Cylinder 7 is located near the rear of V8 engine blocks. Rear cylinders run hotter because they are furthest from the radiator. This thermal load makes cylinder 7 prone to pre-ignition. When the computer detects knock in cylinder 7, it retards the ignition timing. If the knocking continues, it sets this fault code to warn the driver.
Mechanic Glossary
7 Above Knock Threshold
A fault indicating that combustion vibrations in cylinder 7 exceed safe limits.
Frequently Asked Questions
The engine computer detected pre-ignition knocking in cylinder 7 that exceeded the safe operating noise limit.
Carbon buildup on the piston, a lean air-fuel ratio in cylinder 7, a bad spark plug, or low-octane fuel.
Swap the spark plug and coil pack, run a carbon clean, or inspect the fuel injector for blockages.