He goes by michaelincognito on Reddit’s r/gmcsierra, and what started as a routine recall visit turned into something much messier: a truck that won’t run, a service advisor who’s nowhere to be found, and rental car bills piling up.
He’d picked up his Sierra AT4X back in November 2024. Then, around mid-2025, a recall notice for the L87 engine showed up, so he brought it in for a PicoScope diagnostic. The dealership didn’t find anything obviously wrong at the time. They swapped in 0W-40 full synthetic oil, extended the powertrain warranty, and sent him off, at least for the moment.
On March 28, he heard a ticking noise under the hood while driving his family to breakfast. He limped home. The next morning, the truck would not make the 15-mile drive to the dealer. He called GMC Roadside Assistance and had it towed.
The Diagnosis
The service advisor called back within an hour, according to the Redditor. It was the lifter failure associated with the L87 6.2-liter V8. The engine needed a full replacement. The advisor estimated the engine would arrive by the end of that week, with repair completion by mid-April. The owner asked for a loaner. He was told none were available.
That was March 30. As of April 27, the truck had been in the shop for 30 days. The engine had not arrived. The advisor had stopped returning calls. And the owner was still driving his wife's car to work.
"I called back on Monday, April 6th at 2:57 p.m.," he wrote. "I asked about the status and was told an engine had not arrived yet, but should be coming in at any time. I asked for a loaner again and was told they did not have any."
He called again on April 9. Same answer. He visited the dealership in person. Same answer. He asked if he could rent a car and be reimbursed. The advisor told him Enterprise "used to do something with GMC, but I don't think they do that anymore." The advisor promised a callback before 5 p.m. He never called.
The Escalation
On April 21, the owner called GMC's regional customer service line. A case worker gave him a case number, promised an update by the end of the week, and authorized a $44-per-day rental reimbursement through Enterprise. As of April 27, the callback had not come. The $44 figure covers roughly half the cost of a compact sedan rental in his area, an inferior replacement for the AT4X, but enough to get to work.
"I am beyond upset with GMC right now and will likely not do business with them again," he wrote. "I understand stuff happens, and I get that I am in a long line for a replacement engine, but this whole situation has been handled incredibly poorly in every way from the start."
The Scale of the Problem
The owner's failure is not an isolated incident. General Motors recalled more than 877,000 vehicles in April
2025 over a manufacturing defect in the L87 6.2-liter V8's connecting rods and crankshaft. NHTSA Campaign Number 25V-274 covers 2021–2024 Chevy Silverado, GMC Sierra, Tahoe, Suburban, Yukon, and Cadillac Escalade models. According to the NHTSA filing, GM identified 28,102 field complaints or incidents potentially related to the defect, including 14,332 involving loss of propulsion, 12 crashes, 12 injuries, and 42 fire allegations.
The recall remedy is bifurcated. Dealers inspect the engine. If it passes, the technician drains the 0W-20 oil, installs heavier 0W-40 full synthetic, replaces the oil cap, and hands the owner a new manual insert. If it fails, the engine gets replaced. The owner in this case had already received the oil change and warranty extension during his recall visit, and the engine failed anyway.
A commenter on the Reddit thread identifying as a former GMC service department employee put the failure rate at 3 percent, roughly 30,000 engines out of more than 600,000 units sold. That commenter also warned that replacement engines are failing, too. "With the number of replacement 6.2 lockups in the service bay after replacement," Sixgunfirefight wrote, "when it does come in, don't plan your weekend around it leaving the bay under its own power."
The Legal Landscape
In March 2026, a federal judge consolidated multiple class action lawsuits into a single 389-page complaint targeting the L87 engine. The litigation, filed in the U.S. District Court for the Eastern District of Michigan, alleges the recall remedy is "egregiously inadequate" and notes that failures often occur shortly after dealers sign off on the oil-change repair. One owner reported that GM may be preparing to replace every L87 engine in Silverado and Sierra trucks, though the company has not confirmed that.
NHTSA opened a second investigation in January 2026 after owners continued reporting failures in vehicles that had already received the recall fix.
The Reddit thread also surfaced a 2023 Customer Satisfaction Program, CSP N232413430, addressing "oversized lifter bores" in certain 2023 Sierra, Yukon, Silverado, Tahoe, and Suburban units. That program instructed dealers to replace the entire engine, but it was not a formal safety recall and only covered specific VINs.
The Dealer Problem
Multiple commenters on the Reddit thread suggested the owner's frustration was as much about the dealership as the engine. "This is 95% on the dealer and not on GM," wrote beaglewelding. "My warranty work with GM has been absolutely stellar. But again. It's the dealer you pick."
That distinction may matter to GM's lawyers, but it does not help the owner. He bought the truck at a dealership two hours away and had it towed to the one in his town. Neither location has delivered an engine, a loaner, or a straight answer in 30 days. When he mentioned a buyback to the service manager on April 27, an engine was suddenly invoiced, and he was moved to the front of the line.
"It was either a remarkable coincidence," he wrote, "or that statement seemed to get the ball rolling."
What It Means
He is paying a car note, insurance, and subsidizing a rental because GMC's $44-per-day reimbursement does not cover the actual cost of a replacement vehicle. The recall he completed in good faith did not prevent the failure. And the dealer network tasked with fixing it appears overwhelmed by demand.
For prospective buyers, the case is a reminder that passing a recall inspection does not guarantee immunity. The 0W-40 oil switch and extended warranty are GM's current defense, but the class action alleges those measures are insufficient, and the post-recall failure data NHTSA is now investigating suggests the problem may be deeper than lubrication viscosity. It also fits a broader pattern of declining reliability that has some longtime Sierra owners questioning whether the brand's modern trucks can match the longevity of earlier generations.
GM has not publicly stated whether it will expand the recall to include 2025 model years or whether it will pursue a more comprehensive fix than oil changes and spot replacements.
Image Sources: GM Media Center
About The Author
Noah Washington is an automotive journalist based in Atlanta, Georgia, covering sports cars, luxury vehicles, and performance culture. His reporting focuses on explaining the engineering, design philosophy, and real-world ownership experience behind modern vehicles.
Noah has been immersed in the automotive world since his early teens, attending industry events and following the enthusiast communities that shape how cars are built and driven today. His work blends industry insight with enthusiastic storytelling, helping readers understand not just what a car is, but why it matters.
Noah is also a member of the Southeast Automotive Media Association (SAMA), a professional organization for automotive journalists and industry media in the Southeast.
His coverage regularly explores sports cars, luxury vehicles, and performance-driven segments of the automotive industry, including the evolving culture surrounding Formula Drift and enthusiast builds.
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