General Motors has been hit with a judgment of $102.6 million in a class action lawsuit brought by customers in California, Idaho and North Carolina who purchased 2011 to 2014 Chevrolet and GMC vehicles equipped with the company’s LC9 5.3-liter Vortec V-8 engines.
The lawsuit alleges the LC9 5.3-liter Vortec engines delivered in 2011-2014 Chevrolet Avalanches, Silverados, Suburbans and Tahoes as well as 2011-2014 GMC Sierras, Yukons and Yukon XLs manufactured on or after Feb. 10, 2011 contain an inherently defective piston assembly, which causes unusual and excessive wear.
The plaintiffs argued worn piston rings caused excessive oil consumption. The oil consumption in turn resulted in a variety of engine problems including spark plug fouling, rough running, check engine lights and permanent engine damage requiring engine replacement. A GM engineer is reported to have testified that the company developed a cleaning process for the pistons, but that it was ineffective over time.
If the ruling stands, each of the 38,000 plaintiffs in the class action will receive $2,700 in compensation. GM has issued a statement stating that the verdict was not supported by evidence and that the company plans to appeal the judgment.
The case identifier is Siqueiros et al v. General Motors LLC, U.S. District Court, Northern District of California, No. 3:16-cv-07244.
Additional lawsuit alleges faulty cylinder deactivation system
In addition to the piston lawsuit, GM is facing suit from unhappy customers who purchased Buick, Cadillac, Chevrolet and GMC vehicles equipped with the Active Fuel Management (AFM) cylinder deactivation system.
That case identifier is Danny Harrison et al., v. General Motors LLC, Case No. 2:21-cv-12927-LJM-APP, filed in the U.S. District Court for the Eastern District of Michigan.
This suit alleges the valvetrain used in the AFM system is defective, and it covers any 2014 to 2021 model year Cadillac, Chevrolet or GMC vehicle equipped with a 5.3-liter, 6.0-liter or 6.2-liter V-8 engine equipped with AFM.
The AFM system uses 16 fuel management lifters, with two lifters covering each of the eight cylinders on the engine. The lifters open to allow fuel to flow to the cylinders, or close to prevent fuel flow when the engine management system does not need that cylinder to fire. The system is designed to reduce fuel use when possible, but to keep engine power available when needed.
The suit alleged that GM knew but did not disclose that the AFM lifters were defective, and further contends that the defective lifters can place drivers and passengers in danger because the engines may stall, lose power, or hesitate on acceleration. If the issue is left unresolved for an extended period of time, the plaintiffs argue that the entire engine can be damaged, needing an expensive full engine replacement.
The plaintiffs also allege that when the lifters fail under warranty, GM instructs its dealerships to replace the defective parts with identical components, which the suit contends are also defective. Plaintiffs are concerned that the situation is not resolved when the vehicles pass out of warranty coverage. The lawsuit contends that this was a breach of the implied warranty of merchantability and of state consumer protection laws.