There is a plastic drain plug with protruding tabs on the bottom left side of radiator(driver's side)... NOT on the back of the radiator as others have INCORRECTLY stated. You will need a 3/4 socket. Go up from the bottom of the car, there is an access hole through the lower splash shield.
Driver side
where is the drain plug for the radiator on a 1992 buick regal custom
Look at the bottom or rear of the radiator
driver'side lower radiator
Drain plug is located right on top the right side of the engine where the radiator hose connects to the manifold. That is also where the thermostat is located.
There isn't one. You will have to loosen the lower radiator hose to drain the radiator.
Is there a drain plug on a 2005 Buick century
Try either the bottom or rear of the radiator--perhaps hidden by lower hose
If there is no petcock on the bottom of the radiator then you must remove the lower radiator hose to drain it.
on the oil pan
You can find the 1991 Buick Skylark radiator drain plug on the bottom of the radiator. The radiator drain plug will be in the center of the radiator bottom.
It's on the Driver's side near where the headlight is.
If the radiator is original, LEAVE DRAIN PETCOCK ALONE !! You may NOT be be able to close it completely due to rust. Disconnect lower radiator hose instead.