Replacing an engine thermostat typically costs $150 to $500 at a shop. The thermostat itself is cheap at $15 to $80, so labor and coolant make up most of the bill. Cost depends on how buried the housing is and whether it comes as an integrated housing assembly.
$150-$500
typical shop cost
$15-$80
part only (DIY)
0.5-2 hrs
typical labor time
📊 Quick Comparison
Vehicle type
Parts
Labor
Total
Economy sedan
$40
$110
$150
Midsize/SUV
$80
$180
$260
Full-size truck
$100
$200
$300
European/luxury (housing)
$150
$250
$400
What it costs
Most thermostat jobs run $150 to $500. The part is inexpensive, but some engines bury the thermostat under the intake or behind other components, and many modern cars use a plastic thermostat housing that must be replaced as a unit.
Refilling and bleeding the cooling system is part of the job, and integrated housing assemblies cost more than a bare thermostat.
Parts vs labor
The thermostat and coolant are cheap; labor is the variable. An accessible thermostat is under an hour, while a buried one or a housing assembly takes longer.
Thermostat: $15 to $80
Integrated housing assembly: $40 to $150
Coolant: $20 to $60
Labor: $80 to $300
Signs you need it
Engine overheating, a temperature gauge that stays low or swings erratically, poor heater output, a check-engine light for coolant temperature, or coolant leaking from the housing all point to a bad thermostat.
Overheating or temperature swings
Gauge stuck low, engine never warms up
Weak cabin heat
Coolant leak at the thermostat housing
DIY vs shop
A thermostat is a classic budget DIY job when accessible. Drain some coolant, remove the housing, swap the thermostat and gasket, refill, and bleed. The main cautions are getting the thermostat orientation right and purging air from the system.
How to save
Replace the thermostat and gasket together and use quality coolant. If the housing is plastic and brittle, replace the whole assembly to avoid a repeat leak. Bleed the system fully to prevent overheating from trapped air.
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The 50 most common check engine codes with likely cause and DIY fix cost. Sent once.
❓ FAQ
Can I drive with a bad thermostat?
If it is stuck open the engine runs cold and inefficient. If stuck closed it overheats fast, which can warp the head, so do not drive on a closed thermostat.
How do I know if the thermostat is stuck?
Stuck closed causes quick overheating; stuck open means the engine never reaches temperature and the heater is weak. A temperature reading confirms it.
Should I replace the housing too?
If it is cracked, warped, or a brittle plastic unit, yes. Many modern cars integrate the thermostat into the housing, so you replace it as one part.
Why does my engine take so long to warm up?
A thermostat stuck open lets coolant flow constantly, so the engine struggles to reach operating temperature. Replacing it restores normal warmup.
Do I need to bleed the cooling system after?
Yes. Trapped air causes overheating and poor heat. Follow the bleed procedure for your vehicle after refilling the coolant.
How long does a thermostat last?
Often 100,000-plus miles, but old coolant and corrosion can cause it to stick earlier. It is a common failure on high-mileage engines.