Description
This thermostat fits the Honda Acty Truck HA3, HA4 (1990-1999). It regulates coolant flow so the engine warms up quickly and holds temperature.
In Stock - ships from our California (USA) warehouse
Fast, reliable delivery - no overseas backorder wait.
Vehicle Fitment & Compatibility
Confirm your chassis code against the table below before ordering.
100% Fitment Guarantee
Not sure about fit? Add your chassis/VIN number at checkout and we confirm it before we ship. If a part does not fit your Acty, we exchange it or refund you in full.
Signs you need this thermostat
- Slow warm-up or a gauge that never reaches normal
- Overheating or temperature that swings
- A stuck-open or stuck-closed thermostat
- Poor heater output
Features & Function
- Regulates coolant flow and temperature
- Correct opening temperature for the E07A
- Restores steady running temperature
Installation Specifications
- Difficulty: Moderate.
- Estimated time: about 45 minutes to 1 hour.
- Required tools: A socket set, a coolant catch pan, and a scraper.
Oiwa Garage Tech Note
"Fit it with the correct end and jiggle valve facing as the original, clean the housing faces, and bleed the cooling system after so no air pocket cooks the engine."
Frequently Asked Questions
Which way does the thermostat go in?
Match the original orientation, with the spring side toward the engine. Clean the housing faces before fitting.
Do I need to bleed the cooling system?
Yes. Refill and bleed out the air so the new thermostat reads the true coolant temperature.
How do I test my thermostat?
Watch the gauge from a cold start; if it never reaches normal, or overshoots and swings, the thermostat is stuck. Off the truck you can drop it in hot water and watch whether it opens.
Fitment verified by the Kei truck specialists at Oiwa Garage ยท Listing updated June 2026.