2017 GMC Sierra 1500 problems

Filed Nov 2, 2026 · Transmission · LA

I am submitting this complaint to bring attention to a potential widespread engine defect involving GM's 6.2L engines, specifically the use of replacement crankshaft Part Number 12732518 in engines that were not originally equipped with the L87 engine. Approximately one year ago, I completed a second engine replacement on my 2017 GMC Sierra equipped with the 6.2L L86 engine. My original rebuilt engine failed after GM supplied a replacement crankshaft that was determined to be out of specification. Following that failure, I had to go through the expense and labor of rebuilding the engine a second time. The concern is that GM discontinued the original L86 crankshaft, Part Number 12623492, and supplied Part Number 12732518 as its replacement. My understanding is that Part Number 12732518 is also used in the L87 6.2L engines that are currently experiencing widespread engine failures and have drawn the federal safety agency's attention. After installing the replacement crankshaft, my L86 engine experienced a failure consistent with the failures being reported in L87-equipped vehicles. This raises a serious concern that the replacement crankshaft may share the same underlying defect or contribute to the same failure mechanism affecting the L87 engines. I am resubmitting this complaint in light of the federal safety agency's recent efforts to obtain additional information from General Motors regarding the 6.2L engine failures. I believe this information is important to the investigation because the potential defect may not be limited to vehicles originally manufactured with the L87 engine. I strongly urge the federal safety agency to investigate whether GM's replacement crankshaft, Part Number 12732518, creates the same engine failure risk when installed in L86 engines. Any investigation, recall, or corrective action should consider not only vehicles originally equipped with the L87 engine but also vehicles that received replacement engines or replacement crankshafts Part Number 12732518.

Filed Nov 2, 2026 · Electrical · 56,584 miles · OK

The contact owns a 2017 GMC Sierra 1500. The contact stated that while driving 10 MPH and attempting to make a turn, several warning lights illuminated and the trailer braking system message was displayed. The vehicle lost motive power. The contact stated that while attempting to start the vehicle, the vehicle started; however, the failure was persistent. The dealer was made aware of the failure. The vehicle was taken to the dealer; however, the failure had not been diagnosed. The contact stated that the failure was a known failure with the vehicle. The manufacturer was contacted, and a case was filed. The failure mileage was approximately 56,584.

Filed Oct 16, 2026 · Brakes · LA

Brakes make a flutter noise and pedal becomes hard while in drive through line or at a red light or any place that requires constant brake application for an extended period of time

Filed Sep 18, 2026 · Transmission · 140,000 miles · MS

The contact owns a 2017 GMC Sierra 1500. The contact stated that while driving approximately 30 MPH to 50 MPH, the vehicle shuddered and made a shuddering sound while shifting between gears. Additionally, the contact stated that the engine lifters and camshaft were previously replaced. The contact associated the failure with the federal safety agency Campaign Number: 25V274000 (Engine and Engine Cooling); however, the VIN was not included in the recall. The traction control warning light was intermittently illuminated. The manufacturer was notified of the failure by phone and informed the contact that the VIN was not included in the recall. The contact was referred to a dealer to determine whether the failures were associated with a recall for coverage consideration. The contact stated that a coworker's vehicle experienced an identical transmission failure, and a transmission specialist diagnosed that issue as a torque converter failure. The failure mileage was approximately 140,000.

Filed Sep 11, 2026 · Engine, Transmission · OR

The catastrophic power failure with no warning on my 2017 GMC Sierra, at 87450 miles completely contaminated the engine oil cooling lines with metallic debris and fractured structural mounts. The servicing dealership replaced the transmission but is refusing to remediate the engine line contamination without out-of pocket payment. The vehicle cannot be safely operated without causing terminal engine failure on the highway, creating a imminent mechanical and traffic safety hazard.

Filed Aug 28, 2026 · Engine · LA

I had an engine rebuilt completed on my L86 2017 GMC 6.2. After the repair, the engine failed due to the crank shaft on the engine being oversized which is the same problem that GM is having with the L87 engines. When the crank was ordered from the dealer for my L86, the only part number for the crank that was available was the new part number that was being used in the L87. Seems the same cranks were used in both engines and this recall on the L87 should be extended to anyone that had a rebuilt complete. Me and my family were left on the side of the road for a few hours which endangered our lives. The problem was determined by an independent service center and was fixed by the purchase of new parts and aftermarket bearings for the crank to allow the oil to enter the crank properly. There were no warning signs. Was driving down the road, started to hear a noise and then the engine started to over heat so that is when I stopped and called a wrecker.

Filed Jul 29, 2026 · Acceleration · TX

When I accelerate the vehicle, the gears shifts every 10mph when it shouldn’t. It does it all the way up to 60mph. It has been an on going problem since we got the truck

Filed May 13, 2026 · Electrical, Visibility · MN

Truck was started using auto start and I drove roughly a mile down the road smelt burning and looked in the back seat, I saw smoke and promptly pulled to the side of the road shut the vehicle off then I heard a loud pop and saw the back drivers side window shattered.

Filed May 4, 2026 · Wheels · MI

Dear Sir, I currently own a 2017 GMC Denali that had a potentially catastrophic failure with one of the alloy wheels that are on my vehicle. Mileage about 110,000 I recently went to have new tires installed on my vehicles when the tire shop manager came from the work area and said that he could not put a new tire on my one wheels. The reason the tire store could not put a tire on that wheel is because two of the spokes on the alloy wheel were broken. There were three spokes between the broken spokes. The are 12 spokes on the wheel and the two broken spokes were non adjoining. They were not next to each other. There were good spokes between the broken spokes. With a close inspection of the wheel there is no scuffing or impact damage to the wheel either on the outside of the wheel or the inside that would cause this failure. The spokes just cracked. The fact that the two broken spokes are not next to each other would seem to indicate that this was a manufacturing defect. I am writing to go on record of this failure of the alloy wheel on my truck. If someone would like to inspect the wheel, please contact me to arrange for a time to look at it. I have attached pictures of the wheel with the broken spokes. Regards, [XXX] You can see the cracked spokes at the 12:00 and 7:00 position on the wheel towards the center of the wheel. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Apr 19, 2026 · Engine · CT

I drive this vehicle on higher speed roads to work everyday. Roads also used by large tractor trailers and like larger vehicles. I was told by dealer that I had broken exhaust manifold studs at a previous oil change. While driving the truck it seemed to lose power for a short time but I was in traffic and assumed the loss of power at that time was related to a possible exhaust leak.I scheduled a appointment to have the repairs addressed. When I picked up the vehicle I was told that there was a ticking noise in the top of the motor. They stated it was the lifters and needed to be repaired for $7136 dollars. I researched the problem and found out how big of an issue this is specifically for the owners of the 6.2l (L86) engine. Highly concerned I schedule the repair and dropped the vehicle off. Shortly after the dealer called and stated the vehicle had bent push rod collapsed lifters damage to the cylinder head, camshaft and worn camshaft bearings now cost are $14350 or replace engine for $17000. I chose to replace top end. The next day I was called back and was told the bearing on the cam journals were down to brass and I would need new engine. Cost in just 24 hours not are $22000. This vehicle was maintained by this dealer also for all fluid changes. The belief is all the failures were related to the active fuel management system. (going from 8 to 4 cylinders ).