How do I know I need a new thermostat in my car?

Author: Mr. Mario Ritchie IV  |  Last update: Saturday, May 17, 2025

5 Signs Your Thermostat Is Broken
  1. You Notice Erratic Temperature Changes. ...
  2. You Find Incorrect Readings on the Temperature Gauge. ...
  3. Your Vehicle Makes Concerning Noises. ...
  4. You Find Coolant Leaks. ...
  5. You Notice Problems with the Heating System.

How can I tell if my thermostat is bad in my car?

If the engine runs too hot or cool, you might have a bad thermostat on your hands. You can check a thermostat for problems by examining the upper radiator hose's temperature after the engine has warmed up. You should replace a bad thermostat immediately and avoid driving without one until you get a replacement part.

What are the signs that indicate that a thermostat needs to be replaced?

Signs You Need a New Thermostat
  • Heating or cooling system will not turn off or on.
  • The temperature reading is incorrect.
  • Recent spike in your energy bill.
  • Frequent temperature fluctuations.
  • Thermostat is 10 years old or older.

Can a car run with a bad thermostat?

A: The thermostat, or lack thereof, will not prevent the car from running, it only prevents it from maintaining the correct operating temperature and proper operation of the engine control, more pollution, lower efficiency (burn more fuel) and possible emission control system damage.

When should I replace my car thermostat?

A car thermostat typically lasts between 10 to 15 years, or about 100000 to 150000 miles, depending on the vehicle and driving conditions. However, factors like engine temperature, coolant quality, and maintenance practices can affect its lifespan.

SYMPTOMS OF A BAD THERMOSTAT

How much does it cost to replace a car thermostat?

The average cost for car thermostat replacement is $661 to $747. Enter your vehicle's information to see how much thermostat replacement costs in your local area.

How far can I drive with a bad thermostat?

The furthest you can drive an overheating car is about a ¼ mile before you risk irreversible engine damage. While some vehicles could still make it as far as 20 miles, we would never recommend driving very far with an overheating engine.

How do I know if my thermostat is faulty?

A bad thermostat can be detected when your AC or furnace is not turning on, your HVAC systems are not turning off, the thermostat not responding, your HVAC system is short-cycling, the room temperature not matching the temperature displayed on the thermostat, and the programmed setting resetting themselves.

What is the lifespan of a car thermostat?

However, most car experts recommend car thermostat replacement after 10 years. However, this is an optimistic number. Thermostats are more likely to stop working much earlier than a decade. Some factors that induce an early thermostat failure include harsh weather, rough driving, bad engine or thermostat parts.

Will a bad thermostat throw a code?

While there is a small chance that there is an issue with the running temperature of your engine, by far the most common issue with trouble code P0128 is a faulty thermostat. The exact location of the thermostat and issues related to a damaged thermostat may vary depending on your vehicle.

How do I check my thermostat?

Methods for Testing Your Thermostat
  1. Just Turn it On and Let it Work. One way to test your thermostat is to simply turn it on and see if it cools the room down. ...
  2. Get an Indoor Thermometer. Another way to test your thermostat is to use a thermometer. ...
  3. Use a Multimeter. ...
  4. What to Do if You Notice an Issue.

What are the symptoms of a thermostat not opening?

High temperature readings

The main symptoms of a failing thermostat are related to engine overheating. It can be easily noticed because the temperature gauge in the vehicle will probably read unusually high. This can be caused by the valves being stuck in a closed position.

Can I replace my thermostat myself?

In most cases, installing a new thermostat is a relatively simple do-it-yourself project that can result in improved comfort and convenience and one that can help you save energy.

How can I tell if I need to replace my thermostat?

If your thermostat has fresh batteries but suddenly lacks power, flashes, or isn't responsive to adjustments, it may need replacement. If resetting the thermostat doesn't resolve the problem, you may have wiring problems or faulty components causing your thermostat to not turn on.

How do I know if my water pump or thermostat is bad?

Here are signs you've got a bad pump or thermostat.
  1. Corroded Cooling System Parts. Both of these cooling system parts can get corroded if they start to leak slowly. ...
  2. Leaking Engine Coolant. ...
  3. Erratic Temperature Changes. ...
  4. Poor Coolant Circulation. ...
  5. Overheating Constantly.

What damages car thermostat?

Corrosion occurs, among other things if a wrong coolant is used. The corrosion attacks the thermostats aluminum parts that almost "etch away" (see figures 1 and 2). But also mixing of different coolants can cause corrosion. Therefore avoid mixing different types of coolant together.

How can I tell if my cars thermostat is bad?

5 Signs Your Thermostat Is Broken
  1. You Notice Erratic Temperature Changes. ...
  2. You Find Incorrect Readings on the Temperature Gauge. ...
  3. Your Vehicle Makes Concerning Noises. ...
  4. You Find Coolant Leaks. ...
  5. You Notice Problems with the Heating System.

How many hours does it take to replace a thermostat in a car?

Car thermostat replacement time is 30 to 60 minutes, depending on the make of the car. It will cost you around $190 to $350, including labor. Thermostat repairs usually take more time, requiring extra time to diagnose and analyze the vehicle's thermostat. It can take up to 2 hours.

How much does it cost to replace a thermostat in a car?

The average cost for a Thermostat Replacement is between $512 and $550. Labor costs are estimated between $129 and $163 while parts are priced between $382 and $387. This range does not include taxes and fees, and does not factor in your unique location. Related repairs may also be needed.

Can you drive a car with a faulty thermostat?

If you drive with a bad thermostat, your car could overheat, causing severe and expensive engine damage. And while it's technically possible to drive without a thermostat, we don't recommend it. Your car will not reach an acceptable operating temperature, resulting in higher fuel consumption and excessive engine wear.

How do I know if my thermostat or sensor is bad?

Symptoms of bad temperature sensor
  1. Erratic Readings. Sudden jumps or drops in temperature readings. ...
  2. Open Circuit: Display shows a very high or infinite temperature. ...
  3. Short Circuit: Display shows a very low or negative temperature. ...
  4. Drift: ...
  5. Noise or Interference: ...
  6. Physical Damage:

How to unstick a car thermostat?

This is an easy problem to solve yourself by simply removing the plastic outer casing and, with a very soft brush, delicately brushing off its coil and contact surfaces. It is most effective to clean the thermostat first at its lowest setting, then again at its highest setting.

Is there a code for a bad thermostat in a car?

Error code P0128 indicates that your engine coolant temperature is below the thermostat regulating temperature. This means that your Engine Control Module (ECM) or Powertrain Control Module (PCM) has recognized that your engine is running cooler than it's supposed to.

How to tell if an engine is damaged from overheating?

The main symptoms of engine damage from overheating include:
  • Thumping or knocking noises.
  • Reduced power.
  • A burning smell.
  • Smoke or steam.
  • A bonnet that is hot to the touch.

How urgent is a thermostat replacement?

HOW IMPORTANT IS A THERMOSTAT SERVICE OR REPAIR. It is never good to have an over-heating engine. Delaying replacement of the engine thermostat and continuing to drive the car can only result in far more costly engine repairs or replacement.

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