Posts Tagged: detonation
Knock Sensor Symptoms Every Driver Should Understand
The Most Common Knock Sensor Symptoms Quick Summary Knock sensor symptoms still show up in predictable ways, such as reduced power, poor fuel economy, and stored trouble codes. Understanding what causes knock, how the sensor works, and how the ECU tests it is key to diagnosing the problem correctly, rather than blindly replacing parts. Article Knock Sensor Symptoms: What Your Engine Is Trying to Tell You I’ve diagnosed countless drivability complaints over the years, and knock sensor symptoms are some of the most misunderstood. Many people assume the engine is … Read More
Pre-ignition and detonation (knock) — What’s the difference?
There’s a difference between pre-ignition versus detonation (knock) Many car “experts” use the terms pre-ignition and detonation interchangeably or blame pre-ignition on low octane fuel. Let’s set the record straight; pre-ignition and detonation are not the same, they occur in different phases of the four-stroke process and only one is caused by using low octane fuel. What is pre-ignition? Pre-ignition is defined as starting the combustion process BEFORE the spark plug fires. It occurs during the compression stroke. Pre-ignition is caused when a hot object/area in the combustion chamber ignites … Read More
Understanding Detonation Piston Damage
Avoiding Piston Damage: The Truth About Detonation Many people confuse the terms detonation and pre-ignition. Both can cause engine damage, but the root cause is different. Preignition, as the name implies, is a combustion event that occurs before the ignition system provides a spark. The combustion can start from a hot spot within the combustion chamber or from the high heat created in a high-compression engine using low-octane fuel. Detonation, on the other hand, happens AFTER the spark has fired, combustion has started, and the piston is about 2/3 of … Read More