Where is the engine coolant heater located on a 2002 silverado?

On a 2002 Silverado, the engine coolant heater (block heater) is located on the engine block itself, typically on the passenger side (right side) of the engine. It's usually a cylindrical or slightly conical shaped element that screws into a threaded port on the block.

However, it's not always present on all 2002 Silverados. Whether or not your truck has one depends on the original options it was equipped with and the climate where it was sold. Check your owner's manual (if you have it) or look closely at the engine block – you'll be looking for a cord coming from the engine block near the passenger side. The cord will plug into an electrical outlet.