Parts for your 2006 Honda Fit-Thermostat housing

2006 Honda Fit thermostat housing – purpose, fitment and replacement tips

Technical documentation confirms the 2006 Honda Fit (Jazz GD, L13A/L15A engines) uses a dedicated thermostat housing. The Honda workshop manual for GD-series models and the Honda Electronic Parts Catalogue list a “thermostat case/water outlet” that holds the thermostat and seals to the engine block. Typical OEM references include items such as Case, Thermostat (e.g., 19320-PWA-300) and Cover, Thermostat (e.g., 19315-PWA-000), with variants by market and engine code. So, yes—this part is fitted and relevant on the 2006 Honda Fit.

On this little Honda, the thermostat housing sits where the lower radiator hose meets the engine, managing coolant flow as the engine warms up. It anchors the thermostat, routes coolant to the radiator, and provides a leak-tight seal with an O-ring. Some versions also carry the coolant temperature sensor or hose junctions. When it’s in good nick, the Fit warms quickly, holds steady temperature on the motorway, and keeps the heater toasty in winter.

Like any plastic or alloy cooling part, the housing can age: plastic can go brittle and warp, alloy can corrode at the sealing face. That’s when dribbles, crusty deposits, or that tell-tale sweet coolant smell show up. If the housing is distorted, even a fresh thermostat and O-ring won’t seal for long.

• Common signs it needs attention:
  • Coolant weeping around the housing or hose neck
  • Temperature gauge hunting, slow cabin heat, or overheating at idle
  • Pink/white staining and residue under the housing area

Servicing tips for owners and workshops:

• Inspect the housing at each coolant change. If it’s crazed, pitted, or out-of-round, replace it.
• Whenever the thermostat comes out, fit a new O-ring and clean the mating surfaces carefully—no gouges.
• A light wipe of clean coolant on the O-ring helps it seat, avoid RTV unless the Honda manual specifically calls for it.
• Refill with Honda Type 2 (blue) coolant or an equivalent silicate-free premix. Bleed air by running the engine with the heater on until the fans cycle, then top up the radiator and reservoir to the marks.
• Tighten housing fasteners evenly to the factory torque spec, don’t overdo it on plastic flanges.

There’s no hard-kilometre replacement interval for the housing itself, but pairing a new housing with a thermostat and hoses every 5–10 years (or when any leak shows up) is an easy reliability win for this model.

Popular questions

Where is the thermostat housing on a 2006 Honda Fit?
The housing is on the transmission side of the engine block, low down, where the lower radiator hose connects. It’s tucked under the intake side, so a torch helps. Follow the big lower hose from the radiator—its end lands on the housing.

Do I need to replace the housing when changing the thermostat?
Not always. If the housing face is flat and crack-free, a new thermostat and O-ring usually do the trick. If there’s warping, crazing, or corrosion, swap the housing at the same time—it’s inexpensive insurance against repeat leaks.

What coolant should I use after replacing the housing?
Use Honda Type 2 premixed coolant (blue) or a high-quality, silicate-free equivalent. Expect roughly four litres for a drain-and-fill, but always check the owner’s manual and top up to the marks after bleeding air.