Engine Noise

ENGINE NOISE REFERENCE CHART

18	ENGINE NOISE
DESCRIPTION	Engine noise from under hood.

DTC DETECTION CONDITION POSSIBLE COUSES CHART

STEP	INSPECTION		ACTION
1	CHECK FOR NOISE Attempt to identify/isolate the source of the noise. Possible sources of noise could include: Vacuum or exhaust system leaks Loose components Secondary ignition arcing Base engine components Intake air leaks Drive belts or related components Has the source of the noise been found?	Yes	If concern is obvious, REPAIR as required. If not, GO to the next step.
1		No	ATTEMPT to get more information about the symptom. If unable to verify symptom, see DIAGNOSTIC INDEX to REPAIR any additional symptoms.
2	CHECK FOR "SNAP" SOUND THAT MAY BE DUE TO SECONDARY IGNITION ARCING Is the noise a "snap" sound?	Yes	CHECK ignition system. See TEST 11: IGNITION SCOPE TEST .
2		No	GO to the next step.
3	CHECK FOR "SPARK KNOCK" NOISE Is the noise "spark knock"?	Yes	See KNOCKING/PINGING .
3	CHECK FOR "SPARK KNOCK" NOISE Is the noise "spark knock"?	No	See DIAGNOSTIC INDEX to REPAIR any additional symptoms.