What causes lower than normal engine temperatures?

A blue light often indicates lower than normal engine temperatures.

If you’ve ever had to start your car on a cold morning, you will know the effect that cold temperatures have on your engine. Your car’s engine needs to reach an optimum temperature in order to run correctly. In most cars, this temperature is around 90°C.  Failure to reach this temperature results in decreased engine power and efficiency. Low engine temperatures are usually caused by a problem in the car’s cooling thermostat or cooling system.

Learn more about how the cooling system works >

Your car’s cooling system is designed to prevent the engine from overheating. It does this by pumping coolant through your engine to reduce its running temperature. If too much coolant flows through your engine, it will fail to reach its ideal operating temperature. The temperature of your engine can be monitored via the temperature gauge on your dashboard. If it stays lower than normal for a prolonged period of time, you should have your cooling system inspected for issues. For example a typical engine should reach about half way on the temperature gauge on the dash after 5 to 10 minutes normal driving. If the engine temperature gauge on the dashboard reads say 1/3 or less after 5 to 10 minutes then your engines cooling system thermostat could be stuck open, or there could be an issue with the engine temperature gauge, its wiring, or the coolant temperature sensor used for the engine temperature gauge.


Common causes:

  • Thermostat stuck open – The thermostat is used to regulate engine temperature. It does this by opening and closing to let coolant into the engine. If the thermostat becomes stuck open, too much coolant will enter the engine, resulting in engine temperatures decreasing.
    Thermostat replacement in Hamilton
  • Faulty temperature sender unit – On some modern engines the temperature sender unit monitors engine temperature and tells the thermostat when to open and close. An inaccurate or inconsistent reading can lead to the thermostat remaining open and bringing down engine temperature.
  • Radiator fan issues – The radiator fan reduces coolant temperature, allowing it to continuously cool the engine. Sometimes, the radiator fan can become stuck on due to faulty sensors or internal issues. This can lead to a gradual decrease in engine temperature.
  • Faulty temperature gauge – Sometimes, the temperature gauge can give a low reading, even when the engine temperatures are normal. This happens due to faulty sensors or incorrectly installed gauges.


Symptoms of low engine temperature:

  • Reduced engine performance – A cold engine will struggle to accelerate, stutter and sometimes stall while you are driving.
  • Increased fuel use – Low engine temperatures will also affect your car’s fuel consumption. This is due to non-optimal running temperatures.
  • Low-temperature warning light – Some cars have a warning light which will illuminate if engine temperatures are lower than normal.
  • Check Engine Light On – on some modern cars, the engine car computer monitors the engine temperature over time, and will set a stuck open thermostat fault code and turn the Check Engine Light (CEL) on to warn the driver.
  • Increased Exhaust Emissions – an engine that runs too cold is less efficient and will not completely burn all of the fuel correctly resulting in a dramatic increase in harmful green house gases from the exhaust.


Thermostat / Cooling System Diagnostics & Replacement in Hamilton

Have you been experiencing low engine temperatures? If so, we can help! At Grimmer Motors, our team of skilled mechanics can diagnose and fix problems in your car’s cooling system. Whether it’s accurately measuring your engines actual temperature with electronic thermometers, installing a new thermostat, replacing the temperature sensors, preventing radiator cooling fans from staying constantly on or fixing a faulty engine temperature gauge on your, we’re happy to help.

For low engine temperature inspections in Hamilton, contact Grimmer Motors today!


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