2017 GMC Sierra 1500: engine failure

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 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 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 ).

Filed Jan 28, 2026 · Engine · LA

My L86 Engine had 250,000 plus miles and the engine went out. So we decided to rebuild the engine due to the truck being paid off and the cost of a new engine is much cheaper than a new truck. After the first rebuild the engine last around 10K miles. We pulled the engine back apart to find out that the crank bearings were shot along with the brand new GM crank that was purchased. After doing research, there was no enough clearance between the GM bearings and the GM crank. Basically the same issue that the L87 is having. After doing more research it determined by the part number on the crank and the part number GM provides on their website that the L86 and the L87 (engine with current recall) take the same crank. Therefore my L86 due to GM only making the L87 crank now and it replaces the original L86 crank we had to replace the engine a second time. I believe this relevant to all the L87 issues and any L86s that are being rebuilt. We ended up having to purchase aftermarket crank bearings to get the correct clearance on the second new GM Crank that was purchased. Truck is now running good now.

Filed Oct 29, 2025 · Transmission · 128,177 miles · NC

The contact owns a 2017 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the accelerator pedal was depressed; however, the vehicle failed to accelerate as intended. No warning lights were illuminated. Additionally, the RPM increased quickly. The contact stated that the failure occurred while driving on a busy highway. The contact drove the vehicle across a four-lane highway to get the vehicle to the shoulder of the road. The contact stated that the transmission had seized. The vehicle was towed to an independent mechanic, where the vehicle was diagnosed with transmission failure. The contact was informed that the transmission needed to be replaced. The vehicle was repaired. The manufacturer was made aware of the failure but provided no assistance. The contact referenced an unknown recall with a similar failure description; however, the VIN was not included. The failure mileage was approximately 128,177.

Filed Sep 18, 2025 · Steering · 118,000 miles · TX

The contact owns a 2017 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed and coming to a stop, the steering wheel seized. There was no warning light illuminated. The contact stated that while attempting to make a turn, the steering wheel became difficult to maneuver. The dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 118,000.

Filed Jul 27, 2025 · Engine, Suspension · NC

i have 2017 gmc sierra 1500 6.2l engine i have maintain my service on this vehicle and now facing a complete engine failure due to the poor design of the engine by gmc. i have spoken with alot people and dealer mechnics and they all agree gmc and chvrolet know that this is a bad design but refuse to acept responsiblity for it. there are tousands of people with this same issue we cant fight this on our own we need your help please.

Filed Jun 19, 2025 · Engine · TX

Lifters and rollers failed. Vehicle is at a repair facility and it has been confirmed that the rollers on the cam seized causing metal shavings to build up in the oil. No symptoms or warning lights showed up before the problem was identified.

Filed May 6, 2025 · Engine · NH

My truck is currently experiencing the connecting rod and/or crankshaft engine components that may have manufacturing defects that has lead to engine damage and engine failure. My truck is currently being looked at a shop for this exact issue. GM recently recalled more than 597,000 vehicles due to engine failures, according to you, the federal safety agency. The recall however only lists vehicles within the years of 2021-2024. My vehicle has the same engine 6.2L V8 gas as the recall and I don't find it a coincidence that I have the same EXACT engine experiencing the same EXACT issue! I attempted to speak to GM but they just kept saying my vehicle is not listed on the recall and refuse to investigate this. I included my conversation with them.

Filed Apr 1, 2025 · Engine · 60,000 miles · IL

The contact owns a 2017 GMC Sierra 1500. The contact stated that on four separate occasions while driving at highway speeds, the vehicle shut off with the check engine warning light illuminated. The contact stated that after each failure, the vehicle was towed to a dealer and the contact was informed each time that the failure was related to the active fuel management system. The manufacturer was notified of the failure after the first failure and the contact was informed that the repair would be covered under warranty. The contact stated that each time that the vehicle was towed to a dealer, the lifters and pushrods were replaced under warranty; however, the failure returned almost a month after each repair. After the most recent failure, the dealer pushed the manufacturer to replace the engine. The vehicle was repaired; however, the contact expressed a fear of driving the vehicle due to the repeated failures. The failure mileage was approximately 60,000.

Filed Jan 30, 2025 · Engine, Transmission · VA

Diving my 2017 GMC SIERRA 1500 down the road and all of a sudden it had a big bang in motor,luckily only going 35 miles an hour. Had a slight tick in engine which I had gotten after most recent service visit, and had scheduled to take back to dealer. When I had checked it with a scanner, it only showed a P0700/P0711 code which was for transmission, otherwise no other lights or codes until that day when check engine light came on. Immediately stopped driving and pulled in parking lot and had car towed to dealer that day, [XXX]. They had called me back on [XXX], and said that they had to go further into engine for diagnosis, for extra charges. They called back next day and said that there was a camshaft failure that led to bent rod and metal in engine. Only fix was to replace engine. I then went and talked to them about cost and cause of failure, which is what I previously have stated. I then put in a call to GMC CUSTOMER CARE about the issue, and what they could do to help with issue, because no engine should fail with that few miles on it. Stated also that I had bought vehicle used with factory warranty still on it , and had all service since done at a GMC DEALERSHIP, and that they had all my records. And also, that the previous owner more than likely had all service done at a GMC dealership since it was all under warranty at the time. My service request with them is number [XXX]. My basis is on TSB Bulletin No: 20-NA-142 and Bulletin No: 15-06-01-002M . Which shows that GMC Corporation was aware of issues. At moment I am awaiting response from GMC. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)