2006 yukon xl 1500 losing coolant

[skikat]

My 2006 Yukon uses coolant excessively. I never see any leaks and I have to add fluid to it reguarly. I can't figure out where all the coolant is going

 

[Marky Dissod]

My 2006 Yukon uses coolant excessively. I never see any leaks and I have to add fluid to it regularly. I can't figure out where all the coolant is going

After 20 years, if you've not yet replaced the coolant reservoir cap, feel free to fire the parts derringer at it.
Next is to actually check for leaks. Is your front carpet wet? What about the right rear wheel area? Also check the firewall insulation, the T- & Y- are getting old too.

 

[Fless]

How many miles? Any engine work done on it recently or in the past year or two?

Worst case it could have a cracked head or blown head gasket and the coolant is getting burned in a cylinder or two, or getting mixed with the oil; does the oil look milky? I would recommend having an experienced shop look at it to see if they can determine the cause of the coolant loss, before it could cause a catastrophic engine failure.