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, avoid RTV on the thermostat O‑ring unless the manufacturer specifically allows it.
• Tighten the housing bolts evenly to the factory spec from the service manual—don’t guess.
• Refill with Honda Type 2 (blue) premix or an equivalent HOAT that meets Honda specs, bleed air with the heater on HOT, and top up once the fans have cycled.

A housing doesn’t have a set replacement interval—it’s changed on condition. Many owners replace it only when it leaks or while renewing the thermostat and lower radiator hose for peace of mind. Consistent coolant changes (time or kilometres) slow corrosion and help the housing, thermostat, and pump live a longer, happier life.

Does the 2003 CR‑V definitely have a thermostat housing?

Yes. Honda’s CR‑V service manual for 2002–2004 covers thermostat and housing removal/installation, and the Honda parts catalogue lists a thermostat cover/housing for the K24A1. Aftermarket catalogues also supply direct‑fit housings for this exact model year.

Where is the thermostat housing located on a 2003 CR‑V?

It’s low on the engine, at the point where the lower radiator hose joins the block. Access is typically easier from underneath once the splash shield is off. Expect some coolant loss when the housing is opened.

Should the housing be replaced when changing the thermostat?

Not always. If the housing’s flange is flat, the hose neck is clean, and there are no cracks or corrosion grooves, it can be reused with a new thermostat O‑ring. If there’s pitting, warpage, or leakage history, replacing the housing along with the thermostat and hose clamps is smart preventative maintenance.