Plaintiffs in the case regarding excessive oil consumption in GM's 5.3L Vortec 5300 engines have switched gears. The original case was tossed out by a judge last year, but the plaintiffs were given a chance to ammend their complaints. So they've switched their focus into a potentially defective oil pressure warning system that doesn't properly monitor oil levels and can lead to early engine failure.
The judge looking into last year's Vortec excessive oil consumption lawsuit does not seem to buying claims that the engine is defective. The case has been tossed out.
Concerning owner-reported complaints, the judge found those owners talk about excessive oil consumption but they don't specifically say what is causing the oil consumption. As for the bulletin sent to dealerships, it doesn't say anything about the oil rings and sending the bulletin doesn't mean GM believed the Vortec engines were defective.
A lawsuit has been filed on behalf of certain 2010-2013 GM owners with 5.3L V8 Vortec 5300 engines. According to the plaintiffs, changes to the engine design allow oil to enter the combustion chamber, leading to excessive oil consumption and premature engine failure.