General Motors’ 6.2-liter L87 V8 is facing a much larger federal investigation after owners reported engine failures in vehicles that had already received the company’s recall remedy.
The National Highway Traffic Safety Administration has opened Engineering Analysis EA26005, covering an estimated 997,743 GM trucks and SUVs from the 2021–2026 model years.
That number deserves attention, but it also requires an important clarification: GM has not recalled all 997,743 vehicles. NHTSA has expanded its investigation to determine whether the existing recall repair was effective and whether newer L87 engines outside the original recall period may have the same safety defect.
Nearly one million vehicles are under investigation. Nearly one million vehicles have not been recalled—at least not yet.
Which GM Vehicles Are Included in the L87 Investigation?
The expanded investigation covers certain 2021–2026 vehicles equipped with the naturally aspirated 6.2-liter L87 V8. The affected nameplates include:
- Cadillac Escalade
- Cadillac Escalade ESV
- Chevrolet Silverado 1500
- Chevrolet Suburban
- Chevrolet Tahoe
- GMC Sierra 1500
- GMC Yukon
- GMC Yukon XL
The investigation is engine-specific. Owning one of these models does not automatically mean the vehicle has an L87 or that its VIN was included in the original recall.
Owners should use the official NHTSA recall lookup or the recall page maintained by Chevrolet, GMC or Cadillac to check the exact VIN. A badge, trim level or model year is not a substitute for a VIN search.
Why Is NHTSA Investigating the GM L87 Again?
GM issued recall 25V-274 in 2025 after determining that certain L87 engines could contain manufacturing defects involving their crankshafts or connecting rods.
According to the official GM recall instructions filed with NHTSA, those defects could cause internal engine damage and complete failure. If an engine fails while the vehicle is moving, the driver can suddenly lose propulsion and face an increased crash risk.
The original recall covered approximately 597,000 vehicles equipped with engines produced between March 1, 2021, and May 31, 2024.
Dealers performed an engine inspection and applied one of two remedies:
- Engines that failed the inspection could be repaired or replaced.
- Vehicles that passed received higher-viscosity engine oil, a replacement oil filter, a new oil-fill cap identifying the required grade and an owner’s-manual insert.
GM also provided additional engine protection for affected vehicles after the recall procedure was completed.
The arrangement was intended to identify engines already showing evidence of trouble while providing additional protection for those that passed. Unfortunately, engines have reportedly continued failing after both versions of the repair.
GM inspected the engines, changed the oil recommendation for the survivors and replaced the ones that failed. NHTSA has apparently requested a longer ending.
Hundreds of Engines Reportedly Failed After Recall Service
The NHTSA Engineering Analysis reports 499 complaints alleging engine failure after the original recall remedy was performed.
Of those complaints:
- 473 involved vehicles that received the oil-viscosity change
- 26 involved vehicles that received a replacement engine
- 191 additional reports involved engines produced after the original recall window
GM reported receiving 6,953 complaints alleging post-remedy engine failure. After eliminating reports submitted to both the manufacturer and NHTSA, the agency lists 6,050 combined incidents in its summary.
The federal investigation also records one crash, one injury and no reported fatalities.
Those figures do not prove that every reported failure has the same cause. That is one reason the Engineering Analysis exists: NHTSA will examine the failures, components, production records and remedies before deciding whether the existing recall was adequate.
Why the Newer L87 Engines Matter
The original recall focused on engines manufactured through May 31, 2024. NHTSA is now investigating reports involving engines produced after that cutoff, which brings later vehicles into the review.
That does not confirm that every 2025 or 2026 L87 contains the original manufacturing defect. It means regulators have received enough reports to investigate whether the problem extends beyond the production range GM originally identified.
This distinction matters for owners of newer trucks and SUVs. A 2025 or 2026 model may have no open L87 recall when checked by VIN while still falling within the population NHTSA is studying.
An investigation can eventually produce an expanded recall, a revised repair procedure, additional testing, warranty action or no further recall at all. Until NHTSA completes its analysis, anyone claiming the outcome is already settled has developed an impressive ability to read federal paperwork from the future.
What Is the GM L87 6.2-Liter V8?
The L87 is part of GM’s modern small-block V8 family. It uses familiar pushrod architecture combined with direct fuel injection, variable valve timing and Dynamic Fuel Management.
GM rates the production L87 at:
- 420 horsepower at 5,600 rpm
- 460 lb-ft of torque at 4,100 rpm
- 6.2 liters of displacement
- Naturally aspirated induction
- Regular gasoline compatibility in GM’s industrial specification
Its large displacement and compact pushrod design also make the L87 interesting to engine builders and swap enthusiasts. The basic formula is familiar: two valves per cylinder, plenty of displacement and a package that doesn’t require an engine bay shaped around four overhead camshafts.
That does not make the current investigation an aftermarket story, however. This inquiry concerns possible factory component defects and the effectiveness of an official safety-recall remedy. An intake, exhaust system or enthusiastic ECU calibration will not negotiate improved metallurgy with a crankshaft.
Builders should establish an engine-health baseline before adding power. Pro Street’s engine-health inspection guide explains how oil-pressure testing, filter inspection, compression testing and other checks can identify problems before additional load turns them into considerably more expensive problems.
What Are the Possible L87 Failure Symptoms?
NHTSA’s investigation concerns internal failures capable of causing sudden loss of propulsion. Owners should pay attention to symptoms that may indicate serious lubrication or rotating-assembly trouble, including:
- Deep knocking that rises with engine speed
- Ticking, tapping or rattling that becomes progressively louder
- Low-oil-pressure warning
- Abnormal oil-pressure readings
- Severe vibration
- Sudden loss of power
- Engine stalling or seizure
- Metal contamination in the oil or filter
- Check Engine light accompanied by noise or power loss
- A no-crank condition following an internal engine failure
Not every tick, warning light or hesitation confirms a defective L87. Fuel, ignition, sensor, valvetrain and accessory problems can create similar symptoms. Proper diagnosis still matters.
Our guide to engine knocking noises explains the difference between combustion knock, valvetrain noise and deeper sounds associated with crankshaft or connecting-rod bearing damage.
If the red oil-pressure warning light appears while the engine is running, move somewhere safe and shut the engine off. A normal oil level does not prove that the engine has safe oil pressure.
Should L87 Owners Stop Driving?
NHTSA has not issued a universal stop-driving order for every vehicle included in EA26005. Owners whose trucks run normally and have no warning signs should check their VIN, review their service history and follow the manufacturer’s maintenance requirements.
Stop driving and arrange a tow if the vehicle develops:
- Loud internal knocking
- An oil-pressure warning that remains illuminated
- Sudden severe power loss
- Grinding or seizure symptoms
- Heavy oil leakage
- Visible metal in the oil
- A flashing Check Engine light with severe shaking
- Any condition that makes the vehicle unsafe to control
The Pro Street stop-driving guide covers the symptoms that require immediate shutdown rather than another hopeful trip around the block.
Continuing to operate an engine with low oil pressure or bearing noise can turn a repairable problem into a complete engine replacement. Internal engine parts are remarkably efficient at producing external inspection windows when sufficiently encouraged.
What Should Owners Do Now?
Owners of an L87-powered GM vehicle should take the following steps:
1. Check the VIN
Use NHTSA’s recall lookup and the manufacturer’s recall portal. Check again periodically because an investigation does not immediately create a new recall listing.
2. Confirm whether recall 25V-274 was completed
Review repair orders and dealer records. Determine whether the vehicle received the oil remedy, an engine repair or a replacement engine.
3. Preserve every service document
Keep recall paperwork, oil-change invoices, towing receipts, diagnostic reports and dealer communications. Record oil viscosity, mileage and dates.
4. Use the specified engine oil
Follow the oil specification on the current oil-fill cap, owner documentation and recall instructions for the exact VIN. Do not choose viscosity based on an online argument whose primary diagnostic instrument was confidence.
5. Report serious failures
Owners can file a safety complaint through NHTSA’s vehicle-safety portal. Include the VIN, mileage, recall-repair history, warning symptoms and supporting documentation.
6. Do not modify around an unresolved failure
Diagnose knocking, low pressure, metal contamination and unexplained power loss before tuning the engine or adding performance parts. Modifications can complicate troubleshooting without correcting a defective internal component.
Does the Investigation Mean Another Recall Is Coming?
Not necessarily.
An Engineering Analysis is a serious escalation because it allows NHTSA to examine technical data, component failures, manufacturing records and the effectiveness of the existing remedy in greater depth. It can lead to an expanded recall or a revised repair, but that result is not automatic.
The immediate questions are straightforward:
- Did engines fail after receiving the higher-viscosity oil?
- Did replacement engines also fail?
- Are the later engines failing from the same underlying defect?
- Did the original inspection reliably identify at-risk engines?
- Does the remedy sufficiently reduce the chance of sudden engine failure?
Those answers—not the size of a headline—will determine what happens next.
The Bottom Line
NHTSA’s GM L87 engine investigation now covers nearly one million 2021–2026 trucks and SUVs. The agency is examining hundreds of reported failures after recall service, including failures involving both higher-viscosity oil and complete engine replacement.
It is also investigating later L87 engines manufactured beyond the original recall window.
That does not mean every vehicle in the expanded population is defective, and it does not mean all 997,743 vehicles have been recalled. It means the federal government is no longer limiting its examination to the first batch of recalled engines.
Owners should check their VIN, preserve their records and treat knocking, oil-pressure warnings and sudden power loss seriously. GM’s 6.2-liter V8 remains an appealing engine on paper. NHTSA is now determining how many of them remain equally appealing once the paper is removed.