Detonation damage to cylinder head

The knock sensor is located on the engine block, cylinder head or intake manifold. This is because its function is to sense vibrations caused by engine knock or detonation. The PCM uses this signal to alter the ignition timing and prevent detonation.

The 4.3-liter's sensor is on the right cylinder head, beneath the rear of the exhaust manifold.

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Over heating or excessive carbon buildup on the heads and cylinder

Becareful, any popping means from engine needs to get diagnosed properly. If it is the popping im thinking of, then you have what is called engine detonation and it is very harmful and can destroy the engine. It is a condition caused either by a weak spark that causes buildup to create in the combustion chamber and what happens is that buildup begins to act as a ember and ignite fuel before it needs to ignite, in which creates a pop or another way to get detonation is leaky injectors excess fuel will cause irregular burn. Get your fuel system checked for adequate pressure and leak down test. Check your ignition system, which includes wires and plugs. Also, another popping noise on that style four cylinder comes from the timing chain systems. Unfortunately, there are quite a few things that can make that noise, it could even be the serpentine belt tensioner before it warms up. You need to test your system thoroughly, if it is not the fuel or ignition system, then remove the serpentine belt and see if the noise still occurs to eliminate the sound and you can also use a long screwdriver a hearing device by putting the metal side on certain areas to pinpoint area of sound. Goodluck

Replace all cylinder segments.

you have over heated the engine and the noise may be from ring failure . It may be from detonation from the fuel detonation from an extremely hot chamber. Have a compression test done to determine internal damage _--gasket and cracked head--. Have the coolant system pressure tested to check for leakage

Run fault codes and look for failed knock sensors. I would suggest that the rattling noise is detonation from a lean fuel mixture-ignition timing or faulty EGR system. Detonation is when the fuel ignites with out the use of spark and occurs early as the piston is coming up so the piston is slammed against the cylinder walls. Prolonged detonation will cause melted holes in the pistons tops and broken rings so I would advise you fix this problem as soon as possible.

here goes for a 1 Tu. this sensor detects detonation in the engine caused by a dirty piston head dirty valves and valve train. When it detects this detonation it tells the computer to ****** the timing so it does not burn a hole in the pistons, at the same tie it tells the computer this the computer adjust the fuel mixture ratio to decrease hot soak detonation which can occur after running the engine getting it hot and turning it off for 5 minutes and causing the gas to pre ignite due to the heat of the engine. This device is made of piezoelectric material which generates a voltage due to sound running threw the knock sensor, Ceramic disks wafered together and it has a preset low and high voltage low voltage is 1.0 DC VOLTS high is 4.0 volts dc WITH 5 VOLTS DC as a reference voltage for testing purposes. to see if it is working tap near the knock sensor and if it is working you will notice a variation in the running of the engine as it changes timing and fuel mix to stop detonation.

Here is an explanation of the "knock".

Abnormal combustion (Detonation)
When unburned fuel/air mixture beyond the boundary of the flame front is subjected to a combination of heat and pressure for a certain duration (beyond the delay period of the fuel used), detonation may occur. Detonation is characterized by an instantaneous, explosive ignition of at least one pocket of fuel/air mixture outside of the flame front. A local shockwave is created around each pocket and the cylinder pressure may rise sharply beyond its design limits. If detonation is allowed to persist under extreme conditions or over many engine cycles, engine parts can be damaged or destroyed. The simplest deleterious effects are typically particle wear caused by moderate knocking, which may further ensue through the engine's oil system and cause wear on other parts before being trapped by the oil filter. Severe knocking can lead to catastrophic failure in the form of physical holes punched through the piston or head (i.e., rupture of the combustion chamber), either of which depressurizes the affected cylinder and introduces large metal fragments, fuel, and combustion products into the oil system.
Detonation can be prevented by any or all of the following techniques: the use of a fuel with high octane rating, which increases the combustion temperature of the fuel and reduces the proclivity to detonate; enriching the fuel/air ratio, which adds extra fuel to the mixture and increases the cooling effect when the fuel vaporizes in the cylinder; reducing peak cylinder pressure by increasing the engine revolutions (e.g., shifting to a lower gear); decreasing the manifold pressure by reducing the throttle opening; or reducing the load on the engine. Because pressure and temperature are strongly linked, knock can also be attenuated by controlling peak combustion chamber temperatures at the engineering level by compression ratio reduction, exhaust gas recirculation, appropriate calibration of the engine's ignition timing schedule, and careful design of the engine's combustion chambers and cooling system. As an aftermarket solution, a water injection system can be employed to reduce combustion chamber peak temperatures and thus suppress detonation.

P0332 - Knock Sensor 2 Circuit Low Input (Bank 2)

This sensor signals the engine-control computer when detonation is detected, momentarily retarding ignition timing until detonation ceases.

Most computer-controlled systems use knock sensors to ****** timing when the engine is experiencing pinging or knocking.


Obviously, a faulty knock sensor produces problems that appear to be ignition-system-related. If the knock sensor system does not provide an engine detonation signal to the PCM (powertrain control module), the engine detonates, especially on acceleration.

• The first step in diagnosing the knock sensor and knock sensor module is to check all the wires and connections in the system for loose connections, corroded terminals, and damage.
• With the ignition switch on, be sure that 12 volts are being supplied through the fuse to the knock sensor module.
• A quick check of a knock sensor is to watch the ignition's timing while the engine is running and the engine block is tapped with a hammer.
  • The noise should cause a change in timing.
• The knock sensor can also be checked by tapping near the sensor and watching for an AC pulse on a DMM or lab scope.

The pinging noise that you hear is detonation occuring in one or more of the cylinders. The dealer suggested to move to a higher octane inorder to prevent this because the higher the octane the higher the prevention of Detonation.

The Probable cause of the pinging, would be that you refilled with a bad batch of gasoline. Premium should be used in this vehicle no matter what. Due to the clearances of the heads and valves in the motor. And also due to the material used to make the cylinder heads, if severe detonation occures then the valves could be damaged.