2018 GMC Sierra 1500: sudden loss of power

Filed Sep 6, 2026 · Engine, Transmission · KY

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 going bad in the transmission were the source of it. 3 hours later the servicing was done which cost $ 474.43. She did not know if the ticking had stopped or not. I started my engine to head home and the ticking was still happening. Nothing had changed. I got home, parked and have not started the engine since to minimize any further damage. I have become aware that this year, make and model has become infamous for the engine/transmission design and parts failure which has been at the center of thousands of class action lawsuits. I have owned this vehicle since inheriting it from my late father for 2 months before he developed dementia and suffered a broken hip. I have religiously had the oil changed every three months regardless of the mileage, and this is a sealed transmission which cannot be worked on by someone but a certified GMC mechanic, which wasn't a worry because the truck's manual says doesn't need to be worked on unless there seem to be problems. Which is what I did on 9-4-26, hoping that a servicing would fix the issue. During the 5 years that I have owned this truck, I never received ANY sort of notice from GMC that might've hinted at possible Transmission Failures, though GMC has been totally aware of. Sudden power loss dangerous and unfairly expensive to drivers.

Filed Jun 11, 2026 · Engine, Transmission · AR

Vehicle Details: 2018 GMC Sierra 1500 Z72 4x4, 5.3L V8 EcoTec3 engine, VIN: [XXX] Mileage at time of incident: 220,000 miles Location: [e.g., Little Rock, Arkansas area or specific road/highway – please provide if desired] What happened: The 5.3L V8 engine’s hydraulic roller lifters failed. One or more lifters collapsed, stuck, or lost proper oil pressure/operation. This led to improper valvetrain function, causing loud ticking/knocking noises, cylinder misfires, significant loss of engine power and performance, and internal engine damage (such as camshaft lobe wear or related components). Component or system that failed or malfunctioned: Hydraulic valve lifters (camshaft followers) in the engine valvetrain, associated with the Active Fuel Management (AFM) system. The failed lifter(s) and related components are available for inspection upon request. How safety was put at risk: The engine malfunction resulted in sudden or progressive power loss and misfiring while driving. This reduced the vehicle’s ability to accelerate or maintain speed, especially in traffic or on highways, creating a hazardous situation that put my safety and the safety of other road users at risk of collision or breakdown. No accident or injuries occurred , or other symptoms prior to the failure with details recall, e.g., ticking noise timeline, misfires Has the problem been reproduced or confirmed by a dealer or independent service center? “Yes, confirmed by shop inspection” Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? [Yes] Additional notes: Repair estimate is approximately $20,000 (likely due to extent of internal damage requiring major engine work or replacement). This failure aligns with a well-documented issue in GM 5.3L engines equipped with AFM. Vehicle status parked INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Jun 2, 2026 · Brakes, Engine · NJ

Incident description: On three occasion I have had the same catastrophic Engine failure putting myself and my family along with the general public in harms way. Starting March of 2022 while driving at approximately 60 MPH on the West Shore Expressway my truck experienced a sudden and total loss of motor power. My engine stalled out and I lost my ability to safety steer and stop my vehicle. This all happened during rush hour while driving in the left lane of traffic. This sudden loss of power forced me to maneuver the vehicle to the right shoulder of the expressway across the right lane of traffic. As there was no shoulder to pull over on the left side of the highway. This created an immediate crash risk for myself and other drivers. Upon inspection at the authorized GMC dealership where I purchased the truck new, a certified mechanic determined that the engine experienced a complete failure requiring replacement or rebuilding of the engine. I paid to have the engine rebuilt at the dealership. The second instance was similar to the above incident. Once again I paid for the repair. The third instance was more dangerous as when my trucks engine failed it almost caused an accident. As of today my truck is still sitting in the dealership for over 6 months and no one from the dealership or manufacturer will give me an answer on what has to be done now. This patter of sudden repeated engine failure clearly indicates a systemic safety defect that extends beyond normal wear and tear. I urge the federal safety agency to open a defect investigation into the 2018 GMC Sierra 1500 engine systems.

Filed Mar 3, 2026 · Electrical, Steering · WI

1. Electronic power steering modular issue. My 2018 GMC SEIRRA 1500 CREW CAB JUST LOST ALL POWER STEERING. THEN WHEN I PARK IT. Assist notifications come on, ABS notices, BRAKE light stays on, trailer/tow notifications, trailer assist, parking brake, etc SUDDENLY A LOUD thump & feels like the whole truck just drops like 5” inches, settling. I cannot afford an inspection (ID theft in 2025, compromised all accts & all credit cards) BUT. It IS available as long as cost is covered by YOU !! 2. Lucky it happened in a grocery store parking lot. However not expecting power steering to go out, almost hit a pedestrian. 3. No it has not Ben inspected yet I can’t afford the bill 4. No it has not been reported what for I didn’t hit anybody and the cops in this area they could give her rats ass they don’t make a report the question you like you’re like a criminal. 5. No warnings or anything until it happened that day leaving the grocery store. There is absolutely no notification it was gonna happen. It ran fine when I parked it to grocery shop Come back out & I could barely back out to leave. I can lift up my had fatboy if needed so I’m sure turning a steering wheel…. lol Thnx a lot If I could figure out what part needs to be changed out or you could cover the parts needed. I do work in cars or have in the past, I don’t like the new ones, but this seems simple enough if I knew exactly what part I needed to pull out change out or I see that there’s recalls on previous vehicles and GMC after2020- 24 but I don’t see 2018 didn’t happen so I like to say whoever created that electronic steering can take that module along with the harness and they know exactly where they can put it don’t they I’m just saying as a used to be not sure now a GMC supporter, but I’m starting to think twice now if I

Filed Feb 28, 2026 · Transmission · SD

I’ve gone through two transmissions on my 2018 gmc sierra 1500 both times the same issue. The gears are shot, hard shifting. Vehicle is well maintained. Both transmissions one original equipment and second bought at the dealership the truck was bought both only lasted over 80000 miles. Driving the truck loss of power or torque is noticed, then a hard shifting. Checked fluid all was good not seeing metallic shavings. Then the overheating of the transmission, faulty valve replaced with aftermarket bypass and did transmission flush. But each occasion there was an incident I would’ve driving on the interstate and vehicle would lose power and almost hard stop and cause a crash. Then vehicle would only go in reverse both times the transmission gave out. The only warning light that ever came on was a transmission overheating and nothing else. I’m currently in the process of having to get another transmission because of the same issue again. Vehicle was seen by a technician and deemed the transmission was shot again.

Filed Jan 29, 2026 · Engine · 150,000 miles · TX

The contact owns a 2018 GMC Sierra 1500. While starting the vehicle, it was shaking violently, with reduced power. The vehicle was restarted and worked as designed. Upon research, the contact associated the failure with the federal safety agency Action Number: PE25001 (Engine and Engine and Cooling). The vehicle was taken to an independent mechanic who determined there was metal in the engine, and there was a misfire coming from cylinder #2. The mechanic recommended that the engine be replaced. There were loose wires from the ECM, and the failure halted after the mechanic secured the wires. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was notified of the failure. The approximate failure mileage was 150,000.

Filed Dec 15, 2025 · Engine, Transmission · SC

I have 125,000 miles on my truck. I was traveling with my grandkids in the back seat. We were going through a four way stop. My truck started tapping like a lifter issue. The next thing I know is the truck engine light started flashing and car started to shake. Then, my truck lost all power and a big cloud of blue smoke came out of the tail pipe. The truck could not be driven any further. The symptoms: engine tapping, low oil, engine light flashing, shaking, lost all movement, and a cloud of smoke We had to tow my truck to the dealer and they are still accessing the issue. All symptoms are identical to the current recall of the GMC engines.

Filed Nov 20, 2025 · Engine · NV

The injector failure in my 2018 GMC Sierra 1500 resulted in repeated misfire conditions (P0300 and P0307), causing the vehicle to lose power unexpectedly while driving. The engine would hesitate, shake, and struggle to accelerate, especially during merging or highway speeds. These symptoms created a significant safety hazard because the vehicle could not reliably maintain speed or respond to throttle input. Sudden power loss in traffic exposes the driver and surrounding motorists to an increased risk of collision, particularly during lane changes, freeway merging, intersection crossings, and passing maneuvers. The dealership confirmed internal injector failure, and the vehicle has been out of service for three months without resolution. This is a safety-critical defect that compromises vehicle controllability, stability, and safe operation on public roads.”

Filed Oct 31, 2025 · Engine, Seats · FL

I purchased a 2018 GMC Sierra 1500 6.2 Denali new. I followed all service requirements including oil changes by GM dealerships. 2025 i noticed my truck power was decreasing. Than I started to hear knocking noses. I took it to a dealership for diagnosis but they couldn't identify anything. Finally it started to skip this is when a dealership diagnose it as being an issue with the active fuel management system. They said my lifters, camshaft, and various other parts was damaged and had to be replaced. Additionally, they said it was a recall on 6.2 engines with the same identical issue but my year wasn't included. The cost to repair approximately 10,000. I really need your attention to this matter! September 10, 2025 my truck placed me and others in danger when it lose engine power. Also my engine light was on for the first time.

Filed Jul 19, 2025 · Engine, Fuel system · TN

I own a $35,000 2018 gmc Sierra 1500 6.2l V8 4x4 Denali, which is currently down due to engine failure while I was driving down the road.. never had a check engine light on the dash. Haven't had the truck a year before it quit. Rods knocking, crankshaft bearings, loss of power, high rpm with little acceleration. I could have the peddle down to the floor and would barely get to 20 mph.. the motor would jump so bad, you would think it's going to jump out the truck. I have replaced several parts on the truck, including oil pump, filter, solenoid valve sensor, fuel pump, injectors, and sensors, battery, starter a couple times. Did all that replacing for it to get worse and finally quit while driving.. I was stranded in the middle of the road.. IV reported it to the Recall people, but nothing helped. I have taken my vehicle to Express Chevrolet and they did a diagnostic test, which I provided the list they gave me below. When I took it to them, I was using Endurance Warranty, but they denied my claim due to the issues and they didn't cover them. At the time, the motor was still jumping, but smoke was coming out the tailpipe extremely bad, the truck was jerking and jumping. After replacing everything I listed, the truck got worse, started screeching and knocking loudly, loss of engine power, little acceleration. The day the motor quit on me while driving, I got the mph up to about 55-60 and it just quit, and hasn't started back since.

Filed Jun 12, 2025 · Engine, Fuel system · 133,742 miles · TN

The contact owns a 2018 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed and depressing the accelerator pedal, the vehicle failed to accelerate as intended. The message "Reduced Power" was displayed, and the RPMs increased. Additionally, the vehicle jerked, and the contact noticed that there was smoke coming out of the exhaust pipe. The vehicle was driven to the contact's residence. The vehicle was taken to an independent mechanic, where it was diagnosed that the starter, the battery, the fuel pump, the oil pump, the oil pump sensors, and the fuel injectors had failed and needed to be replaced. The vehicle was repaired; however, the failure reoccurred. The contact stated that while driving at an undisclosed speed, the vehicle stalled. There was no warning light illuminated. The vehicle was able to restart; however, the failure recurred. The vehicle was driven to the contact's residence. The vehicle was not repaired. The manufacturer was made aware of the failure, but no assistance was provided. The failure mileage was approximately 133,742.

Filed Jun 5, 2025 · Electrical, Engine · TX

Engine lifters failed. Heard ticking noise first day truck was purchased that gradually got louder but was told by gmc service shop it was normal to hear the ticking noise. Also when cruise control is on and you are decending a hill the rpms raise and you lose engine compression this will cause your speed to drop to around 20 mph and has happened nunerous times.. as well when making a turn sometimes or just driving the vehicle turns off while in motion and you have to coast to the side of the road and turn the key off and back on to start driving agsin.. the loss of power is a complete blackout no dash.. no engine nothing. As result of the lifter issue the engine also hard shifts in and out of slow gears.. I have not driven my truck in about a year and still owe 22k on it. The issues with this vehicle are the same as the recalled 6.3 v8 engines.