Why is the temperature gauge rising if my car isn’t overheating?
A rising temperature gauge is worrying and indicates a possible overheating problem. But surprisingly, your engine can run hotter than normal without actually overheating.
Let’s look at some possible reasons (not all of which are serious) that your engine operating temperature may be rising without an actual overheating occurring, as well as what to do if you notice a rising temperature gauge.
Why your car is hot but not overheating
Due to a variety of reasons, your vehicle’s engine may get hot but not overheat. Understanding the possible causes of such issues can help you when solving the problem at hand.
Here are some of the most likely causes of a gradual increase in engine temperature:
1) Water Pump Failure
If your car’s engine is running hotter than normal but isn’t actually overheating, a faulty water pump may be to blame. Your engine’s water pump typically circulates coolant between your vehicle’s radiator and the engine block itself. However, if the water pump impeller is damaged, this circulation may not occur properly.
2) Stuck Thermostat
A partially stuck thermostat can prevent coolant from circulating properly, causing the engine to run hotter than normal. If the thermostat is stuck between the fully open and fully closed positions, it no longer serves as much as a restriction for the cooling system.
In this condition, heat cannot be properly exchanged between the engine itself and the vehicle’s radiator. Fortunately, the cost of replacing a thermostat is usually relatively low.
3) Clogged Cooling System
Similar to the stuck thermostat example mentioned above, a clog or restriction in your engine’s cooling system can cause your vehicle to run hotter than normal.
This condition most commonly occurs when your vehicle’s radiator becomes clogged with rust or other debris. A crushed radiator hose can produce similar results.
4) Engine Fan Doesn’t Work
The job of your engine’s cooling fan is to distribute airflow across the surface of your vehicle’s radiator. Because of this, a faulty radiator fan or fan relay can cause your engine to run hotter than normal, which can cause problems. In such cases, the fan must be replaced or its control circuit repaired to restore the correct temperature values.
5) Blown Head Gasket
A blown head gasket can cause the engine to operate at a higher temperature than normal. This is often caused by loss of coolant due to leakage between the cylinder and the cooling jacket.
However, a blown head gasket can allow combustion gases to enter the engine’s cooling system, causing a significant increase in operating temperatures.
6) Low Coolant Level
In many cases, a slight increase in engine operating temperatures can be the result of nothing more than a low coolant level in the engine’s radiator. This occurs when there is one or more leaks in the engine’s cooling system, even if they are relatively minor. In this case, there is simply not enough coolant remaining to ensure proper engine cooling.
7) Faulty Temperature Sensor or Display
In some cases, your vehicle’s engine may not be hotter than normal even though your vehicle’s temperature gauge indicates that it is running hotter than normal. A faulty temperature sensor or gauge can give false feedback and make you think there is a problem when in fact there is not. What to do if you notice your temperature gauge is rising?
Overheating Temperature Indicator
If you notice that your car’s temperature gauge is rising, pull over to the side of the road and park. Even if your engine is not currently overheating, irregularities in operating temperature may indicate further temperature-related issues. Once the engine has cooled, you can drive it to your home or to a nearby service center.
- If you notice that your engine’s operating temperature is not regulating as expected, it is always important to take all possible preventative measures.
- If such an issue worsens and eventually leads to overheating, it can cause serious damage to your engine.
- If your engine overheats, it can cause a blown head gasket, a warped cylinder head, or a cracked block.
If you are unsure whether you can diagnose such a problem yourself, you should schedule an appointment with an independent mechanic or dealership service center as soon as possible.
Do some vehicles run hotter than others?
The reason why some vehicles run hotter than others has to do with the temperature rating of the engine thermostat. This special component controls the flow of coolant between the engine’s block/cylinder head and the vehicle’s radiator.
Thermostats come with a variety of pre-set temperatures that indicate the temperature at which the thermostat will automatically open, allowing flow and heat transfer. The higher the thermostat’s temperature rating, the hotter the engine will run.
Manufacturers select specific thermostats based on the ideal temperature needed for efficient combustion. The temperature reading will increase when: driving uphill, idling, or with the air conditioning on
If any of the above conditions cause the engine temperature to rise above normal, an inadequate cooling system is almost always the cause. Nothing puts as much strain on the engine’s cooling system as driving up a steep hill, driving with the air conditioning on, or idling for long periods of time.
In many cases, this is due to a general lack of coolant due to one or more leaks in the system. However, a clogged cooling system can also cause similar problems.
Another likely culprit behind overheating during periods of heavy load is a faulty cooling fan. Without a functioning cooling fan, an engine is largely unable to regulate its operating temperatures as would otherwise be possible.
