For 1990-2009 cars

# Info - Engine Crankcase Flush

Subject: | Engine Crankcase Flush

Models: | 2003 and Prior GM Cars and Trucks

| 2003 HUMMER H2

| 2003 and Prior Isuzu Light and Medium Duty Trucks

| with Gasoline Engines

General Motors is aware that some companies are marketing tools and equipment to support engine crankcase flush procedures. GM does NOT endorse or recommend crankcase flushing for any of its gasoline engines. Analysis of some of the materials used for crankcase flushing procedures indicate incompatibility with GM engine components and the potential for damage to some engine seals and bearings. Damage to engine components resulting from crankcase flushing procedures is not covered under the terms of the New Vehicle Warranty.