my 2003 Impala 3.4 is over heating!?

I bought my 2003 Chevy Impala three years ago and haven't had much trouble...until two weeks ago when it ran hot. So much that the warning light came on. It has 149,000 miles so realize it would need some parts. My brother recommended checking the fans, so the first thing I did after realizing only on of the two was working was to replace the fan assembly with a brand new one. It worked fine for two days then ran hot right before I reached my job. and when I reached my job (20 miles away) It dumped all the coolant on the ground. I couldn't tell from where exactly. Now I'm putting a brand new radiator...but it heated up 3/4 . Any advice before I spend more money. Does te 3.4 v6 also have the intake gasket problem.?