What are the reasons for the engine temperature not rising?

[DeAriana]

Engine temperature not rising reasons are as follows: Thermostat failure: The performance of the car's cooling system is closely related to the engine water temperature, including the radiator, cooling fan, water pump, thermostat, water jackets, and water pipes. Problems with the cooling system often pose a high-temperature risk to the engine. For example, if the cooling fan stops working or the water pump fails, the coolant (antifreeze) cannot dissipate heat properly, causing the engine temperature to rise and the coolant to "boil". Water temperature sensor failure: If the engine water temperature does not rise, it may be due to a water temperature sensor failure (the sensor interrupts the temperature signal to the dashboard). A malfunctioning water temperature sensor prevents the temperature gauge needle from working correctly, creating the illusion that the water temperature is not rising. Even if the engine water temperature is very high, the temperature gauge will not respond.

[PaigeRose]

My car's temperature gauge remains low after driving for a while in winter. I suspect the issue lies with the thermostat stuck in the open position. It should close when the engine is cold to allow the engine to warm up, but if it's faulty, it keeps the coolant circulating continuously. Another possibility is a malfunctioning coolant temperature sensor, displaying incorrect temperatures. Insufficient coolant levels or air trapped in the system, forming bubbles that hinder heat transfer, could also be the cause. Extremely cold environments or abnormal fan control may lead to slow temperature rise. If not addressed promptly, engine wear accelerates, combustion efficiency drops, fuel consumption increases, and long-term damage to the engine may occur. Simple checks: Start the engine and see if the heater blows hot air—if not, it indicates a heating system issue; check the coolant level. If you're not confident in handling it yourself, take it to a professional repair shop for diagnosis as soon as possible. Replacing parts isn't expensive, but ignoring the problem carries significant risks.

[Betty]

I've encountered a similar situation before. After driving for half an hour, the heater still wasn't warming up. It turned out the thermostat was faulty—it's supposed to control the coolant flow to assist with heating. Additionally, a malfunctioning coolant temperature sensor can mislead the computer, causing the temperature display to read lower than actual. Air bubbles in the coolant or insufficient coolant levels reduce heat dissipation efficiency. Internal engine issues, such as cylinder wear, lower heat transfer efficiency, resulting in slower temperature rise. If not repaired promptly, fuel consumption increases noticeably, and driving in winter becomes uncomfortable. I recommend first checking the coolant's color and level—cloudy color indicates aging and the need for replacement. After starting the engine, listen to see if the fan is operating normally. If you can't figure it out, visit a 4S shop. They can perform more accurate diagnostics with specialized tools. Don't delay too long to avoid engine damage.

[StKingston]

The engine temperature always fails to rise. Common causes include a faulty thermostat stuck in the open position, causing coolant to flow too quickly and preventing the water temperature from increasing. Alternatively, there might be an issue with the water temperature sensor, which falsely reports low temperatures. Problems in the cooling system, such as a clogged radiator or leaks, can also affect heat exchange. In older vehicles, poor engine sealing may lead to excessive heat loss. The issue worsens in cold weather. Prolonged driving under these conditions accelerates engine wear, increases fuel consumption, and reduces heating efficiency. Inspection methods: Monitor the dashboard gauges while driving; if slow heating is noticeable, consider replacing the thermostat. Ensure the coolant is fresh and free of air bubbles. If there's no improvement, seek professional repair promptly to prevent minor issues from escalating into major faults.