The thermostat regulates engine temperature. When it sticks open, the engine never warms up, the heater is weak, and the computer runs rich. When it sticks closed, the engine overheats fast. Both are common failures and both are a quick driveway repair on most vehicles.
Signs you need thermostat replacement
- Temperature gauge never reaches normal
- Weak heat in winter
- Check engine code P0128
- Sudden overheating with a full radiator
What we do on site
- Confirm with live coolant temperature data
- Drain coolant partially and remove the thermostat housing
- Install a new thermostat and gasket or housing assembly
- Refill and bleed, verify proper warm-up
Doing this in a driveway
Easy mobile job on the vast majority of engines.
Parts we use
Thermostat and gasket, or complete housing assembly on vehicles where it's integrated; coolant.
Pricing: Low on most vehicles; some housings that integrate sensors and the thermostat cost more. Every job is quoted in writing before we start, and there's no upsell — how our pricing works.
FAQ
Thermostat Replacement: common questions
What is code P0128?
'Coolant temperature below thermostat regulating temperature' — the engine isn't warming up fast enough. Nine times out of ten it's a thermostat stuck open.
Why is my heater blowing cold?
Low coolant, a stuck-open thermostat, a clogged heater core, or a bad blend door actuator. We check them in that order.