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 NO DIAGNOSTIC TROUBLE CODES (DTCS) PRESENT SYMPTOM CHART INDEX (for noise such as spark knock) or the appropriate Service Information article to continue diagnosis.

SYSTEM/COMPONENT	REFERENCE ( PINPOINT TESTS unless noted)
Secondary Ignition System Snap noise that may be due to secondary ignition arcing.	For vehicles equipped with a coil pack ignition system, GO to PINPOINT TEST JC . For all others, CHECK the condition of the spark plug boots.
Turbocharger System	REFER to the appropriate Fuel Charging and Controls article - Turbocharger to diagnose the turbocharger noise.