If your car’s temperature gauge keeps fluctuating or you hear rumbling noises, the thermostat could be failing.
Replacing a bad car thermostat typically costs $170 to $800. However, delaying it can cause serious damage to your engine or radiator and lead to more expensive repairs. That’s why it’s important to address thermostat issues ASAP.
Not sure how to proceed?
Don’t worry.
We’ll break down car thermostat replacement cost, key pricing factors, the replacement process, and a few smart ways to save money on the repair.
This Article Contains:
- How Much Does a Car Thermostat Replacement Cost?
- Is It Worth Replacing a Car Thermostat?
- 8 Red Flags You Need a Car Thermostat Replacement
- What Is the Lifespan of a Car Thermostat?
- How to Diagnose a Malfunctioning Car Thermostat and Replace It
- How Long Does a Car Thermostat Replacement Take?
- How to Save Money While Replacing a Car Thermostat
How Much Does a Car Thermostat Replacement Cost?
Here’s a breakdown of the total cost of swapping out a car thermostat:
A. Range
The average cost of replacing a car thermostat is between $170 and $800.
This includes:
- Parts cost: $20 to $300
- Labor cost: $150 to $500
B. Factors Affecting Cost
The following factors can affect your final bill:
- Vehicle make and model: Luxury or high-performance vehicles often require specialized parts, which can increase replacement costs. Vehicles with harder-to-access thermostats may also require more labor time.
- Type of thermostat: Electronic and variable thermostats are more advanced and typically cost more to replace than simple mechanical ones.
- Location: The labor cost varies by location and the mechanic’s hourly rate.
- OEM vs. aftermarket parts: Original equipment manufacturer (OEM) thermostats usually cost more than aftermarket alternatives. That’s because OEM parts are made by the vehicle’s manufacturer and designed specifically to fit your car.
- Related repairs: In some cases, additional services such as a coolant flush or thermostat housing replacement may be needed, which can increase the overall cost. For example, a coolant flush will cost an extra $132 to $265.
It’s also best to replace the thermostat gasket during the repair to prevent coolant leaks. This will cost around $5 to $20.
Before deciding whether to spend the money, it’s important to understand why thermostat replacement matters.
Is It Worth Replacing a Car Thermostat?
Yes, it is.
Ignoring a bad thermostat can lead to serious problems such as engine overheating, poor fuel efficiency, and weak cabin heating. If the engine overheats for too long, it can cause major damage, such as a blown head gasket or warped cylinder head. These repairs can be far more expensive than replacing the thermostat.
A malfunctioning thermostat can also prevent coolant from circulating properly, leading to pressure buildup in the radiator. Over time, this can lead to leaks or even a blown radiator.
To decide whether replacement is necessary, you first need to recognize the warning signs of a failing thermostat.
8 Red Flags You Need a Car Thermostat Replacement
These signs may indicate that you have a faulty thermostat:
- An illuminated check engine light: A failing thermostat can trigger the check engine light and store OBD codes such as P0128.
- Overheating engine: If the engine temperature rises above the normal range (195°F to 220°F), the thermostat is likely stuck closed, preventing coolant from circulating.
- Fluctuating temperature gauge: Rapid changes in the temperature gauge can indicate a malfunctioning thermostat.
- Coolant leaks near the thermostat housing: Leaks around the housing may be caused by a worn gasket, corrosion in the area, or damage to the thermostat.
- Poor cabin heating: If the thermostat is stuck open, the engine may not reach its normal operating temperature, preventing the heater from producing warm air inside the cabin.
- High idling: The engine may idle higher than normal if it struggles to maintain the correct temperature.
- Poor fuel economy: When the engine runs below its optimal operating temperature, it may burn more fuel than usual, reducing fuel efficiency.
- Strange noises: Unusual sounds from the engine or cooling system, such as knocking or clicking noises, may occur if coolant flow is disrupted.
However, even without obvious symptoms, a thermostat may still need to be replaced once it reaches the end of its service life.
What Is the Lifespan of a Car Thermostat?
A car thermostat typically lasts around 100,000 miles or about 10 years. However, frequent driving in hot weather, heavy traffic, or stop-and-go conditions can strain the cooling system and shorten the thermostat’s life.
If your thermostat is nearing the end of its lifespan or showing warning signs, replacement is the next step.
How to Diagnose a Malfunctioning Car Thermostat and Replace It
Thermostat repairs can be tricky as the car’s cooling system operates under high heat and pressure. That’s why fixing a car thermostat issue is best left to a professional with specialized knowledge and tools rather than a DIY project.
Here’s how a mechanic will proceed:
- Open the hood and allow the engine to cool completely.
- Scan the vehicle using an OBD-II diagnostic tool to check for stored trouble codes. Codes such as P0128 may appear if the thermostat is stuck open, preventing the engine from reaching its normal operating temperature.
- Locate the thermostat housing, which is typically found where the upper radiator hose connects to the engine.
- Loosen the radiator cap and drain enough engine coolant so the level drops below the thermostat housing.
- Remove the thermostat housing bolts and lift off the housing. Take out the old thermostat and gasket.
- Clean the thermostat housing and engine mounting surfaces to remove any old gasket material.
- Install the new thermostat in the correct orientation. Keep the temperature-sensing cylinder (a wax-filled capsule that expands with heat to open the thermostat) aligned towards the engine.
- Place a new gasket and reinstall the thermostat housing.
- Tighten the thermostat housing bolts to the manufacturer’s specified torque.
- Refill the cooling system with the appropriate engine coolant and bleed the system to remove any trapped air.
- Run the engine until it reaches normal operating temperature. Observe coolant flow through the radiator, verify that the thermostat has opened, and check around the housing for any leaks.
- Clear any stored OBD codes.
- Test-drive the vehicle and confirm the engine maintains a stable operating temperature and the cooling system is functioning properly.
Now that you understand the process, you may be wondering how long this repair usually takes.
How Long Does a Car Thermostat Replacement Take?
In most vehicles, replacing a thermostat takes about 1 to 3 hours. However, in more complex engine designs, labor time can exceed 5 hours due to restricted access.
If you finally choose to replace the thermostat after weighing all the factors, there are several ways to keep the repair affordable.
How to Save Money While Replacing a Car Thermostat
Here are some practical tips to reduce the cost of thermostat replacement.
- Get estimates from multiple mechanics or auto repair shops to find the most competitive price.
- Shop online for a new thermostat to compare prices and related components before purchasing.
- Choose a quality aftermarket part, which is often more affordable than an OEM thermostat.
- If you’re already scheduling a coolant flush or radiator repair, ask if the thermostat replacement can be included at a discount.
Restore Your Engine Cooling System with AutoNation Mobile Service
A bad thermostat is one of those repairs that you should take care of sooner rather than later.
Luckily, AutoNation Mobile Service makes it easy. Our mechanics come to your location, seven days a week, and complete the repair right from your driveway. With upfront pricing and a 12,000-mile | 12-month warranty, you know exactly what to expect.