Where are the freeze plugs on 94 chevy lumina?

The freeze (or also called frost or expansion plugs) plugs are located on each side of the engine - there should be one for each cylinder. As for the location of a freeze plug, there should be none located behind the serpentine belt. If your coolant leak is indeed coming from behind the serpentine belt, we recommend inspecting other components of the cooling system, such as the intake manifold, water pump, or timing cover, as coolant flows through those areas as well. JB Weld is not a recommended repair for a freeze plug. Typically, most qualified technicians replace the original freeze plug (which is usually made from steel or galvanized steel) with a brass plug, which helps prevent future corrosion. Replacing the freeze plug by itself is usually not difficult, but rather the components or parts that need to be removed to gain access to the plug. As we live in Minnesota, we will occasionally replace the freeze plug with an engine block heater.