The national cost for a knock sensor replacement in 2023 is between $158 and $582 with an average of $254​

Save $20-$200 on your auto maintenance or repair when you book through us.

CarAdvise is a free membership discount club for car owners, like Expedia or Sam's Club. We have over 26,000 shops of the largest brands in our network, like Firestone and Pep Boys.


Lower than retail price.


We've got your back.

12k/12mo Warranty.

Auto Service Peace of mind.

14-Day Assurance.


National average cost of a a Knock Sensor Replacement
for popular vehicles:

Car Model

Avg. cost


What is a knock sensor and how does it work?

A knock sensor is a device inside your engine that detects the symptoms of pre-detonation, a condition that occurs when the mixture of air and fuel inside a combustion chamber ignites sooner than it is supposed to. Another name for predetonation is “engine knock”.

Your engine is constantly going through four distinct cycles - intake, where each piston in its turn moves downward, drawing air and fuel into the combustion chamber; compression, where the piston moves back up to compress the fuel vapor; combustion, where the spark plug ignites the compressed air and fuel, causing a rapid expansion of gas that drives the piston downward; and exhaust, where the piston moves up again, expelling the byproducts of combustion out through the exhaust system.

If the timing of the combustion cycle (also known as the “ignition” or “power” cycle) is off, the result can be poor fuel efficiency, a reduction in engine power, and even serious internal engine damage. Fortunately, when pre-detonation or pre-ignition occurs, vibrations associated with the event can be felt by the knock sensor. The sensor then communicates with the engine control module (the computer that manages engine function) that adjusts ignition timing, air/fuel mixture, and other engine factors to correct the problem.


How do I know if my vehicle needs a new knock sensor?

The most common sign of a bad knock sensor is when the check engine light comes on. Not only does the knock sensor continuously monitor the engine for signs of vibration related to pre-detonation, but the engine control module that it communicates with continuously monitors the health of the sensor itself. Other common signs of a bad knock sensor include:

Pinging noises coming from the engine

A decline in engine power and performance

Decreased fuel efficiency

This text is only for demo

There are 0 shops within 20 miles of your location.



How is a a Knock Sensor Replacement done?

Replacing a knock sensor itself is not a particularly difficult task. It is usually bolted to the engine block and can be unfastened, unplugged, and removed. The new sensor is installed in its place. Access to the component, however, can be a far more involved process on many vehicles, making knock sensor replacement tricky.

For instance, it might be necessary for a technician to remove the entire intake assembly on top of your engine to access the knock sensor. The throttle body, intake plenum, hoses, wires, and more might need to be removed. Other vehicles might need to be raised and supported in the air so that the engine can be accessed from below. The starter assembly or other components might need to be removed to get to the knock sensor.

    Other questions customers ask

    Can a car run with a bad knock sensor?
    A vehicle can usually run with a bad knock sensor, but it is certainly not recommended. The problems associated with the causes of a faulty knock sensor and those that the knock sensor is supposed to detect can lead to engine damage. For instance, pre-ignition can lead to piston damage, an expensive and time-consuming repair. If the knock sensor is bad, the condition might not be recognized in time to prevent such damage.
    Can I replace my knock sensor myself?
    It is not necessarily difficult to replace a knock sensor on some vehicles. The job can be as simple as unbolting and unplugging the device, extracting it from the engine, and installing the new component in its place. That said, the procedure to get to the knock sensor can be far more complicated, requiring other components to be removed for access. The starter, intake manifold, throttle body, or other parts might need to be removed. And your vehicle might need to be lifted and supported in the air to get to the underside of the engine.
    What causes a knock sensor to go bad?
    Several problems can cause the knock sensor to fail. Among these are worn out spark plugs, cracked spark plug or coil wires, or a bad ignition coil. If the sensor does fail, other problems can go undetected, such as engine misfire and internal damage.

    This is demo Question

    This is demo Answer

    Trusted by even more leading companies.

    We've earned a reputation as the go-to choice for quality car care, with some of the biggest names in business reaping its benefits and improving their customer's car care experience.


    Join the world's largest consumer fleet.

    Over 1.5 Million already have.

    Questions? We've got answers.

    Our digital platform is designed to make maintaining and repairing your vehicle a breeze – from conveniently scheduling services, finding shops in the area, approving work remotely or getting free expert advice so you can be confident about any decision.

    There’s nothing to pay up-front; you simply only pay for repairs or services that you approve. 

    Nope, no funny business here—just get the job done and pay for what you approve. It really is that simple.

    With our handy nationwide network of over 26,000 shops to choose from and free sign-up – you can rest assured your car is in good hands. 

    With CarAdvise, you don’t need a fleet of 100,000 cars to get an amazing deal on car services. Our discounted prices are guaranteed to beat any other retail options – so why spend more? On average customers save 15-40% when they choose us – that could mean hundreds saved in just one service job.

    Learn More

    At CarAdvise, we believe life is unpredictable and if you need to reschedule or cancel an appointment – no worries! We promise there’s never any penalty for missed appointments.

    We’ve partnered with the best in the industry such as Firestone, Pep Boys, JiffyLube, Canadian Tire, NTB, Meineke, Tire Kingdom, AAMCO, Monro, FCA dealerships and many independent shops across the country.

    Ready to join the party? Just a few clicks and you’ll be all set – create your account now. You can easily create your account here.

    Just email us at or give our friendly team a ring at (844) 923-8473 and we’ll be sure to lend you the helping hand you need.

    Please have your license plate or VIN ready.