How To Reduce Engine Knock

How To Reduce Engine Knock

Engine knock or detonation happens when excessive heat and pressure in the combustion chamber causes the air/fuel mixture to ignite on its own. This causes a sudden rise in cylinder pressure which subjects various engine parts to severe train and creates a pinging or knocking sound. At best, it's a correctable scenario is caught early. At worst, it's causing severe engine damage that gets worse over time. Engine knock can be caused by several factors and there are several ways to prevent and correct it if caught in time. Our partners at Service King Seattle in Seattle, WA have given some great advice on possible culprits to check if you're automotively oriented. 

• Up the octane rating on your fuel. Most engines will operate fine with 87, but some engines need higher. If your vehicle is high-performance or a little older, it may need as high as 91. Try a full tank of the 91 with a container of octane booster and see if that alleviates the situation.
• Check your compression. If your compression ration is over 10.5:1, you could get knock even with the best of fuels. Adjust your compression as necessary to get it into an acceptable range for common fuel octanes.
• Check your timing. Improper timing could result in an excess of pressure in the cylinder. Dial back the timing a bit and see it that helps.
• Check your fuel/air mixture. If it's too lean, it could cause knock.
• Remove carbon residue. This may be a bit time and labor intensive, but if you've gone through the other steps, it may be your best bet.
• There may be a few other culprits such as spark plugs or improper cooling but the causes listed are the most common. Give it a try and it may save you some time and money at the local shop!

Written By: Todd Hendrickson
Source: onallcylinders.com