Fix Coolant Leaks: 2003 GMC Sierra Denali 6.0L V8

GMC Sierra Denali Model Years - 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007

How to fix a radiator and coolant leak with stop leak

ASE-validated: reviewed by ASE-certified technician validated

Author

Hans Angermeier is an ASE certified Maintenance and Light Repair Technician and has produced over 100,000 videos showing drivers how to fix things on their cars. He has broad expertise on basic repair procedures covering the majority of cars on the road. Over the past 10 years, Hans has been focused on building CarCareKiosk, which is visited by millions of drivers each month.

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Video Description

Follow the steps in this video to see how to fix minor coolant (antifreeze) leaks in your 2003 GMC Sierra Denali. Leaking coolant / antifreeze is one of the more common types of leaking fluid from Sierra Denali engines. Engine coolant (which is also called antifreeze or anti-freeze) moves through the inside of your Sierra Denali engine and keeps it from overheating. Coolant / antifreeze can leak from the reservoir, radiator or any hose, in 2003 Sierra Denali with the 6.0 liter engine. However, a coolant leak (aka an antifreeze leak) is most likely to occur where the hoses connect to the engine or radiator. Otherwise, your Sierra Denali may have a radiator leak. This video shows you where the coolant reservoir, hoses and connections on your 2003 Sierra Denali Base are located and the steps needed to fix minor leaks.

A few things to note about coolant is that it is sweet tasting and highly toxic, so it can end up in the dog's stomach pretty quickly. If you ignore a small coolant leak long enough, you will run out of coolant, which leads to an overheated engine and other serious, but highly avoidable, problems. An anti-freeze leak can cause the temp sensor to record high engine temperatures in a 2003 GMC Sierra Denali. Always protect yourself with safety glasses and gloves when working with the coolant on your Sierra Denali.

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