Have you ever tried continuously hitting your engine with a hammer? Chances are you haven't-unless you want to destroy the engine. Do you know that engine knocks have that same effect? If you ignore these knocks, your car will end up with damaged pistons, valves, and other engine parts. And, that's exactly what will happen if you don't have an efficient knock sensor in your vehicle.
If you're out in the market searching for a new knock sensor, this guide will help you find the correct one for your ride.
A Quick Look at the Two Types of Knock Sensor
All knock sensors operate the same way: by detecting engine knock/noise and sending signals to the car's electronic control unit (ECU) so that it can do the needed adjustment and eliminate the knock. There are generally two types of sensor design available today, as follow:
- Broadband single wire sensor. This is an older design that works through the ECU familiarizing itself with the normal range of engine noise. Whenever the ECU receives a signal indicating a value higher than the normal range, it registers a knock and performs the necessary adjustment. This sensor can accommodate a wide range of changes in the engine's noise frequency, and it is also less susceptible to electromagnetic interference while it works.
- Flat response two-wire sensor. This is a newer design that works with a predetermined range of engine frequency. Whenever engine knock is detected, the sensor sends out a voltage that is higher than the said range. The advantage with this type of sensor is that it is more accurate compared to the first type.
Both of these sensors work using a piezoelectric element that receives the vibrations from the engine, upon which it generates voltage and sends this voltage to the ECU. They differ, however, in such a way that one sensor may not be compatible with an ECU that is originally designed to work with the other type of sensor. That said, you need to be sure that you get just the correct sensor type.
Other Knock Sensor Choices Available
When selecting the correct sensor, you'll find that there are different choices available for you. You can get a single sensor, one that's already a complete assembly, or one that comes in a kit. Some sensors already come with a harness while others don't-choose the best one that will meet your needs.