I've got a 2006 Hummer H3, bought new in 06 by my dad, and sold to me in 2017. Recently made a cross country drive with it, and noticed the engine has started overheating. I can smell coolant on the passenger side of the hood, and when I opened it up I saw where I thought the coolant like might be coming from. Anyone know what might be the cause?

The corner where i think the leak is coming from.

Evidence of potential leak

 

SEARCH H3 Radiator leak here. It's very common for the metal and plastic to separate on radiators.
Time for a new one.

 

X2 what he said. Common place. Might be more common with the I5s due to their funky vibrations?

It is not a difficult DIY project. There are threads here and vids out their on the web to help.

Welcome to HF.