is there a timing belt or chain on the uplander

I have a 2005 Chevy uplander and I need to know the same thing,does it has a chain of robber belt? Lately I hear a click under the hood,something coming from the robber belt( starter,a/Celtic..). Strangely when I put on the air conditioning a big amount of smoke start to come from under the hood and I am 100% sure something is leaking because oil is all over especially around the robber belt area. Should I change this belt too? Any hints regarding this problem? I never made I tune up,never inspected in almost 9 years and never touched anything under the hood. Please just direct me to do the best thing! Thanks