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

OEM part, not OEM dealer price. Fixed Envoy slow warm up with 4.2 L6. Painful replacement - search the web for full instructions - there are many ways to replace this part. This is why they built the thermostat into the throat as there would be no way to hold the thermostat and then place the body on top of it. It fits perfectly, it was an OEM part. Fixed slow heating issue, a common problem with these engines. Use a scanner and monitor your temperature. I also recommend replacing the temperature sensor block, which is also difficult to replace on this engine. After replacing this thermostat and neck assembly, you can claim victory and feel like you can rock the world! On the 06 it was located at the bottom of the engine on the driver's side behind the alternator, which usually had to be removed for installation. I was able to go through the left front wheel, but I have a large tool box and a hoist which made the job bearable. Do yourself a favor - contact an OEM for this job, you'll hate life if you have to do it twice!