Dive Brief:
- The National Highway Traffic Safety Administration's Office of Defects Investigation opened a safety probe on Jan. 16 for an estimated 877,710 General Motors vehicles after receiving reports of connecting rod bearing failures that have led to catastrophic engine damage in some cases.
- The vehicles include model year 2019-2024 Chevrolet Silverado 1500 and GMC Sierra 1500, and 2021-2024 Chevrolet Tahoe, Suburban, GMC Yukon and Cadillac Escalade SUVs equipped with L87 6.2L V8 engines.
- The probe comes after the NHTSA’s ODI received 39 complaints and additional field reports alleging engine failures, some of which have occurred without any prior symptoms noticed by drivers.
Dive Insight:
The potential for engine failures poses a safety risk, as a sudden loss of power may increase the risk of a crash resulting in injury and or property damage, according to the NHTSA.
The preliminary evaluation aims to determine the scope and severity of the problem, and to fully assess any potential safety-related issues. If the ODI determines that engine mechanical problems pose a significant risk to safety, GM may be required to issue a major recall for some of its best-selling vehicles.
GM’s L87 V8 engine, which launched in 2019, is a standard design featuring overhead valves, a forged steel crankshaft and connecting rod bearing caps made of cast nodular iron. Since the 1990s, cast nodular iron has been the preferred material in a growing number of applications in the automotive industry due to its high strength, castability and machinability.
However, nodular iron is prone to issues such as surface defects and micro shrinkage pores that can lead to cracks. Cast or forged steel isn’t as susceptible. But whether or not these surface defects can reduce component service life has not been fully investigated, according to a 2019 report from Science Direct.
In November, the NHTSA also opened an investigation involving Honda Motor Co. after receiving 173 reports of connecting rod bearing failures on 2016-2020 Honda vehicles equipped with six-cylinder engines. The ongoing probe covers approximately 1.4 million vehicles.
The potential engine problems are the second major mechanical concern for some of these popular GM nameplates, including the 2020-2022 Silverado 1500 and GMC Sierra 1500. Last October, GM issued a recall for up to 462,000 trucks and SUVs equipped with diesel engines over transmission control valves that are susceptible to excess wear over time, resulting in harsh shifting, or in rare cases cause the rear wheels to lock up while driving.
