Skip the auto shop - Our mechanics make house calls

Q: Knock Sensor issue

asked by on

I just bought a 2003 Chevy Silverado 1500 z71 4x4, 135,000 miles, 4.8L V8 with some rust, it does have a slight ruff idle and sounds like lifter knock when hot or cold, if i blip the throttle the knock go's away for a few mins, i changed the oil and spark plugs as soon as i got it home, the check engine light was on as well. i went to advanced auto and had them scan the code, it came up as knock sensor bank 2, i purchase 2 new knock sensors, wiring harness and intake gasket, installed everything and the code came back after a few days of driving it as bank 1 now, i traced the wires from the knock sensor harness and everything looks fine, i pulled them back out and replace them once again. but same thing, engine light came back after a few days. would replacing injectors or coil packs help me any?

My car has 135000 miles.
My car has an automatic transmission.

A: The sensors are doing their job and telling...

The sensors are doing their job and telling you there is a knock in the engine. Even though it may seem like the sound went away, you may not be able to hear it when you drive but the sensors can. The knock sensors are designed to produce a voltage when they hear a knock noise from the engine internal parts.

You need to have the noise you hear checked by a mechanic to see what is the cause and what needs to be done in order to fix it.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Rattle/banging in front end over bumps?

Hello, thank you for writing in. Tracing down a rattle can be frustrating. It takes a process of elimination, and tests to every part of the suspension, steering, and wheel assemblies. You are correct in wanting to test the control...

Q: Stuck thermostat?

From what you described, it potentially might be a few different things that may be wrong with your cooling system. As you may know, when the coolant is pumped through the radiator to the engine, some of this coolant is...

Q: Coolant reserve tank removal.

Hi there If you've never completed this type of repair, you should purchase a service manual for your 2003 Cadillac DeVille which will give you detailed instructions on how to correctly remove the coolant reservoir.

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.