Common questions

Why do you need a coolant temp sensor?

Why do you need a coolant temp sensor?

That’s why in every engine, there is a coolant temp sensor to measure the engine’s fluid temperature and make sure it is at the right level. Once the coolant temperature sensor measures the temperature, it will send a signal to the on-board control system. This system gives a signal to the computer to keep or alter how the engine is functioning.

What should coolant temp be when engine is hot?

With a good OBD2 code reader, you can also check the live data and the parameters of the CTS sensor. Check that the temperature value of the CTS is around 80-90c when the engine is hot. A lot of engine coolant temperature sensors have two wires and the sensor is controlled by Ohm.

Can a bad coolant sensor cause a car to not start?

Some cars use the engine coolant temperature sensor to control the electric cooling fans. You have two separate temperature sensors for the fans, dashboard gauge, and engine management in most cars. However, if your car has a single sensor, a bad engine coolant temperature sensor may result in your fans won’t start at all.

How does the cylinder head temperature sensor work?

Some cars use a cylinder head temperature or CHT sensor instead of, or in addition to the ECT sensor. The CHT sensor (see the photo) works the same way, but it measures the temperature of the cylinder head metal and is not immersed in coolant. This allows the CHT sensor to measure the temperature of the engine correctly even with loss of coolant.

How does coolant temperature sensor affect engine performance?

A bad engine coolant temperature sensor affects engine performance: It may cause a constant lean air/fuel mixture, causing the engine to stall or idle rough. Or it may cause a constant rich air/fuel mixture, causing an increase in emissions and fuel consumption.

What does a bad coolant temperature sensor do?

If the coolant temperature sensor goes bad it can send a false signal to the computer and throw off the fuel and timing calculations. It is not uncommon for the coolant temperature sensor to fail and send a permanently cold signal to the computer.

What are the symptoms of a bad coolant temperature sensor?

Another symptom of a problem with the coolant temperature sensor is an overheating engine. The coolant temperature sensor can also fail in a manner that causes it to send a permanently hot signal. This can cause the computer to incorrectly compensate for a lean signal, which can result in overheating, and even misfires or engine ping.

Where do I find the coolant temperature sensor?

What is a Coolant Temperature Sensor and How Does It Work? A coolant temperature sensor (CTS) (also known as an ECT sensor or ECTS (engine coolant temperature sensor) is used to measure the temperature of the coolant/antifreeze mix in the cooling system, giving an indication of how much heat the engine is giving off.

Author Image
Ruth Doyle