Just beneath the lower radiator hose is the drain.
It is on the very bottom of the engine on the oil pan.
Drain the coolant either by undoing the bottom hose or using the drain cock. Then fill with water. Run the engine until it is at normal operating temp then drain again. Do this until the coolant is clean. Then refill the radiator either by the radiator cap or overflow tnk. Run until at operating temp then recheck the level and add as needed. That's it. Good luck.
Drain the radiator in a container. Remove the engine end of the top radiator hose. The housing has 2 bolts that you remove. Remove the thermostat and clean the surfaces and reinstall the thermostat. Reinstall the hose and add coolant.
There is a plastic drain valve on one of the bottom corner's of the radiator (facing engine) open valve and properly catch & dispose of coolant that comes out. You may need to use pliers to loosen drain valve. Tighten by hand.
To drain the radiator of a 1995 Chevrolet Astro Van, first ensure the engine is cool to avoid burns. Locate the radiator drain plug at the bottom of the radiator and place a container underneath to catch the coolant. Open the drain plug, allowing the coolant to flow out completely. Once drained, close the plug and refill the radiator with the appropriate coolant mixture.
You drain coolant from the radiator. but according to the book ther are two plugs on the engine block that need to drain the coolant from.
The radiator drain plug on a 2002 Chevy Impala is typically located at the bottom of the radiator, on the driver's side. It may be a small plastic or metal valve that you can turn to release coolant. Be sure to have a container ready to catch the coolant when you open the drain plug. Always ensure the engine is cool before attempting to drain the radiator to avoid burns.
It's a small drain cock on the bottom of the radiator.
It is beneath the lower radiator hose.
Answering "Where is engine coolant drain plug for a 1.8 Nissan sentra engine?"
The 2005 Chevrolet Impala air conditioning evaporator drain is located on the bottom of the air conditioner compressor. The evaporator drain should have a tube attached to it.
Drain the radiator into a container. Remove the top radiator hose at the engine. Remove the 2 bolts holding the thermostat housing and remove the thermostat. Clean both surfaces and install the new thermostat. Reinstall the upper radiator hose and the coolant.