A shop teardown of GM’s troubled L87 V8 found a bent pushrod

Dave’s Auto Center, an independent engine builder, tore down a failing General Motors L87 6.2-liter V8 on YouTube and found a bent pushrod, a worn lifter and a damaged camshaft lobe. The builder believes the lifter rotated 180 degrees in its guide, and he has proposed a software change to the oil pump as a possible fix that is still untested.

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GM has not adopted the idea, and the teardown covers a single engine. It still lands in the middle of one of the most closely watched reliability fights in the truck market, with a federal probe and consolidated lawsuits already open. Autoblog describes the L87 as one of the most problematic modern truck engines, citing failures, recalls and lawsuits, and the video is the builder’s attempt to find new evidence for owners whose engines do not qualify for replacement.

Lifter retainers and polished bearings

According to Autoblog’s October 16 report, the builder believes the lifter turned in its guide because plastic retainers failed to hold it in place. A broken lifter could have sent metal debris through the engine, which might explain damage to the number-one main bearing. Several connecting-rod bearings also showed polishing in unusual spots, which he reads as metal-on-metal contact and as evidence that the oil film disappears when the bearings need it most.

He suspects a combination of crankshaft surface problems and the variable-displacement oil pump is the root cause. The same report adds a caution that a single teardown cannot say whether the oiling trouble or the lifter damage came first, or whether either explains every L87 failure.

The proposed oil pump fix and its limits

The proposal is to reprogram the variable oil pump so it holds oil pressure at idle and light load. Autoblog says the pump currently lowers pressure to save fuel, which the builder thinks leaves bearings exposed. The plan is to run modified engines on a dynamometer and then disassemble them to check for bearing wear and metal debris. He is also considering stronger lifter retainers to prevent the lifter damage.

The goal is a solution for owners whose engines do not qualify for replacement under GM’s current diagnostic rules. Nothing in the report suggests GM has tested or endorsed the pump change, and the author states plainly that the fix has not been tried.

NHTSA’s probe and the lawsuits around the engine

The teardown arrives against a heavy backdrop. Autoblog’s coverage of the August 22 NHTSA action says the agency’s Office of Defects Investigation opened Engineering Analysis EA26005 covering 997,743 vehicles, all 2021 to 2026 GM models with the L87, including the Silverado 1500, Tahoe, Suburban, Sierra 1500, Yukon, Yukon XL, Escalade and Escalade ESV. The report counts 499 complaints about failures after a recall remedy, and 6,050 engine-failure incidents overall: 473 complaints on vehicles given thicker oil and 26 on vehicles with a full engine replacement, both under recall 25V-274. The agency also received 191 reports of failures in engines built after the production period cited in the recall, and the report lists at least one crash or fire and one injury.

GM attributes the problem to manufacturing and quality shortcomings at a supplier, while an independent analysis cited in the same report points to microscopic ridges on the crankshaft that cause oil pressure swings and damage connecting rod bearings. GM previously argued the failure rate was about 3 percent. That diagnosis rhymes with the builder’s own suspicion about the crankshaft surface.

The legal track runs in parallel. According to Autoblog’s lawsuit report, NHTSA received more than 1,000 complaints before the recall announced in April 2025, which covered almost 600,000 trucks and SUVs. A federal judge consolidated ten or more related suits under the Powell case, and plaintiffs argue that GM’s repair, a change in engine oil specification, is insufficient to correct the defects in the engines.

New V8s on the way for 2027

GM’s answer is a new engine family. The company is introducing sixth-generation small-block V8s for the 2027 Silverado 1500 and Sierra 1500: a 5.7-liter L76, which replaces the 5.3-liter V8, rated at 402 horsepower and 428 pound-feet, and a 6.6-liter L78 at 481 horsepower and 501 pound-feet, according to Autoblog’s engine lineup feature. Cylinder deactivation carries over to the new engines, and Autoblog says the lifter issue is worth watching but does not prove the new engines will fail the same way.

A June report discussed in Autoblog’s piece on GM’s reputation repair says the company reportedly plans tighter quality control for key components, with some processes possibly moving in-house, and that GM invested $1.3 billion in propulsion plants for the new engine. The article’s own verdict was that only time will tell whether those changes work. For owners of the roughly one million L87 vehicles under review, the teardown offers a theory, not a remedy.

This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.

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