Where is the drain plug for the radiator on a 2003 Chevy Impala?

Answer 1

probably same as 2000 impalaIf it is the same as the 2000( should be) it is on the lower right "backside" of the radiator. You can't get to this or the lower hose without removing the plastic ground scraper shroud under the radiator. This has 5 bolts holding this on. Then reach around the back of the radiator and you will feel a wingnut. You can loosen the drain knob with pliers, but a small crescent wrench on bolt attached to wingnut will prevent any stripping. The knob will only need a turn or less to loosen,,,,then you can use your fingers to adjust flow. I'm writing this while doing it myself. I also gave it a lil flush with some clean water while valve was open. (while nut is on the back of radiator,,,water drains through the rubber gasket under the radiator.)

Good information above- change in drain location between 2000 and 2003.

Just changed coolant in my 2003 Impala. Drain is on drivers side. Has hex. - open with a 19MM socket. Flush by temporarily inserting garden hose tee between heater hose and engine connection using piece of heater hose. After flush and drain (including coolant recovery bottle) run engine short time to drain water from engine. Add 6 quarts full strength coolant to radiator and top with water to insure 50/50 mix.