Chart 20

Engine Noise (under hood)

NOTE: Attempt to identify the source of the noise. If the noise is from a source other than those listed below, refer to STEP 2: NO DIAGNOSTIC TROUBLE CODES (DTCS) PRESENT SYMPTOM CHART INDEX (for noise such as spark knock) or the applicable service information article.

SYSTEM/COMPONENT	REFERENCE (Pinpoint Test unless noted)
Secondary Ignition System Snap noise that may be due to secondary ignition arcing.	For vehicles equipped with a coil pack ignition system, refer to PINPOINT TEST JC - Secondary Ignition (Coil Pack) . For all others, CHECK the condition of the spark plug boots.