Where is the thermostat in your 1999 Chevy Malibu 2.4L?

The thermostat in a 1999 Chevy Malibu 2.4L engine is located on the engine block, typically at the back (or rear) of the engine, near the cylinder head. It's not easily accessible without some mechanical aptitude and tools. You'll need to consult a repair manual specific to your vehicle's year and engine to get a precise location and detailed instructions for replacement, as there can be slight variations depending on the exact model and build. Looking at online diagrams specific to your 1999 Malibu 2.4L engine would be very beneficial.