The 2001 Service Manual makes no mention of any block drain plugs in the "Draining and Filling Colling System" instructions. It only mentions opening the radiator drain cock after opening the surge tank cap to allow air into the system as the coolant is drained.
There are some warnings:
Use only DEX-COOL (50% mix with clean drinkable water)
Don't use silicated coolant or seal tabs
Properly dispose of the used coolant - not down the drain
Don't use a chemical flush
Follow the proper filling procedures to avoid air pockets and possible engine damage.
1. Park the vehicle on a level surface.
2. Remove the surge tank cap:
2.1. Slowly turn the cap counterclockwise 1/4 to 1/2 turn and stop. Do not press down.
2.2. Allow any residual pressure , indicated by a hissing sound, to be relieved.
2.3. After all pressure is released, remove cap.
3. Open the radiator drain cock. (It looks like a white plastic plug below the lower radiator hose. You can see it if your car is jacked up and you are under it). Use a ¼ inch ratchet extension to turn it. Do not turn more than ¼ of a turn or you will break the plug. Use a flat blade screwdriver if necessary to gently pull the plug.
4. Allow the system to drain completely.
5. Inspect the engine coolant:
-Discolored – Follow the flush procedure below
-Normal in appearance –continue the next step
6. Close the radiator drain cock.
7. Fill the system through the surge tank to the base of the neck.
8. Start the engine.
9. Idle engine for 1 minute.
10. Install surge tank cap.
11. Cycle the RPM, from idle to 3000 in 30 second intervals until engine coolant temperature reaches 210 F.
12. Shut off the engine.
13. Refer to step 2 above to remove the surge tank cap.
14. Start the engine.
15. Idle engine for 1 minute. Fill the surge tank to ½ inch above the COLD FULL mark.
16. Install surge tank cap.
17. Cycle the RPM, from idle to 3000 in 30 second intervals until engine coolant temperature reaches 210 F.
18. Shut off the engine.
19. Refer to step 2 above to remove the surge tank cap.
20. Top off coolant as necessary, ½ inch above COLD FULL mark.
20. Rinse away any excess coolant from the engine and the compartment.
21. Inspect the concentration of the coolant.
22. Install surge tank cap.
Flush Procedure.
1. Block the drive wheels.
2. Place the transmission in Park or Neutral
3. Engage the parking brake.
4. Run the engine until the thermostat opens.
5. Stop the engine
6. Follow the drain and fill procedure using clean drinkable water until the fluid is nearly colorless. Refer to Draining and Filling Cooling System.
7. Fill the cooling system. Refer to Draining and filling cooling system.
