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Temperature Gauge High but Car NOT Overheating


When the temperature gets into the “red zone”, you have a right to be worried! What to do? First of all, stop driving, turn off the engine and wait for it to cool down! Also, make sure the air conditioner is turned off and the windows are open.

Examine the temperature gauge to see whether it begins to fall after you’ve turned off the engine and other car equipment. If nothing happens, you’ll need to visit your local dealership to have the issue diagnosed. It’s critical that you figure out what’s going on and get it fixed!

If you discover that your temperature gauge goes sky-high, but you can’t feel it in your car, maybe it’s time to replace your gauge. The same goes if your reading is getting into the “cold zone” while the car is running or idling. If you examine the radiator cap and see that it isn’t properly closed, you just found your problem and it’s easy to solve!

Most drivers never check the temperature gauge, yet it is highly important in determining if your vehicle is NOT overheating! If the temperature gauge is high, the engine may be overheating and you aren’t even aware of it!

If your car’s mileage begins to plummet, it’s possible that the temperature gauge has to be replaced. Some cars have temperature gauges that are wired differently than others. Their coolant temperature sensor has two wires leading to the cluster.

Modern vehicles use an engine control unit that calculates the proper air-fuel mixture at various temperatures from the coolant temperature. The coolant temperature sensor’s wires first go to the engine control unit, and then the information is directed to the cluster.

You must ensure that the coolant level is maintained because low coolant or oil might cause the engine to overheat. Continued driving when your car is overheating can create additional wear on the engine, reducing its longevity.

Why would temperature rise?

The coolant temperature is indicated by the gauge in most automobiles, and it can provide the driver a rapid warning regarding the coolant system. Your engine should be running at a typical temperature of 195°F to 220°F, and anything above that is considered a “red zone”.

Your temperature could raise for two main reasons. Either your engine is overused or the gauge is broken.

1. Rough terrain or driving

It’s possible that the temperature gauge will rise if the engine has been overworked. If you’ve been driving for too long, on rocky terrain, or if you’ve been accelerating for a long time, the engine can become overworked.

You will need to come to a complete stop and allow the engine to cool down, before going further. After the engine has cooled down, you can resume driving (assuming that the vehicle is no longer giving your “hot” readings).

2. Poor gauge maintenance

Temperature gauge problems can occur if your car is not properly maintained. To keep your vehicle in good shape, you should perform routine maintenance on it, which includes checking the temperature gauge.

When the temperature gauge isn’t kept up to date, it can display inaccurate values, which can also reduce your mileage. This problem can be expensive to fix, and you could have avoided it if you had maintained your vehicle properly.

Why is your car not overheating?

The temperature gauge should be around the middle and not running hot with the running engine in normal conditions. If you wish to fully diagnose this issue, you can use a professional OBD2 scanner and get the most accurate reading.

When an issue like this occurs in the vehicle, an error code is communicated to the diagnostics unit. This diagnostics unit will be read by an OBD2 scanner, which will display the problem codes stored within.

The error code will then be translated by the professional diagnostics program, and you will know the meaning of it. If there’s an issue with the temperature gauge, you’ll know exactly what’s wrong and how to correct it.

Here is what could possibly be wrong with your car:

1. Temperature sensor failed

In this scenario, we’re specifically talking about the coolant temperature sensor. The coolant temperature sensor performs precisely what its name implies:

  • It detects the temperature of the coolant
  • It communicates that information to the car’s computer (which then uses that information to adjust the air-to-fuel ratio and ignition timing).

Sometimes when the temperature sensor fails, your temperature gauge may display a high reading even if the coolant temperature isn’t that high.

If the computer receives an inaccurately high-temperature signal, it may alter the air to fuel ratio to be significantly leaner than typical and that can actually cause the engine to overheat!

If the sensor becomes contaminated with dirt and debris, it may start acting up like this and causing problems. In this case, the sensor is not triggered by excessive heat, but it actually created an overheating situation.

Your sensor will probably need to be replaced:

2. Temperature gauge is broken

You definitely need to know what temperature you have at all times and if the gauge itself is broken, that could be a problem. If your temperature gauge is giving you an erroneous reading, maybe it’s time to change it!

The gauge breaking isn’t something that happens all the time, but it can happen. If your temperature gauge is malfunctioning, you will NOT know the exact temperature of your engine coolant, and you will get false readings.

To determine how accurate your gauge is, you may need to examine other components of your engine first. First of all check the coolant levels, as it is the first signal that your engine may be really overheating.

Then compare the temperatures of the engine and the radiator hose. Radiator hose CANNOT be cool in comparison to the hot working engine and that could mean that the water pump isn’t working or the radiator is clogged.

You should also check for any coolant leaks near the engine. If you’ve established that your engine is operating normally but your temperature gauge continues to register high, you can try changing the gauge:

3. Engine Control Unit (ECU) is broken

A malfunctioning Engine Control Unit might cause the temperature gauge to rise even if the car isn’t hot. The reason for this is that the temperature gauge is receiving incorrect data from the Electronic Control Module (ECM). This is a rare occurrence, though.

You may want to double-check this with an OBD2 scanner and look for any fault codes that return temperature information. A mechanic will need to check this out if you find problems.

4. Dirty or corrosive connectors

If you discover corrosion on the connectors of your sensor, cluster, or ECU, all you have to do is to clean them. Brake fluid can be used for cleaning.

5. Damaged wiring

Broken wires to the sensor or gauge might cause the temperature gauge to display the incorrect temperature. You should inspect wires between sensor, cluster, and ECU

6. Head gasket failure

Between the engine block and the cylinder head, the head gasket creates a seal. Its function is to contain the combustion gases inside the cylinders and to prevent coolant or engine oil from flowing into them.

Head gasket failure can cause your temperature gauge to show that high reading, even though your engine is NOT overheating. All your seals should be properly checked by a professional and if the gasket did create a problem, it should be replaced.

7. Clogged radiator

A clogged radiator is another possible reason for a high engine temperature gauge reading. If your radiator is blocked or rusted, it can cause an engine to heat up when idle but cool down when the car is driving.

Using low-quality coolant may clog your radiator. If the damage isn’t too severe, you might be able to fix the problem by draining your cooling system and refilling it with a fresh coolant.

8. Water (coolant) pump failure

Your car’s water pump’s job is to circulate cooling fluids throughout the engine. When the water pump fails, the engine will soon heat up while idling.

However, after the car is moving, you may notice that the temperature returns to normal. This is most likely due to the greater airflow generated by a fast car compensating for the absence of coolant circulation.

Hope this helps, and if it doesn’t, you know where to go…

Attention! This article is for informational purposes ONLY and is NOT a replacement for professional advice! ALWAYS consult your local specialist for an appropriate solution to your problem. All statements, prices, contact information, recommendations, and reviews contained herein came from sources that we believe to be reliable, but the accuracy or completeness thereof is not guaranteed. Please contact the service provider for complete details and updates.

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