Update: On October 4, 2022, a jury returned a verdict in favor of the Plaintiffs on the certified claims for the three classes. No final judgment has been entered, and no money is available to class members at this time. General Motors has filed post-trial motions contesting the verdict and intends to appeal if the Court denies GM’s post-trial motions and enters judgment. A copy of the Jury Verdict is available here. Please continue to check this website for updates.

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Nature of the Case

The Court certified a class action lawsuit and that your rights may be affected. The lawsuit alleges defects in certain 2011-2014 Chevrolet Avalanche, Silverado, Suburban, Tahoe, and GMC Sierra, Yukon, and Yukon XL vehicles equipped with Generation IV LC9 5.3 Liter V8 Vortec 5300 engines (“LC9 Engines”). Judge Edward M. Chen of the United States District Court for the Northern District of California is overseeing this lawsuit.  The lawsuit is known as Siqueiros et al. v. General Motors, LLC, and the case number is 3:16-cv-07244-EMC.

Am I in a Class?

The “Class Vehicles” are: 2011-2014 Chevrolet Avalanches, Silverados, Suburbans, Tahoes, and 2011-2014 GMC Sierras, Yukons, and Yukon XLs with LC9 engines and manufactured on or after February 10, 2011. Any vehicle that has already received adequate piston replacement (i.e. upgraded piston rings) is excluded from the class. Class members are all current owners or lessees of a Class Vehicle who purchased or leased the vehicle (a) in the State of North Carolina, (b) from a GM-authorized dealer in Idaho, or (c) purchased or leased in new condition in the State of California.



Option and Deadline

Your Legal Rights

Ask to be excluded 

Deadline passed

If you do not want to participate in the Class, you can exclude yourself by mailing a request for exclusion by July 7, 2022. This is the only option that allows you to retain any rights you may have against GM over the claims in this case. You must send your written request for exclusion to: GM 5300 LC9 Class Action P.O. Box 5124, Baton Rouge, LA 70821.

If you decide you do not want to participate in the Class and you do not make a timely request for exclusion as described above, you will still be bound by the jury’s verdict, should the case go to trial.

Do Nothing at this time

no deadline


If you wish to remain in the class, you do not need to do anything at this time.


Dates and Deadlines

Exclusion Deadline

July 7, 2022

Trial Date

September 14, 2022