Engine Oil
For diesel engine vehicles, see “Engine Oil” in the Duramax Diesel Supplement.
To ensure proper engine performance and long life, careful attention must be paid to engine oil.
Following these simple, but important steps will help protect your investment:
• Always use engine oil approved to the proper specification and of the proper viscosity grade. See “Selecting the Right Engine Oil” in this section.
• Check the engine oil level regularly and maintain the proper oil level. See “Checking Engine Oil” and “When to Add Engine Oil” in this section.
• Change the engine oil at the appropriate time. See Engine Oil Life System on page 10‑10.
• Always dispose of engine oil properly. See “What to Do with Used Oil” in this section.
See also:
Four-Wheel Drive
Transfer Case
When to Check Lubricant
Refer to Maintenance Schedule on page 11‑3 to determine when to check the lubricant.
How to Check Lubricant
Electric Shift Transfer Case
A. Fill Plug ...
Bluetooth
For vehicles equipped with Bluetooth capability, the system can interact with many cell phones, allowing:
• Placement and receipt of calls in a hands-free mode.
• Sharing of the cell phone’s a ...
Brakes
Brakes stop the vehicle and are crucial to safe driving.
• Signs of brake wear may include chirping, grinding, or squealing noises, or difficulty stopping.
• Trained dealer technicians have acce ...





