Thermostat Housing Gasket 04-06 Chevy LS

The Thermostat Housing Gasket 04-06 Chevy LS is a critical sealing component engineered for LS-based engines in fourth and fifth-generation Chevrolet vehicles. This gasket sits between the thermostat housing and the engine block, preventing coolant leaks that can lead to overheating, air pockets in the cooling system, and catastrophic engine damage. Whether you're running a stock setup or a modified LS swap, a degraded or failed thermostat housing gasket creates symptoms that range from slow coolant seepage to sudden overheating during highway driving—making replacement a priority maintenance item.

Manufactured by MAHLE ORIGINAL/CLEVITE under part number C31823, this gasket is engineered from premium elastomer and composite materials designed to withstand the thermal cycling of modern LS engines operating in the 180–220°F coolant temperature range. The gasket's ultra-thin profile (0.3 inches) allows for precise fitment without requiring shim stacking, while its engineered surface ensures a watertight seal against both aluminum and cast-iron thermostat housings. MAHLE's manufacturing tolerances guarantee consistent geometry across production batches, eliminating the leakage issues common with aftermarket gaskets that lack factory precision.

This gasket is essential for LS engine builders, performance tuners, and daily-driver owners maintaining 2004–2006 Chevrolet Silverado, Tahoe, Suburban, and Corvette models equipped with LS2 or LS3 variants. Installation requires draining the radiator, unbolting the thermostat housing, and cleaning both sealing surfaces—a 20-minute job for experienced mechanics. Pair this genuine MAHLE gasket with fresh coolant and a quality thermostat to restore cooling system integrity and prevent recurring leaks that compromise engine reliability during both street and track use.