How do I find the engine size on a 1965 Chevrolet Impala SS?
Locate the small flat pad area on the front passenger side of the block just below the front passenger side of the head. You may need to clean that area to see the stamped ID numbers. Post all the letters and numbers you find on that pad and we can decode them for you.
The 2000-2005 Chevrolet Impala only came with a 3.4 and 3.8 V6 (6 cylinder) engines. Are you sure that you don't have a Malibu instead? at the emd of the upper rad hose you will find the thermostat housing. Take the 2 bolts out and remove it. When reinstalling it make sure the spring on the thermostat goes toward the engine.