15 mm
Assuming you want to drain the engine oil, the original drain plug would require a 15mm box end wrench to remove it.
the radiator drain plug is on the bottom right facing car from front. you may have to remove the sheild to get at it. my 2000 malibu uses a allen wrench to loosen the drain plug for the radiator. good-day !
Don't use a wrench, use a socket. It will be metric, so just try your metric sockets until you find the one that fits.
If it is an original style drain plug a 15mm wrench is what you want.
Remove the transmission pan and ou will see why this 'drain plug' feature is not required.
front splash shield has to come off! then you can see the drain on the right bottom of radiator looking at it from front of car. you can use a Allen wrench to loosen the drain plug.
Assuming you mean the engine oil drain plug, a 15mm wrench should do the job.
Drain the fuel from your 2000 Chevy Malibu fuel tank. Remove the fuel line. Remove the fuel filter retaining plate. Reverse the process to install the new fuel filter.
Drain the oil from your 1999 Chevy Malibu oil pan. Remove the oil pan retaining bolts. Remove the oil pump retaining bolts. Reverse the process to install your new oil pump.
Drain the oil from your 2003 Chevy Malibu oil pan. Remove the oil pan retaining bolts. Remove the oil pan gasket. Put a new gasket on the new oil pan and reverse the process.
The Chevrolet Malibu radiator drain plug can be found on the right side of the radiator. The drain plug will be at the bottom of the radiator.
The drain plug would be at the lowest point under the engine. It will take a 15mm wrench to remove it counterclockwise.