Car Running Hot but Not Overheating (Causes & Solutions)

Do you have a car running hot but not overheating problem and you would like to know why and how to fix it? If yes, you are on the right page.

Overheating of a car leads to great engine damage. The engine is capable of cracking and subsequently starts leaking oil under heat. All your cylinders, the piston can, and head gaskets can wrap up.

In the best-case scenario, some performance might be lost. Worst case, the whole engine could seize.

You can measure and control the temperature in your car using a temperature gauge. The gauge normally shows the average temperature, which is not too cold or hot. However, it’s scary to get an overheating warning from your car. If a hot engine is ignored, it could cause many problems.

Worst case, you’ll break down by the roadside with smoke from the engine.

It’s best to notice the problem on time to prevent it from getting worse and being excessively expensive to fix.

This article outlines why your car is running hot yet not overheating, and solutions for the problem will also be outlined. Read till the end for full enlightenment.

Sometimes, everything seems to be fine with the cooling system. These kinds of cases could simply be that the cooling system needs to be tuned up for it to work efficiently.

Changing the coolant could stop the problem of the car running hot. Below are a few reasons your car runs hot without overheating:

1. Faulty Temperature Gauge

Car Running Hot but Not Overheating

One of the common reasons you have a car running hot but not overheating is a faulty temperature gauge. Temperature gauges are made of a part that’s easily susceptible to damage. This factor is to be regarded as the last cause after you’re done investigating other things that might be the cause.

For example, when the gauge needle component is trapped in a hot section, it can be damaged easily. A sign that’ll likely show when this is the cause is that the gauge won’t give a steady reading.

If you don’t tighten the car’s radiator cap properly, the gauge can show inaccurate readings. However, you should note that a faulty temperature gauge can show a normal temperature when the engine is hot.

Also Read: Temperature Gauge Rising but Car Not Overheating (Causes & Solution)

2. Damaged Head Gasket

Another factor that could cause result in a car running hot but not overheating is a faulty head gasket. If you notice any blown head gasket signs, it means the gasket has formed a seal between the engine block and cylinder head.

The seal where the coolant, engine oil, and combustion chamber passes is not protected. A damaged Head casket can cause coolant to leak.

3. Faulty Engine Coolant Thermostat

A bad thermostat is another reason you might have a car running hot but not overheating. One of the coolant system’s very key components is the coolant thermostat of the engine. Most engines have more than one coolant thermostat, and they keep the engine’s temperature in check while operating in them.

The coolant thermostat of the engine acts as a gateway to the coolant system while controlling the flow of the liquid coolant whenever it becomes too hot.

The thermostat closes when the engine gets cold, keeping the liquid coolant flowing around the engine. However, immediately after the engine begins heating up, the thermostat is supposed to open up to let the coolant flow into the radiator, so it can cool before it returns back to the engine.

Over time, an engine thermostat could be less sensitive to temperature, and this can affect its performance.

When they no longer measure the engine temperature accurately, they start opening too late or too early. This affects the engine’s overall temperature because the coolant flowing to a radiator isn’t properly controlled. It can make the engine run hot yet not overheat.

Accessing the thermostat performance could be difficult when you’re not using a diagnostic reader that tracks the engine’s temperature at the correct time.

Fortunately, the engine thermostat is designed so that it’s left open when it fails. The thermostat remains open even when it fails completely and never blocks coolants from getting to the radiator.

4. Bad Water Pump

A bad water pump could be another reason why you have a car running hot but not overheating. The water pump serves as the cooling system’s major component. The cooling system won’t possess enough force to transport coolants through hoses or passages if the water pump doesn’t function correctly.

This could affect the whole engine’s cooling system, thereby making the engine hot. In addition, if floods or leaks affect the water pump, it could be responsible for the engine’s increase in temperature.

5. Bad Coolant Temperature Sensor

One important component of your cooling system is the coolant temperature sensor. It relays readings of temperature to the car’s temperature gauge.

A faulty coolant temperature sensor might prevent some necessary actions the ECU is supposed to take to prevent overheating or could cause the temperature gauge to show a false high temperature because the coolant is being prevented from circulating.

When an engine reaches two hundred and forty degrees Fahrenheit in most vehicles (one hundred and fifteen degrees Celsius), its cooling fan starts. The engine might overheat if the safety precaution fails.

6. Faulty Radiator Fan

Another reason you have a car running hot but not overheating problem is a faulty radiator fan. The car’s radiator fan helps decrease the coolant’s temperature as it gets heat from the engine. If it’s malfunctioning, the fan fails to accomplish the task, and it can affect an engine negatively by making the engine hot.

A Fluctuating radiator fan can make the car’s engine temperature fall and rise. This factor can make the temperature gauge readings fluctuate rapidly.

7. Low Coolant or No Coolant

A low coolant level can make the car’s temperature gauge show high-temperature readings. Insufficient coolant in the coolant reservoir can cause the engine to overheat because hot coolant circulation will be prevented.

Check your reservoir and top up if at a low level; ensure your coolant is always enough. A radiator flush may be needed to drain the old coolant. Consider your climate, and use the right coolant type.

8. Old Coolant

Old coolants are a common reason why you might experience a car running hot but not overheating. Most car manufacturers recommend you change your engine coolant every two years because, with time, an engine coolant’s ability to absorb heat energy and maintain engine temperature is lost.

Also, old coolant loses the ability to prevent the engine’s internal parts from rusting, and it’s so because additives in the coolant, like rust inhibitors, stop working after some time.

This could lead to debris and gunk building up in engine hoses and coolant passages. In addition, an unwanted material build-up in a coolant system could prevent coolant from flowing around the engine, making it hot.

Additives are also contained in engine coolants. These additives enhance the coolant’s thermogenic properties, which can degrade with time, reducing the coolant’s ability to absorb the engine’s heat.

9. Broken Hoses

A hose is a medium for transporting coolant. If heat exposure breaks it, coolant flow will be affected. A leaking hose won’t be capable of transporting coolant because coolants will escape and reduce, making it insufficient.

The problem is equally a factor to be considered if there’s a temperature increase in your car’s engine.

If you find out your car is overheating while the coolant in its reservoir is full, there’s a high possibility the hose is torn. Torn hoses reduce coolant levels drastically and cause coolant leakage.

Also Read: Car Overheating When Idle (Causes & Solutions)

How Do You Diagnose Engine Hot but Not Overheating Problems?

Car Running Hot but Not Overheating

  • Check if the coolant is leaking. Coolant leakage reduces the coolant, which will eventually make the engine run hot.
  • Check the radiator for damages or leaks. Check the radiator to ensure the coolant is not leaking out and no damage, which could stop the coolant flow, has occurred on the radiator fins. It’s advisable to perform a radiator flush, to remove all dirt build-ups.
  • Check the auxiliary cooling fan’s condition. Check the condition of the cooling fan for damage to the blades. Make sure it rotates freely (use a stick or screwdriver; don’t use your hands). Most fans are plastic and could lose or break their blades easily with time.
  • Check the conditions of the cooling system hose. Check for tears or splits that can let coolant escape on all the rubber system hoses. Check the joints of the hoses also, as they can often leak, especially if the hoses have shrunk or become hard.
  • Perform full system flush & coolant renewal. To remove debris and any partial blockage from the system. It’ll also let you add new coolants that act more effectively to maintain the engine’s temperature.

Also Read: How Far Can You Drive An Overheating Car?

How to Fix a Car Running Hot but Not Overheating?

When you notice your car is overheating, you could do the following things to prevent the engine from damaging.

1. Pull Over Immediately

It’s safe for you too. The major thing that can be done is to quit driving a hot car. If you pull over and shut down the car, you’re giving the car’s engine time to cool down and return to its regular temperature.

Watch your temperature gauge while waiting to make sure it’s going down. As it’s not advisable to continue driving at this point, you can call a car tow service or a friend.

2. Turn the Heat up and off the AC

Although it seems counterintuitive, a running AC can stress the engine more. You’ll pull the heat from the car’s engine into the vehicle when you turn the heat on. This option is great if you cannot pull over immediately and must continue driving a little more first.

3. Check the Coolant

When a car overheats in most situations, the problem is often related to leaking or low coolant. Check the level of your coolant immediately after you’ve pulled over safely. Top up the coolant if there’s some with you.

Check your owner’s manual if you’re unaware of the location of your car’s coolant reservoir.

After some time, start your engine when the car must have been done cooling down. Examining your temperature gauge ensures your car does not start overheating again.

If needed, this is the best time to drive carefully to the closest garage. While driving, keep examining your temperature gauge so you can stop if the car starts overheating again.

Check out this video for more tips on fixing an overheating car

Frequently Asked Questions – Car Running Hot but Not Overheating

Why is my car running hotter than usual?

If your temperature gauge constantly shows your engine’s warmer than it’s supposed to, check your cooling system ASAP. There’re many reasons why your engine’s running hot, and they include; a low coolant level, a closed or clogged thermostat, a malfunctioning water pump, or head gasket failure. 

Why does my engine feel so hot but not overheating?

There are a few reasons why you have a Car running hot but not overheating. They include; a damaged or clogged radiator, low coolant level, and damaged thermostat or water pump.

Why does my car smell hot but not overheating?

It’s because you might have tiny oil leaking out of the valve cover or any other place and leaking onto your exhaust. When it’s a sweet smell, like antifreeze, you’ll have small coolant leaks also. Lastly, check your wheels to determine if your brake is the smell source.

How can you tell if your water pump is not working?

When you turn off the engine, open the hood and find the water pump’s pulley. While wearing gloves, take it and shake it. There shouldn’t be any movements; if there are any, this noise indicates you might have problems with your water pump.

What sound does a failing water pump make?

If you hear a high-pitched whining sound, which increases while you accelerate, this can be a signal that you have a failing water pump. A loose belt causes the noise, and your belt gets loose if the pulley loosens or the bearing is wearing out.

What Is the Normal Temperature Gauge Reading of a Car Engine?

Usually, the car’s temperature gauge is an arrow that fluctuates between H for hot and C for cold. When your car is cool, the arrow should point at C. And when your car runs, the arrow is supposed to be around the middle. This is because the engine temperature, when it runs, normally is between 195 – 220 Fahrenheit.

Conclusion – Car Running Hot but Not Overheating

You should know that the engine is a car’s heart. Therefore, the condition of the car’s engine should be very important to you. Always check all the car components before turning the engine on and driving.

Also, ensure you run maintenance schedules for your car. Doing this can reduce, to a very large extent, the chances of the car developing issues that’ll cause engine problems or that will make the car run hot without overheating.

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