What is Engine Knock?
Engine knocking or pinging happens when the air-fuel combination self-ignites due to excessive heat before the spark plug ignites it. It can be brought on by a lean air-fuel mixture, low fuel octane, or incorrect ignition timing.
As the engine rises, the air-fuel mixture will self-ignite halfway up, creating a tremendous pressure because the piston has only halfway reached the top of the engine. Additionally, it can produce temperatures so high that they melt holes in your cylinder head or pistons.
This is why it is a good idea to correct your engine knock as soon as possible and to avoid using it while driving.
HOW TO FIX AN ENGINE KNOCK
Now that you are aware of the several possible causes of engine knock, you undoubtedly want to know how to remedy it.
Only mechanics enjoy the sound of an engine knocking. The majority of us will struggle to identify if the noise is a spark knock, valve lifter tap, rocker arm, or rod knock. Before it results in significant damage, car owners can take a few actions to fix engine noise.
- Oil and filter replacement
An oil change is the initial step. All of the engine’s moving parts are lubricated by oil, which also helps the engine remove metal filings and other dirt and dissipate heat. Most of the particles are removed by the oil filter, but sludge does accumulate and can recirculate into engine parts. Old, soiled oil can make parts stick, and poor grade oil can thin with engine heat and damage other parts while leaving a sticky sheen on the cylinder walls. Every 5,000 to 8,000 miles, change the oil and filter with those that the manufacturer recommends. Every 3,000 miles or every three or six months was the previous standard. Some people advocate every 10,000 miles, but that might be pushing it.
- Use fuel with high octane
Engine performance and wear might be negatively impacted by the fuel type. Low-octane fuel could be cheaper, but the engine’s efficiency and performance might decrease. Repairing engine damage could also be more expensive. Make sure you are using the fuel type recommended by the manufacturer if you are experiencing engine knock. In order to raise the octane rating and, ideally, stop the knocking, you might also add an octane booster.
- Include a fuel cleaner
The majority of vehicle fuels contain some detergent to stop carbon from building up on the spark plug electrodes and cylinder walls. Hotspots, early fuel-air detonation, and a banging sound can be brought on by carbon buildup. Additional fuel detergent may help with engine knock and carbon removal.
- Combustion chamber cleaning
Combustion chamber carbon accumulation will result in decreased volume and increased compression. The accumulation hinders combustion, reduces firing effectiveness, and shortens the power stroke. There are various tools and techniques you can use to clean the combustion chamber. View some internet videos, read the product instructions, and adhere to them. Alternately, have your dependable mechanic perform the task for you.
- Examine or change the spark plugs.
Different temperatures are rated for spark plugs, and the distance between the electrodes needs to be precise. Due to its heat tolerance, an improper spark plug might cause detonation to happen before it should, resulting in spark knock. If the spark plug gap is excessively small or large, It won’t even try to spark. The electrodes may become coated with carbon, which would close the gap. Make that the vehicle is using the recommended plugs and that the gap is properly set, then inspect and clean the spark plugs.
- Lower the Intake Charge Temperature and Density
Because it is denser and expands more when heated, cool air contributes more oxygen to the fuel-air combustion combination. A higher density engine intake charge is possible with a lower air intake temperature, which improves combustion and cuts down on burn time. Ensure that the air intake is free from obstructions and far from hot engine components, such as the exhaust manifold.
- Boost the engine’s speed
Short, slow journeys through the city prevent the engine from heating up and can result in carbon buildup. Low-octane fuel or old fuel from sitting in the drive for a long time may be the cause of low-speed knock. Make sure you’re using the proper grade of fuel and go for an hour or so on the highway to clean out the pipes.
- Swap out the knock sensor
A malfunctioning knock sensor may be to blame if you hear engine knocking. The sensor is not easily accessible, and the majority of individuals lack the tools necessary to ensure that it is functioning properly. Bring your vehicle to a reputable repair facility and have them examine it and replace it if necessary.
- Add more or less liquid to the mixture A lean mixture contains less fuel than a rich mixture, which has more fuel in the air-fuel mixture. All of the fuel in the chamber will be burned in the ideal mixture, leaving no oxygen behind. By lowering the compression temperature and minimizing the likelihood of premature detonation, a rich mix will lessen banging.
The air is thinner at higher altitudes. In the air-fuel mixture, more air must be burned in order to burn the same amount of fuel because the air is thinner. The combustion chamber will burn more thoroughly and there will be less likelihood of detonation banging with a thinner mixture.