I noticed the leak a couple months ago, green coolant dripping from the front driver's side of the car. I was hoping it was the upper radiator hose that needed to be replaced, but after replacing it, the leak was still there. The leak would stop after the car cooled down, but over time got worse.

Since it wasn't the upper radiator hose, it had to be the radiator or the drain plug -- those are the only two other coolant related parts that could leak in that spot. The drain plug was fine, so it had to be the radiator. Ordered a new radiator off partsgeek.com for $66, came out to around $77 with shipping. Took out the old one and installed the new one myself, took me about 6 hours I think, spread it out over a couple days. I'm not a mechanic, suspect a mechanic could do it faster since I spend a good deal of time finding the bottom fastener holding the fan assembly in place, fighting with pliers to undo the bottom radiator hose, and trying to undo clips that guide the wiring harnesses to the fan assembly. Eventually got the old one out and put the new one in. Been driving it a few days now, temperature holds steady around 180F and the coolant is now staying in the radiator, where it should be.

Fun weekend project, made me feel pretty manly and handy.

Update from Feb 25, 2015:

First, there's that annoying clunking noise coming from the steering column(a known GM/Impala issue/TSB). Then my traction control went squirrelly... giving me feedback on the brake pedal when ever I make some sort of turn or turning while braking. Next, the tranny shifts weird. After that happened, the exhaust manifold developed a leak. That repair cost me $1,000.

Now, my latest episode is that my engine cuts off without warning, randomly, and most inconveniently(meaning while on the freeway going uphill). I still haven't found a fix. No wonder GM sales took a dive the last 5 years. The sad thing is that I used to love GM cars, Chevy's especially. I think I'll be buying a Hyundai. At least they have been making reliable and affordable cars that have a lot of features and they stand behind their cars.

my a/c always worked ok.. now it doesnt work.. service put in refrigerant twice with dye... cant find leak.. they say the leak is probably in the evaporator.. the evaporator is located on the inside of firewall.. to fix the part ($140) which doesnt seem so bad requires the removal of the entire dashboard, the steering column and something called the cross brace.. anyway the quote for the fix is 1300 bucks... hardly worth the trip.. the complaint is why the heck do they design something that can fail and requires all of this crap to fix.