If you have found evidence of corrosion anywhere in your cooling system, such as debris in your radiator, corroded sensors inside your thermostat housing, or even a rotted thermostat housing, chances are the freeze plugs have begun to rust from inside of your engine as well. These are an often overlooked item that can lead to coolant leaks if left alone for too long. Freeze plug leaks will usually start as a coolant leak that comes and goes, then eventually turns into a steady leak if given enough time. These leaks will usually start as a pinhole leak from around the center of the plug instead of a leak around the edges. While it is best to replace freeze plugs as a complete set, the plugs can be replaced individually as needed. This genuine, original equipment (OEM) plug installs on both sides of the engine block and the rear of the driver's side cylinder head. Sold individually, 12 required for the engine block, 1 required for the cylinder head*.
The left (Driver's) cylinder head has a freeze plug located on the back of the head (closest to the firewall). The passenger side cylinder head does not have a matching plug.
1984, 1985, 1986, 1987, 1988, 1989