NHTSA escalates GM 6.2L L87 V8 engine probe to Engineering Analysis covering ~997,743 trucks and SUVs

Here’s the short version: federal regulators aren’t convinced that GM’s fix for its 6.2-liter V8 actually fixed anything. NHTSA just bumped its investigation up to a full Engineering Analysis, and it now covers close to a million GM trucks and SUVs. If you own one of these vehicles, that’s not a paperwork problem. That’s your engine possibly quitting on you while you’re driving.

What actually fails inside these engines

The engine in question is GM’s L87, the 6.2-liter V8 that shows up across the truck and full-size SUV lineup. The problem lives deep in the bottom end of the motor — the connecting rods and the crankshaft.

Here’s the plain version. Your connecting rods tie the pistons to the crankshaft. The crankshaft is the big spinning shaft that turns all that up-and-down piston motion into the rotation that eventually moves your truck. Those parts take an enormous beating every second the engine runs. When a rod or the crank has a defect, it can let go. And when it lets go, it doesn’t do it politely. You get what the filing calls catastrophic engine failure — metal comes apart inside the block, and the engine is done.

From the driver’s seat, that means sudden loss of motive power. The engine can quit with no warning. If that happens while you’re merging, towing, or sitting in a fast-moving lane, you’ve got a dead truck and traffic behind you. That’s the crash risk NHTSA is worried about, and it’s a legitimate one.

Why the investigation got bigger, not smaller

GM already acknowledged the defect. In 2025 the company issued Recall 25V-274 over the connecting rod and crankshaft problems. The remedy went like this: a dealer inspects your engine, and based on what they find, you either get an oil-viscosity change to 0W-40 or a full engine replacement.

That’s a big spread. An oil change is a cheap afternoon. An engine replacement is a major repair. The idea behind the thicker 0W-40 oil is that it gives the bearings a better protective film, which is supposed to help the engines that aren’t already damaged survive.

The problem is what happened next. Regulators kept getting reports of engines failing even after the recall repair was performed. In other words, trucks that had already been “fixed” were still grenading their engines. That’s the thing you don’t want to see after a recall. It suggests the remedy may not be catching every bad engine, or that the oil change alone isn’t enough to save some of them.

So NHTSA moved. It opened Recall Query RQ26001 in January 2026 to look at whether the recall was working. Then, on August 20, 2026, it escalated to Engineering Analysis EA26005. That analysis now covers roughly 997,743 vehicles from the 2021 through 2026 model years. An Engineering Analysis is a deeper, more serious phase of a federal investigation — it’s the stage where regulators dig into whether a recall remedy is actually adequate, and it can lead to a demand for a better fix.

What this means if you own one

If you’ve got a 2021-2026 GM truck or SUV with the 6.2-liter L87 V8, here’s how I’d handle it.

1. Run your VIN. Go to NHTSA’s recall lookup and enter your VIN to see whether Recall 25V-274 applies to your specific vehicle. Don’t assume you’re clear because you haven’t gotten a letter. Check the number yourself. You can also keep an eye on your 2021 Chevrolet Silverado 1500 hub as this develops.

2. Don’t wait on the recall repair. If your truck is covered, get the dealer inspection done. Even if the remedy turns out to be just the 0W-40 oil change, that’s the current official fix, and you want it on record that you had it performed.

3. Take any bottom-end noise seriously. A knock, a ticking that gets worse, low oil pressure warnings, any rough running — that’s not something to drive through and hope on. These failures happen in the rods and crank, and by the time you hear it, damage is often already done. Get it looked at fast.

4. Document everything. This is the big one given where the investigation stands. Save your recall paperwork, your inspection results, your repair orders, and the dates. If your engine fails after you’ve had the recall work done, that record is exactly what NHTSA is investigating right now. Keep receipts and mileage. Write down what the truck was doing when it failed.

5. Know that a recall repair is free. Recall work doesn’t come out of your pocket. If a dealer tries to charge you for the 25V-274 inspection or remedy, that’s not how this works. And if the Engineering Analysis leads to an improved remedy, GM would be on the hook for that too.

My honest take

The part that should get your attention isn’t that GM issued a recall. Recalls happen. The part that matters is that engines are reportedly still failing after the fix. That’s why NHTSA didn’t close this out — it went the other direction and escalated to EA26005.

What that tells you as an owner is that the 0W-40 oil change may not be the final answer for this engine. Regulators are openly questioning whether the current remedy is adequate, and until that analysis wraps up, nobody’s promising you the problem is solved. So do the recall work, but don’t treat it as a guarantee. Watch your oil pressure, listen to your engine, and keep every piece of paper. If your motor lets go after the repair, you want to be the owner who can prove exactly what was done and when.

Sources: GM-Trucks.com and CleverDude.