NHTSA has opened an Engineering Analysis into continued failures of GM’s 6.2-liter L87 V8 after the automaker’s original recall remedy. The initial recall covered nearly 600,000 engines used in popular fleet vehicles including the Chevrolet Silverado 1500, Tahoe and Suburban, GMC Sierra 1500 and Yukon, and Cadillac Escalade. Engines that passed inspection were switched from 0W-20 to heavier 0W-40 oil in an effort to reduce the risk of crankshaft, connecting rod and bearing failures.

Concerns have continued after the recall work was completed. NHTSA has received 499 reports of post-recall engine failures, while GM has recorded thousands of additional reports. Failures have also been reported in replacement engines and engines produced after the original recall period. As a result, NHTSA's investigation now covers nearly 1 million engines through the 2026 model year. For fleets operating affected GM vehicles, the investigation is important to monitor because an additional recall or revised repair procedure could follow, potentially affecting vehicle reliability, maintenance planning and downtime.