MITZONE Coolant Thermostat Housing Assembly for 3.6L Buick Cadillac Chevy GMC (2017-2023) — Complete Kit with Thermostat & Gasket

MITZONE Coolant Thermostat Housing Assembly is a complete replacement unit (housing, thermostat, gasket) engineered to fit 3.6L Buick, Cadillac, Chevy and GMC models from 2017–2023 for reliable cooling system performance.

If your vehicle’s thermostat housing is cracked, leaking, or the thermostat is sticking, swapping in a full assembly restores coolant routing and temperature control without hunting down separate parts. This MITZONE kit replaces OE numbers 12673659 and 12678779, and is built to meet OEM-style tolerances for a direct-fit installation on compatible 3.6L engines. The assembly is intended as a like-for-like service part for Club models including LaCrosse, Regal Sportback, XT5, XT6, Blazer and Acadia across the listed years.

Will this assembly fit my Buick, Cadillac, Chevy or GMC with a 3.6L engine?

Check vehicle year, model and engine displacement before ordering. MITZONE designed this assembly specifically for the listed model-year runs and 3.6L V6 engines; it replaces the factory housings with the same mounting points and coolant passages.

• Compatible models: 2017–2019 LaCrosse; 2018–2020 Regal Sportback
• Cross-compatibility: 2017–2023 XT5, 2020–2023 XT6, 2019–2023 Blazer, 2017–2023 Acadia
• OE replacement numbers: 12673659, 12678779 for reference

How difficult is installation and what comes in the box?

Installation is designed to be straightforward for technicians or experienced DIYers: the unit mounts where the original housing sat and uses the same bolt pattern. MITZONE ships a pre-assembled kit that reduces parts hunting and helps minimize downtime.

• Included parts: thermostat housing, thermostat, and gasket — ready to install
• Installation notes: follow OEM torque specs, replace coolant and bleed system per factory procedure
• No extra sensors are included unless originally fitted on the vehicle—verify sensor locations before removal

What materials and quality controls were used to make this thermostat housing?

MITZONE manufactures this assembly to meet OEM-style performance and dimensional standards, using durable materials that resist heat and coolant exposure. The thermostat element and sealing gasket are matched to the housing to reduce leak risk and ensure consistent operation.

• Materials chosen for thermal stability and corrosion resistance
• Precision-molded housing to maintain factory fit and coolant flow paths
• Complete kit minimizes fitment and compatibility issues

How long can I expect the replacement to last and when should I replace it again?

Longevity depends on driving conditions and coolant maintenance; a properly installed MITZONE assembly should perform comparably to an OEM unit. Regular coolant changes and system inspections will help the thermostat and housing last for many years and miles.

• Inspect for leaks after initial installation and during routine service intervals
• Replace coolant per manufacturer schedule to reduce corrosion and deposits
• If you encounter persistent overheating or coolant loss, re-evaluate hoses, water pump and radiator cap

Who this product is for: this MITZONE thermostat housing assembly is aimed at owners and technicians working on 3.6L-equipped Buick, Cadillac, Chevrolet and GMC vehicles from the listed years who need a complete, direct-fit replacement. It’s a practical choice for scheduled maintenance, repair after a leak or crack in the original housing, or when updating the thermostat during broader cooling-system work. If you want a single-kit solution that replaces the housing, thermostat and gasket with parts matched for fit, this assembly streamlines repair and reduces the chance of missing pieces during installation.