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

Thermostat works as intended and replaces a stuck OEM thermostat. The thermostat is one of the trickiest things on a GM 4.2 engine, no simple method will work no matter how hard You Tube mechanics try to tell you. It's best to start with knowledge of the difficulty and bring plenty of patience, a long-sleeved shirt and the right tools. A short wrench is required for the bottom alternator bolt. I could write a lot more, but I'll stop here. The complexity of the installation is due to the design of the 4.2 and not the actual product sold.