What Happens When the Thermostat is Stuck Open? Answered

Have you wondered what happens when the thermostat is stuck open? You are not alone. It’s a common question, but getting an answer isn’t always easy. However, here is a short answer;

The thermostat will be stuck open if too much coolant circulates into your radiator, causing your engine to run cold.

Here’s what happens and how to fix it.

What is a Vehicle Thermostat?

A vehicle thermostat is a device that controls the engine coolant flow to maintain the engine operating temperature within the ideal range.

The engine thermostat usually consists of a brass housing with a wax pellet that melts and expands when heated. It causes a plunger inside the housing to open a valve, allowing the engine coolant to flow through.

The wax contracts when the engine has cooled down, and the plunger closes the valve, preventing coolant from flowing.

Thermostats are generally designed to open at 195 degrees Fahrenheit, but different engines have ideal operating temperatures. As a result, thermostats are available at various opening temperatures.

Vehicle thermostats play an essential role in maintaining proper engine operating temperature. Engines that are stuck open will run cooler than normal.

What Causes a Thermostat to Get Stuck Open?

Your engine will run cold if you circulate too much coolant into your radiator, and the thermostat will be stuck open.

The thermostat can also become stuck open due to debris and dirt. Over time, rust and scale can build up on the thermostat housing and prevent the thermostat from seating properly.

A corroded thermostat can also get stuck open. Over time, the metal components in the thermostat can become corroded due to exposure to moisture or humidity.

Because of corrosion, internal parts cannot move freely, resulting in a stuck thermostat. In some cases, a faulty or incorrect thermostat is the cause. It can cause the engine to run too cool or overheat.

What are the Symptoms of a Stuck Open Thermostat?

The symptoms of the stuck thermostat being open are:

Engine Temperature Gauge Reading is Lower than Normal

The first and most common indication of a jammed thermostat is lower-than-average engine temperature gauge readings.

A properly operating thermostat will maintain the engine coolant at the ideal temperature, usually around 195 degrees Fahrenheit.

If the thermostat is stuck open, the engine coolant will not be able to reach this temperature. As a result, the engine temperature gauge will read lower than expected.

Frequent Engine Overheating

A stuck open thermostat can cause overheating of the engine. If the engine coolant cannot reach the ideal operating temperature, it will cause the engine to overheat.

It is because the engine needs the ideal operating temperature to function correctly. Without it, the engine will start to overheat and eventually shut down.

Poor Fuel Economy

Poor fuel economy is often a symptom of a stuck open thermostat. When the thermostat stays open, the engine coolant circulates through the engine constantly, even when the engine is cold.

It causes the engine to run cold, resulting in poor fuel economy. Poor Fuel Economy.

Check Engine Light is On

If the check engine light comes on, it could mean that the thermostat has become stuck open. The check engine light can show a variety of different engine problems.

How to Fix a Stuck Open Thermostat?

First, check the coolant level in your radiator. If it’s low, add more coolant until the level is full.

Next, locate the thermostat and remove it from the housing. Make a note of the position of the thermostat before removing it so you can replace it the same way.

After removing the thermostat, look for a stuck valve. If so, clean off any debris that may be causing it to stick and then reassemble the thermostat.

The problem may be with the thermostat if the valve is not stuck open. In this case, you’ll need to replace the thermostat with a new one.

How Do I Install a New Thermostat?

Installing a new thermostat is reasonably straightforward. After removing the old thermostat, reinstall it in the same position as the old one.

Once the new thermostat is in place, add more coolant to the radiator and start the engine. Let it run for a few minutes to check if the temperature gauge reading is back to normal.

To avoid injury, it is best to let the engine cool down before changing the thermostat.

If you’re still having trouble with your engine temperature, it’s best to take it to a mechanic for further diagnosis.

Can I Drive My Car with the Thermostat Stuck Open?

It is not recommended to drive a car with the thermostat stuck open. Driving with a stuck open thermostat can cause engine damage because it cannot reach its ideal operating temperature.

It can also lead to poor fuel economy and increased emissions. If possible, the safest to do is to have the thermostat fixed as soon as possible.

Why is Thermostat Important in My Car?

The thermostat is essential in your car because it regulates the temperature of the engine coolant.

The thermostat closes when the engine is cold, allowing coolant to remain in the engine block and warm it up. When the engine reaches operational temperature, the thermostat opens, allowing coolant to flow through the radiator and cool it.

The engine will overheat because the coolant cannot flow when the thermostat is stuck closed.

Since the coolant is repeatedly poured through the radiator, an open thermostat will result in the engine running cold.

Conclusion

The thermostat is vital in your car because it regulates the temperature of the engine coolant. The thermostat closes when the engine is cold, allowing coolant to remain in the engine block and warm it up.

When the engine achieves operational temperature, the thermostat opens, allowing coolant to flow through a radiator and cool it.

A stuck open thermostat can cause engine damage because it cannot reach its ideal operating temperature. It can also lead to poor fuel economy and increased emissions. If possible, the safest thing to do is to have the thermostat fixed as soon as possible.