Thermostat Housing and Water Necks

Thermostat housing, water neck, water outlet, coolant housing…they’re all names for the same thing. This component is where the upper radiator hose plugs...

Thermostat housing, water neck, water outlet, coolant housing…they’re all names for the same thing. This component is where the upper radiator hose plugs in, and it also contains your mechanical thermostat. Grab a stock replacement to replace a leaky or broken one, dress up your engine with a chrome or anodized finish, or use a 360° swiveling model for versatility on your custom cooling system.

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Our powerful search tools make it easy to find the right water neck from manufacturers like Meziere, Dorman, Mr. Gasket, Four Seasons, Trans-Dapt, ACDelco, and so many more.

Top Brands

Our powerful search tools make it easy to find the right water neck from manufacturers like Meziere, Dorman, Mr. Gasket, Four Seasons, Trans-Dapt, ACDelco, and so many more.

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Rein Automotive Coolant Hose Flange Kits for 2005-2009 A4, A4 QUATTRO - CHS0648

Thermostat Housings, Coolant Hose Flange Kit, Includes 3 Hoses, 1 Flange, 1 Gasket, 1 O-Ring, 1 Sensor, 1 Lock Pin, 1 Thermostat, Audi, 2.0L, Kit

Part Number: RIN-CHS0648

5.0 out of 5 stars ( 2 )

Estimated Ship Date: Today

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Estimated Ship Date: Today

Rein Automotive Coolant Hose Flange Kits for 2002-2006 A4, 2002-2005 A4 QUATTRO - CHS0646

Coolant Hose Flange Kit, Thermostat Included, Sensor Included, Plastic, Black, Audi, Kit

Part Number: RIN-CHS0646

Not Yet Reviewed

Estimated Ship Date: Feb 2, 2026 if ordered today

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Estimated Ship Date: Feb 2, 2026 if ordered today

Rein Automotive Coolant Hose Flange Kits CHS0777

Thermostat Housings, Coolant Hose Flange Kit, Includes 1 Flange, Hardware, Plastic, Black, Freightliner, Mercedes-Benz, Kit

Part Number: RIN-CHS0777

Not Yet Reviewed

Estimated Ship Date: Feb 2, 2026 if ordered today

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Estimated Ship Date: Feb 2, 2026 if ordered today

Offenhauser Thermostat Control Bodies 5308

Water Neck, Aluminum, Natural, Remote Mount, Each

Part Number: OFY-5308

5.0 out of 5 stars ( 2 )

Estimated Ship Date: Apr 21, 2026 if ordered today

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Estimated Ship Date: Apr 21, 2026 if ordered today

CVR Thermostat Housings TSH7ACL

Water Neck, Billet Aluminum, Clear Anodized, O-Ring, 90 Degree, 16 AN, Ford, Small Block, 351W, Each

Part Number: CVS-TSH7ACL

Not Yet Reviewed