Mechanic Glossary

2 Above Knock Threshold

A fault indicating that combustion vibrations in cylinder 2 exceed safe limits.

Cylinder 2 is located near the front of the engine block. The knock sensor monitors cylinder 2 during its power stroke. If it detects high-frequency vibrations from pre-ignition, it cuts ignition timing. If the knock continues despite timing changes, this code triggers. Bad spark plugs or a lean fuel mixture are common causes.

Frequently Asked Questions

The engine computer detected pre-ignition knocking in cylinder 2 that was louder than safe limits.
A bad spark plug, a clogged fuel injector, or low-quality fuel. Carbon deposits on the piston can also cause pre-ignition.
Inspect the spark plug, run a fuel injector cleaner, or clean the carbon from the combustion chamber.

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