Motorad 668-212 Engine Coolant Thermostat Housing Assembly

Integrated Housing Thermostat for Mercedes-Benz Cooling Systems

Motorad 668-212 is an integrated housing thermostat assembly built for OE-style cooling system service. It combines the thermostat, housing, sensor, and gasket in one replacement unit for select Mercedes-Benz models, including C300, E350, ML350, and GLK350 applications.

With a 212°F opening temperature, this thermostat is specified for vehicles that require precise coolant flow control and stable operating temperature. The Motorad Integrated Housing Thermostat line is engineered for direct-fit replacement where the thermostat and housing are serviced together.

Key Features

• Part number: 668-212
• Integrated housing thermostat assembly
• 212°F opening temperature / start-to-open temperature
• Bleeder hole and jiggle pin included
• Gasket/seal included
• 2 bolt holes and 1 outlet port
• Outlet diameter: 2.02 in
• Constructed from aluminum, stainless steel, and copper
• Silver finish
• OE supplier manufacturing with OEM specifications and processes

Product Details

Motorad 668-212 is manufactured with OEM-quality materials and built to meet the demands of modern engine cooling systems. The copper case and wax compound are used to promote quick response to coolant temperature changes, while the offset design, air relief valve, and OEM-style sealing features support proper system operation where applicable. This part cross-references Bosch 66812 for the same application.

Compatible With Mercedes-Benz C300, E350, ML350, GLK350, C350, and related applications listed below, this thermostat housing assembly is a direct replacement choice for service work on Mercedes-Benz cooling systems. It is also a relevant replacement for Mercedes-Benz S400 and R350 applications that require the same 212°F specification.

Common Cooling System Issues It May Address

• Engine running too cool or too hot due to thermostat wear
• Coolant temperature fluctuation during normal driving
• Leaking thermostat housing or degraded gasket seal
• Slow thermostat response from aging wax element
• Service needs on integrated thermostat and housing assemblies

Installation Notes

Verify the OE temperature specification before installation and confirm the housing style, outlet diameter, and bolt-hole layout match the original part. This assembly includes the thermostat, housing, sensor, and gasket where applicable, but does not include bolts or mounting hardware. Clean the mating surfaces thoroughly and inspect the cooling system for contamination, trapped air, or damaged seals before refilling.

Fits 2006-2007 Mercedes-Benz C280, N/A; Fits 2006-2009 Mercedes-Benz C230, N/A; Fits 2006-2009 Mercedes-Benz CLK350, N/A; Fits 2006-2011 Mercedes-Benz C350, N/A; Fits 2006-2011 Mercedes-Benz E350, N/A; Fits 2006-2011 Mercedes-Benz ML350, N/A; Fits 2006-2012 Mercedes-Benz R350, N/A; Fits 2006-2008 Mercedes-Benz SLK280, N/A; Fits 2005-2011 Mercedes-Benz SLK350, N/A; Fits 2007-2009 Mercedes-Benz CLK280, N/A; Fits 2007-2011 Mercedes-Benz CLS350, N/A; Fits 2007-2008 Mercedes-Benz E280, N/A; Fits 2008-2009 Mercedes-Benz E300, N/A; Fits 2008-2012 Mercedes-Benz C300, N/A; Fits 2009 Mercedes-Benz C280, N/A; Fits 2009 Mercedes-Benz E280, N/A; Fits 2009 Mercedes-Benz GLK350, N/A; Fits 2009-2011 Mercedes-Benz SLK300, N/A; Fits 2010-2011 Mercedes-Benz C250, N/A; Fits 2010-2011 Mercedes-Benz ML450, N/A; Fits 2010-2012 Mercedes-Benz GLK300, N/A; Fits 2010-2012 Mercedes-Benz GLK350, N/A; Fits 2010-2013 Mercedes-Benz S400, N/A

Quality Assurance

Motorad manufactures this integrated housing thermostat as an OE-supplier product using OEM specifications and processes. The design and materials are selected to support consistent coolant control in Mercedes-Benz applications that require a 212°F thermostat setting.