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Help! draining coolant out of engine block


New member
Jan 21, 2020
El Paso, Texas
1989 corvette red coupe
Hello, I have a 1989 corvette and I am upgrading the radiator. I am trying to flush my coolant but only can get about 4 quarts of coolant from my radiator. My cooling capacity is 14 quarts so I have about 10 more quarts in the engine block. I have tried to run the engine to normal operating temperature then shutting down in hope that my water pump would pump the coolant out of the block but that did not work. I also have read that you need to remove the knock sensor to get the coolant out of the block. I removed the knock sensor located above the starter and no coolant came out.(My car is on Jack stand so the front of the car is elevated not sure if I need to take the car of off the jack stand to level the car). My question on a 89 is there more than one knock sensor and is their any other block drain plugs that I need to remove to drain the the coolant out of the block and if so where are they located at. Any input will be highly appreciated and thank you, Bill
Stick a stiff wire or Ice pick into the hole the sensor came out of and knock the sedement out! Should be a plug on the other side of the block about the same place if there is no knock sensor, Some years have 2 sensors, Some don't!

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