Parts for your 2003 Honda Cr-v-Thermostat housing

2003 Honda CR‑V Thermostat Housing: purpose, care, and when to replace

Technical sources confirm the 2003 Honda CR‑V (K24A1 engine) is fitted with a thermostat housing. Honda’s 2002–2004 CR‑V Service Manual (Cooling System – Thermostat Replacement) details the housing and its removal/refit, and the Honda Electronic Parts Catalogue lists related parts such as the Cover, Thermostat (commonly referenced as 19320‑PLC‑000) and the Thermostat (often 19301‑PLC‑315). Major aftermarket catalogues also list direct‑fit thermostat housings/inlet covers for this model. So yes—this vehicle does use a thermostat housing.

On the 2003 CR‑V, the thermostat housing sits low on the engine where the lower radiator hose meets the block. Its job is to securely locate the wax‑pellet thermostat, seal the coolant passage, and direct cooled fluid from the radiator to the water pump. The housing also provides the hose connection and, on some variants, a mounting point for sensors or bleed features. Because it locks in the thermostat’s position and seals the passage with an O‑ring, it’s central to accurate warm‑up, stable operating temperature, heater performance, and fan control logic.

During routine servicing, the housing deserves a quick look. Owners should check for: white or pink crust at the flange or hose neck (dried coolant), dampness or staining under the housing, hairline cracks, and corrosion that can nick the O‑ring. Over‑tightening or old coolant can warp or pit the mating surface, so even alloy housings aren’t immune.

• Replace the housing if there are cracks, a distorted flange, deep corrosion, or a persistent leak that a new O‑ring won’t cure.
• When fitting a new thermostat, always use a fresh O‑ring and orient the jiggle pin at 12 o’clock as per Honda guidance.
• Clean the mating faces carefully