Vehicle burns anti freeze, replace anti freeze every 2-3 weeks on 1996 GMC Yukon

All mechanics in town have worked on it, keep insisting no problem yet I have to keep adding anti freeze. I spent loads of money on this vehicle one mechanic taking everything out and replacing it back and yet it still burns anti freeze. Should I trade this in, they say no!!!

Asked by for the 1996 GMC Yukon
It should not "burn" antifreeze! If the engine runs hot it will boil out the antifreeze resulting in loss other wise you are experiencing a leak. The way an automotive shop would locate the leak is by removing the radiator cap and attaching an adapter that screws on in place of the radiator cap. Something that looks like a bicycle pump with a pressure gauge attached to it is used to "pump up" pressure to simulate pressure generated when the cooling system is at operating temperature, the leak is then found sometimes it is obviously leaking from a coolant hose or cracked housing, failed gasket or water pump, sometimes the engines cooling system needs to be inspected from below or inspected using a mirror and flash light.
Cooling system loss could be due to a blown head gasket.The most accurate way to test for a blown head gasket on a gasoline engine is to test for the presence of carbon monoxide in the cooling system. Snap-On, Matco (part # CO 2000), and Napa sell a tool to check to carry out this test. Another link to a supplier of this tool is Carbon Monoxide is only present if there is a blown head gasket or cracked cylinder head. I think the napa part number 700-1006. . Signs of a blown head gasket are coolant loss (frequently have to top up the coolant level of the engine without seeing an obvious leak), experiencing over heating or rough engine running or the presence of white sweet smelling steam from the exhaust. A badly blown head gasket may allow engine coolant and oil to mix.
Yes it is very helpful and i thank you. The mechanics around here shy away from my "mystery car" and have tried most everything they could think of to find the problem. Like I say I have spent a lot of money on it and it is a good vehicle in spite of this problem. I just don't want it to die on me. It only has 68,000 miles on it and otherwise a good vehicle. THANKS AGAIN