Cylinder Knock Sensors

Knock Sensors
Knock Sensors

Masterparts offers top-quality cylinder knock sensors, manufactured by trusted automotive brands.

What does the cylinder knock sensor do in a car?

The cylinder knock sensor is a small cylindrical component that’s designed to detect irregularities in the combustion of the engine. It does this by detecting engine “knocks”.

An engine knock – also called an engine detonation or ping – happens if there’s a second, spontaneous ignition within an engine cylinder (after the regular, controlled ignition from a spark plug has occurred).

The first ignition produces a flame front that moves through the cylinder. This increases the pressure and temperature of the remaining air-fuel mixture.

Sometimes, the mix gets so hot it results in a second ignition. When the flame front from the first and second ignitions collide, it causes a “knock”.

A properly functioning knock sensor detects this and alerts the car’s engine control unit (ECU). The ECU then uses the information to correct ignition timing, until secondary combustion no longer occurs.

This YouTube video gives an example of what engine knock may sound like.

How does a cylinder knock sensor work?

Most knock sensors use piezoelectric ceramics or elements.

A piezoelectric ceramic is a “smart” ferroelectric material that converts a mechanical effect (such as an engine vibration) into an electrical signal, or vice versa. This type of material is widely used in sensors.

A cylinder knock sensor uses this type of intelligent material to detect engine knocks and signal the vehicle’s computerised engine control system.

Where the knock sensor is located

In most cases, the cylinder knock sensor is connected to the outside of the engine block. However, it is also sometimes positioned under the intake manifold.

Signs of a malfunctioning cylinder knock sensor

When the cylinder knock sensor is damaged or faulty, premature self-ignition of the air-fuel mixture in engine cylinders may continue undetected.

When that happens, it can lead to increased air pressure in the cylinder and, ultimately, damage to the engine.

A number of symptoms may help indicate a faulty or damaged cylinder knock sensor:

  • loud knocking or pinging sounds from under the bonnet
  • misfiring engine
  • vibrations during acceleration
  • increased fuel consumption
  • reduced torque
  • an illuminated engine warning light.

High-quality automotive cylinder knock sensors for sale in South Africa

Masterparts offers cylinder knock sensors suitable for a very wide range of automotive makes and models. They’re designed to respond efficiently to engine knock, even at high temperatures.

Our team at Masterparts is available to help you find the best cylinder knock sensors for your vehicle.

Where to get cylinder knock sensors from Masterparts

Masterparts supplies cylinder knock sensors made by leading international manufacturers, including BREMI, Febi Bilstein and Euromann.

We offer door-to-door delivery. Alternatively, visit any of our branches across South Africa or in Windhoek, Namibia.

For cylinder knock sensors in and around Cape Town:

For cylinder knock sensors in KwaZulu-Natal:

For cylinder knock sensors in Namibia:

Masterparts supplies a massive number of automotive parts and spares, including a full range of cylinder components (along with cylinder knock sensors, including cylinder heads, sleeves/sleeve kits, pistons and piston rings and small end bushes).

Contact us if there’s a part you need and we’ll be happy to help.


Call us on 021 657 5757 or complete the form below to get a quote.

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