Review on ACDelco GM Original Equipment 15-11006: Engine Coolant Thermostat & Housing Assembly – Efficient Performance and Durability by King Reeves

This part is obviously a perfect replacement for the original thermostat. Product photos are not very accurate but mine arrived as an aluminum casting just like the original. I installed it on my 2003 Trailblazer EXT 4.2L in about an hour. Installation was easy and required few tools. Tools: 3/8" breaker 3/8" ratchet 3/8" extension (6") 3/8" swivel 8mm socket 10mm socket 15mm socket Channel lock pliers 1 - Disconnect the battery (8mm bolt) . 2 - Remove the poly V-belt from the alternator pulley (the tensioner uses a broken 3/8" rod) 2 - Remove the AC line bracket (10mm bolt) from the LF engine lift bracket. (3 bolts 15mm) 4 - Completely loosen (15mm) the lower alternator mounting bolt. You cannot remove the screw yet.5 - Remove the top screws of the generator (2x 15mm)6 - Tilt the generator forward to access the cable connectors.7 - Disconnect the plastic connector (no tools required)8 - Pull Close the protective cover and remove the top battery cables (10mm) 9 - Turn the alternator so that the pulley is facing up and the brackets are facing left and right. This allows it to fit between the engine and the radiator fan when removed. You now have good visibility and access to the thermostat/water inlet. The hose clamp can be squeezed with pliers and the water inlet is attached to the unit with two 10mm screws. Not much coolant comes out when the hose is removed, but A LOT comes out when the neck is removed. After replacement, the parts can be installed in the reverse order of removal. Remember to put the alternator bottom bolt into the alternator before installing it.