Idle running is a common problem with many cars, and it can cause problems down the road. A coolant temp sensor can help you diagnose and fix the issue.
What is a Coolant Temp Sensor?
A coolant temperature sensor alerts the engine control unit (ECU) when the coolant temperature falls below a certain threshold. This prevents the engine from running too lean at idle, which can cause problems such as reduced fuel economy and decreased performance.
Most cars use a thermostat to regulate the coolant temperature. When the thermostat senses that the coolant has warmed up, it opens the valve to let more heat out. When the coolant temperature falls again, the thermostat closes the valve, keeping the coolant at a set temperature.
If your car doesn’t have a thermostat, or if it malfunctioned, your car may still use a coolant temp sensor. The ECU will use this information to adjust fuel mixture and timing to maintain a set coolant temperature.
How Does a Coolant Temp Sensor Work?
A cooling system temp sensor is a small, electronic device located in the engine block near the thermostat. The sensor measures the coolant temperature and sends a signal to the engine control module (ECM) to adjust fuel delivery, air flow, or both.
One common use for this sensor is to optimize the fuel mixture at idle. When the engine is cold, the air/fuel mixture is richer than when it is warm, so the ECM will adjust the fuel mixture to run more efficiently at idle. However, if your car’s coolant temp sensor isn’t functioning properly, it could cause your car to run lean at idle. This can result in decreased performance and increased emissions.
If you’re having trouble starting your car in cold weather and think your coolant temp sensor might be causing it, take your car into a local mechanic for a diagnosis. If it’s determined that your sensor is malfunctioning, they may be able to replace it without any further complications.
Pros and Cons of a Coolant Temp Sensor
A coolant temp sensor is a common modification made to certain cars in order to prevent the engine from running too lean at idle. By increasing the coolant temperature, the ECU will retard the ignition timing in order to prevent detonation.
There are a few advantages and disadvantages to using a coolant temp sensor. The main advantage is that it can help prevent the engine from running too lean at idle, which can lead to increased fuel economy and improved performance. On the other hand, if your car has an unreliable or inaccurate temp sensor, it could cause problems with your car’s overall performance. Additionally, if your car’s ECU is set up for a specific type of oil (such as synthetic oil), changing to a different type of oil may result in inconsistent power and poor fuel economy.
Conclusion
There have been reports of some Honda and Acura cars running a bit lean at idle when the coolant temperature sensor is replaced. This doesn’t seem to cause any problems while driving, but it could lead to decreased fuel economy. If you’re experiencing this issue, you can check if your car has the sensor by removing the air filter and looking for a small plastic black box next to the exhaust manifold. If your car has the sensor, then you should replace it as soon as possible to avoid potential fuel economy issues down the road.