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Home >> Ford >> 2004 >> Excursion 6.8 S, 4WD >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Controls - Symptom Charts - CNG, Flex-Fuel & Gasoline >> Step 3: No DTC(s) Present Symptom Charts >> Chart 20

Chart 20

Engine Noise (under hood)

NOTE: Attempt to identify source of noise. If noise is from source other than those listed below, refer to STEP 2: NO DTC(S) PRESENT SYMPTOM CHART INDEX  (for noise such as spark knock) or the appropriate service information article.
SYSTEM/COMPONENT REFERENCE ( PINPOINT TEST - CNG, FLEX-FUEL & GASOLINE  ) unless noted 
Snap noise that may be due to secondary ignition arcing:
Secondary Ignition System		 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.
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