Coolant Level Check on a 2023 GMC Sierra 3500 HD SLE 6.6L V8 Turbo Diesel

Checking the engine coolant (also known as antifreeze) level in your 2023 GMC Sierra 3500 HD is pretty easy. In order to get an accurate reading, your 6.6 liter engine should be cool to the touch when you check it. Engine coolant / antifreeze circulates through your engine to keep it cool in the summer but won't freeze in the winter. The video above shows you where the coolant reservoir in your Sierra 3500 HD is located and how to check the coolant / antifreeze level. If you need to add anti-freeze, be sure to check your owners manual to determine the correct type of coolant to add - in GMCs, it usually located in a section titled Fluid Capacities towards the end of your manual. See our video on how to add engine coolant for tips on adding coolant to your Sierra 3500 HD.

Always wear safety goggles when working on your Sierra 3500 HD. Taking off the coolant reservoir cap on a warm engine could cause the cap to up explosively and fluid to spray out of the reservoir. If you notice an oily surface in your coolant, immediately have your mechanic inspect your Sierra 3500 HD for head gasket leakage.