Unless you’re really into the automotive side of things, the answer is probably not a lot. Owning a vehicle is no doubt convenient and it makes life a whole lot easier when you have your own mode of transport to get you from Point A to Point B. However, owning a vehicle is not all fun and games. It comes with a lot of responsibility and, sometimes, a lot of stress for the vehicle owner when they don’t understand why their vehicle is not working as it should.
Every vehicle owner should have a basic understanding about the different parts and components of their vehicle. That way, if something goes wrong, you’re able to keep a cool head on your shoulders while you try to figure out the problem. Today, we’re talking about your EGT sensors.
EGT Sensors Explained
Table of Contents
An EGT sensor in a vehicle stands for Exhaust Gas Temperature (EGT) sensor. An EGT sensor would normally be a K-Type thermocouple. The K-Type thermocouple is not the only type of sensor. EGT sensors come in several variants that are identified by their letter. For example, you could have J, S, B, or more. The different letter assignments stand for different working temperature ranges.
Different EGT sensor materials have a different level of what is an acceptable error range. For example, with Redline EGT Sensors by DPF, testing equipment is required for a NOx sensor, and the testing equipment must have the latest software update for each NOx sensor part number. Different sensor materials also have life expectancies that differ from each other. Since no two sensors are built the same, it is always best to invest in quality. Quality EGT sensors are something you never want to skimp out on when it comes to your vehicle. Compromising on quality could only lead to a much bigger bill down the road.
In the automotive world, the most common type of EGT sensor you will encounter is the K-Type thermocouple. A quick little tip for you to keep in mind is that a K-Type thermocouple does not necessarily measure temperatures. It could also be used to measure other things like coolant temperature, oil temperatures, air temperature, or anything else that you could fit your K-Type thermocouple into. Basically, if it fits, you can measure it.
A Little More About the K-Type Thermocouple
A K-Type thermocouple also acts as a temperature sensor. It is made of two dissimilar metals. There is a reason for this, and it is because in different temperature settings, the dissimilar metals will react differently to each other. When that happens, a tiny voltage is produced. When the voltage is put through an amplifier, you can produce a temperature calibration chart. This will tell you what temperature your sensor is measuring. However, this can only be done if you know the type of metals you’re working with. Your auto mechanic should be able to do this if you don’t have the right equipment for the job.
The K-Type thermocouple is usually made up of nickel alumel and nickel chromium. This will give your sensor an operating range that starts from -200 degrees Celcius all the way up to 1260 degrees Celsius. This sensor is the most recommended type when it comes to EGT sensors because they are extremely reliable and very accurate. A well built K-Type thermocouple will have a working temperature range of 1100 degrees Celsius.
Now the K-Type thermocouple also comes in a variety of shapes, but the one that you need to use to measure your EGT should be about a quarter of an inch thick. It should also have an open tip. These sensors also come in an eighth inch open tip variant or a closed tip sensor. The sensor that you need for your vehicle is going to depend on the application. The most common type for an EGT sensor would be the one that is a quarter of an inch thick.
An open tip sensor would be the preferred choice because of the faster response time. An open tip sensor is able to detect a change in temperature within 200 milliseconds while a closed tip sensor will react to temperature changes only around 800 milliseconds. The latter is much slower, especially if you’re looking for a sensor that is going to detect rapid changes in temperature. The faster the temperature change detection, the better, especially when you’re dealing with something like a rapid misfire.
Where Your EGT Is Located?
On a typical six cylinder engine, you will find your EGT sensors have been located at a certain distance from the cylinder head. On a six cylinder engine, there should be six EGT sensors fitted along the six exhaust ports. The EGTs should be mounted at a certain distance from the cylinder head and it is important that all six EGT sensors are mounted at equal distance. This will ensure that all the sensors get an equal flow and accurately measure the exhaust gas temperatures.
Why Do You Need an EGT Sensor?
Now that you know roughly what an EGT sensor is and where it is located in your engine, the next question is: Why do we need these EGT sensors? Well, for starters, your engine is an air pump. When you put fuel into your engine and the fuel and the air mix together, the spark plug will cause a small explosion that starts your engine.
Your EGT sensor works to tell you that all your cylinders are working perfectly. Every cylinder should be working and performing equally without anything lagging behind. If one is lagging behind your EGT sensor is going to let you know and that is one of the reasons why we need it in our vehicles.
The EGT works by measuring the temperature that is coming out of each individual cylinder. If one cylinder has a different temperature reading compared to the others, your auto mechanic will know that the lagging cylinder is the one that needs to be checked out.
