How do I know if my motorcycle thermostat is bad?

Asked By: Orreaga Oldermann | Last Updated: 17th March, 2020
Category: home and garden indoor environmental quality
4.2/5 (741 Views . 13 Votes)
There are several common symptoms associated with a bad or failing thermostat that will alert you that service is due.

Symptoms of a Bad or Failing Thermostat
  1. Temperature gauge reading very high and engine overheating.
  2. Temperature changing erratically.
  3. Coolant leaks around the thermostat housing or under the vehicle.

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Accordingly, what happens when thermostat is stuck closed?

If the thermostat becomes stuck in the closed position, the circulation of the coolant is blocked so the coolant cannot get to the radiator to be cooled which causes the engine to overheat.

Subsequently, question is, can a bad thermostat cause pressure? Thermostat. When the radiator stops working correctly, too much pressure is put on the thermostat, often causing it to stop working. When the thermostat fails, the valve inside gets stuck either open or closed. With a closed thermostat, your engine will immediately start to overheat.

Just so, how do you check if the thermostat is working in your car?

Start your car's engine and allow it to idle. Look through the radiator filler neck to see if the coolant flows. At this time, it should not be flowing as your car has not reached the operating temperature to cause the thermostat to open. If you find the coolant is flowing, it means the thermostat valve is open.

How does an engine coolant thermostat work?

Its job is to block the flow of coolant to the radiator until the engine has warmed up. Once the engine reaches its operating temperature (generally about 200 degrees F, 95 degrees C), the thermostat opens. By letting the engine warm up as quickly as possible, the thermostat reduces engine wear, deposits and emissions.

33 Related Question Answers Found

How can you tell if your thermostat is stuck?

Symptoms of a Bad or Failing Thermostat
  1. Temperature gauge reading very high and engine overheating. The first and potentially most alarming symptom will be the temperature gauge reading high into the red within the first 15 minutes of your vehicle engine running.
  2. Temperature changing erratically.
  3. Coolant leaks around the thermostat housing or under the vehicle.

How do I know if my thermostat is broken?

The most common signs of a broken thermostat are:
  1. Thermostat display is off or is non-responsive.
  2. Turning on the heat or AC does nothing.
  3. The heat or AC will come on, but either stays on nonstop or cuts out before the temperature setting is reached.

How can you tell if your engine coolant temperature sensor is bad?

Symptoms of a bad or failing coolant temperature switch (sensor)
  1. Poor fuel economy. One of the first symptoms associated with a problem with the coolant temperature sensor is poor fuel economy.
  2. Black smoke from engine. Another symptom of a possible problem with the coolant temperature sensor is black smoke from the vehicle's exhaust.
  3. Overheating engine.
  4. Check Engine Light comes on.

Can I remove thermostat to stop overheating?

TOM: Yes, Lee, removing the thermostat does make the car run cooler. But you should never, ever do it. When the engine is too cool, the thermostat closes and stops the coolant from flowing through the radiator, so the engine heats back up.

Can a bad thermostat cause furnace not to work?


Faulty Wiring
Loose or missing wire connections, and faulty or aged wires can cause your thermostat to lose its connection to your heating and cooling systems, thereby causing an interruption in service. If your furnace stops working properly, it's a good idea to inspect your thermostat's wiring.

Why is my car overheating but it has coolant in it?

A common cause of car overheating is a low-cost thermostat stuck closed, restricting coolant flow. A blown head gasket can be the cause or the result of car overheating issues. Coolant can leak out, air gets sucked in, and the engine temperature needle wraps around to full hot. Plugged heater core.

How long does a car thermostat last?

Unless an engine overheats or fails to reach normal operating temperature after being driven for several miles, the thermostat that regulates the flow of coolant is probably working properly. Thermostats generally last for years — even for the lifetime of a vehicle — so why bother changing it?

How much does a thermostat cost?

For a standard, 2,000-square-foot home, the cost of installing or replacing a thermostat averages between $112 and $250, including the price of the unit and professional installation. The national average cost is $171. The thermostat will run between $15 and $300, depending on the type and its features.

When should I replace my car thermostat?


Waiting until it fails can multiply the repair cost exponentially (an overheated engine might need internal repairs costing thousands of dollars) The thermostat can, and should, be replaced when performing other cooling system service work, such as replacing the water pump or radiator hoses, or flushing the coolant.

Can radiator stop leak cause overheating?

Car Overheating. Is your car overheating? Our Bar's Leaks Liquid Aluminum Cooling System Radiator and Heater Core Stop Leak is scientifically formulated to permanently seal coolant leaks that are the cause of most overheating problems.

Which way does coolant flow through an engine?

The coolant flows through the thin, flattened tubes that make up the core of the radiator and is cooled by the air flow through the radiator. From there, it flows out of the radiator, through the lower radiator hose, and back to the water pump.

How do you know if your car thermostat is working?

Start your car's engine and allow it to idle. Look through the radiator filler neck to see if the coolant flows. At this time, it should not be flowing as your car has not reached the operating temperature to cause the thermostat to open. If you find the coolant is flowing, it means the thermostat valve is open.

What happens when your thermostat is stuck closed?

If the thermostat becomes stuck in the closed position, the circulation of the coolant is blocked so the coolant cannot get to the radiator to be cooled which causes the engine to overheat.

What causes a radiator to build up pressure?


When the fluid in the cooling system heats up, it expands, causing the pressure to build up. When the radiator cools back down, a vacuum is created in the cooling system that pulls open another spring loaded valve, sucking water back in from the bottom of the overflow tank to replace the water that was expelled.

Can a bad thermostat cause coolant overflow?

Thermostat. Most of the rest of these problems will cause a check engine light to turn on, but they could have an issue and not be noticed by your vehicle's computer. A bad thermostat can improperly regulate fluid, and can lead to overflow.

How do I know if I need a new radiator?

5 Signs you Need Radiator Repair
  1. Temperature Gauge Reads Hot. If the needle on the temperature gauge in your dashboard constantly points to hot there is likely some sort of issue.
  2. Overheating. One of the most obvious signs of radiator trouble is if your vehicle actually overheats.
  3. Radiator Discoloration or Rust.
  4. Low Coolant Levels.
  5. Coolant Leak.