GMC Vortec Engine Design Flaw Causes Excessive Oil Consumption

Leaking coolant from a cracked intake manifold gasket is an extremely common problem on most GM vehicles made from the late 90s to the mid-2000s. Most experts agree that the problem stems from GM's 'DexCool' coolant which erodes away at the intake manifold gasket

From 2010 to 2013, GMC’s 5.3L V8 Vortec 5300 engine has a higher than normal rate of complaints about excessive oil consumption. A lawsuit blames a design change that was made to improve the engine’s overall performance. As part of that change, owners believe defective piston rings allow oil to seep into the the engine’s combustion cylinders and burn off early.

The Vortec Oil Consumption Lawsuit

In December 2016, a Minnesota lawsuit accused GM of selling an engine with multiple defects.

The lawsuit says GM 5.3L oil consumption problems are caused by defective piston rings, PVC systems and “active fuel management” (AFM) systems that cause the spark plugs to wear out prematurely and the engines to experience all kinds of malfunctions

GM made changes to their Vortec 5300 engine design in 2007 in an effort to improve performance. However, the plaintiffs believe oil is burning off in the combustion chamber due to:

  1. Defective, low-tension oil rings which allow oil to seep into the chambers
  2. A new PCV system which sucks oil through the intake and into the combustion chamber

The plaintiffs point out that GM has issued multiple TSBs regarding oil consumption complaints.

According to the complaint, GM must have known about oil consumption problems in the 5.3L engines because on September 28, 2010, the automaker issued technical service bulletin (TSB) 10-06-01-008A addressing engine oil consumption in its 2007-2008 models. Then on January 3, 2013, GM issued another bulletin (10-06-01-008G) concerning oil consumption problems in 2007-2011 models.

In addition, the system used to monitor oil levels is thought to be defective because instead of monitoring the actual levels it monitors engine conditions to calculate “expected deterioration in oil quality.” Unfortunately that calculation is off and can result in the “check engine” light coming on too late.

Case Dismissed in 2017

While the original class-action orignated in Minnesota, the case eventually found its way to the U.S. District Court, Northern District of California.

In August 2017, a judge dismissed the case while brushing aside many of the plaintiff’s arguments.

  1. Despite the claims that the oil-level monitor was defective, the judge said the owners should have received warnings about low oil pressure.
  2. Despite the claims that defective piston rings are to blame, the judge said the owners didn’t have a proper explaination for the excessive oil consumption.
  3. Despite the TSB evidence, the judge says none of those TSBs specifically mention problems with piston rings.

The plaintiffs, who were represented by Andrus Anderson LLP, Grant & Eisenhofer P.A., and Beasley, Allen, Crow, Methvin, Portis & Miles, P.C. were given the chance to ammend their complaints.

Case Re-Opened in 2018

The plaintiffs amended their complaints in 2018, claiming the oil pressure warning systems are defective and can lead to early engine failure.

The plaintiffs allege GM switched to a standard oil sensor in later model years, proving that the previous system based on “expected deterioration in oil quality” was faulty and dangerous.

GM says the same arguments that got the case dismissed before, should also apply here. The case is pending.

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