What does a knock sensor do?

User Avatar

Wiki User

βˆ™ 2013-09-26 17:40:16

Best Answer

A knock sensor assures that you're getting as much power and fuel economy as is possible from your engine.

More details:

A knock sensor allows the engine to run with the ignition timing as far advanced as possible. The computer will continue to advance the timing until the knock sensor detects pinging. At that point the computer retards the ignition timing just enough for the pinging to stop.

The knock sensor responds to spark knock caused by Pre-detonation of the Air/Fuel mixture. As the flame front moves out from the spark plug ignition point, pressure waves in the chamber crash into the piston or cylinder walls resulting in a sound known as a knock or ping. This is caused by using a fuel with a low octane rating, overheating, or over advanced timing. Sometimes it can be caused by hot carbon deposits on the piston or cylinder head that raise compression. A knock sensor is comprised of Piezoelectric materials; Crystals that when impacted, generate a voltage (same idea as a BBQ ignitor). This voltage is monitored by the computer, and when an irregularity is detected, the computer corrects timing in VVT (variable valve timing) engines, or triggers a DTC Diagnostic Trouble Code) in older vehicles.

User Avatar

Wiki User

βˆ™ 2013-09-26 17:40:16
This answer is:
User Avatar
User Avatar


Lvl 1
βˆ™ 2020-09-11 18:58:53
I had a knocking sound in my 2004 SSR and had a mechanic tell me it was a common issue with the engine type. Β At that time gas was upwards of $4 a gallon I was using regular. Fuel prices are down and I switched to a high octane. Β Problem solved!
Study guides

Where I can purchase purchase HID Fargo ID card in Dubai

See all cards
No Reviews

Add your answer:

Earn +20 pts
Q: What does a knock sensor do?
Write your answer...
Still have questions?
magnify glass
People also asked

What problems do the knock sensor indicate?

View results

Chevy Silverado 2001 1500 5.3v8 when you accelerate theres a small dieseling sound from underneath?

View results

How do you replace the knock sensor in 2001 silverado?

View results

Can you drive with a bad knocking sensor?

View results

What is the meaning of the idiom 'your picture is on the piano'?

View results