significant staffing shortages and appointment backlogs, making timely diagnosis and repair extremely difficult. By the time the transmission failed completely, the vehicle had exceeded the warranty's 84-month time limitation but remained substantially…
Sep 8, 2025Engine
CUSTOMER STATES: THINKS CRANKSHAFT PULLEY IS LOOSE DUE TO PRIOR WATER PUMP REPLACEMENT-CRACKSHAFT PULLEY HAS NOTHING TO DO WITH WATER PUMP REPLACEMENT. BEFORE INSPECTING/STARTING ENGINE VERIFIED OIL LEVEL-OIL LEVEL IS ON FULL MARK. STARTED ENGINE-LOUD RATTLING/KNOCKING NOISE FROM ENGINE-ENGINE HAS INTERNAL FAILURE-ENGINE REPLACEMENT IS REQUIRED. ALSO HEARING NOISE IN REAREND-CANNOT TEST DRIVE DUE TO ENGINE CONDITION SEVERAL TSB'S ON ENGINE FAILURES WITH 6.2L ENGINES. GM HAS POSSIBLE RECALLS COMING ON 2019-2024 YR MODELS. NOT SURE IF EARLIER MODELS MAYBE INCLUDED UNDERHOOD INSPECTION 1 7003186 06NS 52.50 52.50 LBR-DISC CUST SAT
Sep 20, 2026Engine
I was backing out of my garage and truck made strange noise and shut off . Tried to restart but just made ding and wouldn't turn over . Dash lights went blank. Had vehicle towed to shop and mechanic stated it was crank and connecting rods after he dropped the oil pan. I ordered new OEM engine and waiting on delivery . Been 5 weeks now since order . Vehicle only has 106,000 miles on it and have had it since 20,000 miles and all maintenance has always been done . Engine can be inspected at shop as new engine has not arrived
Aug 5, 2026Power train
Vehicle purchased Certified Pre-Owned in October of 2021 with roughly 43,000 miles. During the first service (47,598 miles) at a GM dealer I reported very hard shifts, but this issue was ignored during service. At the next servce (54,571 miles) I again reported the hard shifts and "surging" when coming to a stop but the dealer reported they were unable to replicate the issue and did not address it. At the next service (61,620 miles) I reported the issues with the transmission once again and this time they performed a transmission fluid flush/replacement, acknowledging the issue and asking me to drive for 200 miles and return if the issue was not fixed. I returned at 62,058 miles as the…
Jan 15, 2025Power train
Unknown
Aug 27, 2026Power train
I own a 2018 GMC Sierra 1500 V8 5.3 liter which is at 46, 433 miles. Over the past few weeks I have noticed the transmission having difficulty shifting in first gear and lurching, and making shuddering noises, and as well making a constant ticking noise. After an experienced mechanic had put a diagnostic system onto my truck, his system diagnosed a Transmission Lifter Failure, specifically 2 out of the 8 lifters. A few days later (9-04-26) I took my truck to a certified GMC servicing business (Patriot Chevrolet of Hopkinsville KY 270-886-1207) and had a transmission servicing done. I had told the Customer Service representative Amanda Williams about the ticking and that I thought 2 lifters…
Aug 14, 2026Power train
Within the first 3 years of purchase as a new vehicle, my 2018 GMC Sierra Denali equipped with the GM 8L90 automatic transmission developed a pronounced judder during light acceleration, resembling driving over rumble strips. The condition was first reported to an authorized GMC dealer on October 23, 2021, at 26,648 miles while the powertrain warranty was in effect. GM authorized a transmission-fluid exchange from the technical service bulletin (TSB) 18-NA-355, dated April 2020, but that repair did not provide a lasting correction. The condition continued, and in 2026 the authorized dealer diagnosed an âinternal stator issue causing judder on light accelerationâ and recommended…
Oct 23, 2021Power train
Automatic Transmission not shifting properly unable to accelerate bangs gears while shifting noises from the transmission not reported no warning lamps
Sep 1, 2025
Owner complaints are submitted to NHTSA by the public and are not verified. Shown as filed (NHTSA removes personal details); long reports are shortened.