Diagnostic Procedure

STEP	INSPECTION	RESULTS	ACTION
1	VERIFY SYMPTOM Verify the occurring sound.	-	Buzzing sound is heard from exhaust pipe during cold engine start: Go to Step 2. Squeal, click, or chirp sound is heard: Go to Step 3. Rattling or creaking sound is heard: Go to Step 4. Hissing sound is heard: Go to Step 5. Clattering sound is heard: Go to Step 6. Lightly tapping or rumbling sound is heard: Go to Step 7. Other noise is heard: Go to Step 8.
2	BUZZING SOUND IS HEARD FROM EXHAUST PIPE DURING COLD ENGINE START Verify the sound from the exhaust pipe during a cold engine start. Does the sound disappear after approx. 30 s have elapsed?	Yes	NOTE: During a cold engine start, sound occurs for up to approx. 30 s with fast idle up for a drive-by-wire control and the warm-up promotion spark retard correction for ignition timing control. Go to Step 9 because the operation is normal.
2		No	Inspect the following: Exhaust system installation condition Intake system installation condition If there is any malfunction: Repair or replace the malfunctioning part according to the inspection results. If there is no malfunction: Go to Step 9.
3	VERIFY IF THERE IS SQUEAL, CLICK, OR CHIRP SOUND Inspect the following: Engine oil level Solenoid valves installation Drive belt tension Generator installation Auto tensioner bearing damaged Splash shield or under cover loose Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
3		No	Go to Step 9.
4	VERIFY IF THERE IS RUMBLE OR GRIND SOUND Inspect the following: Drive belt tension Loose parts in engine compartment Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
4		No	Go to Step 9.
5	VERIFY IF THERE IS HISS SOUND Inspect the following: Vacuum leakage Spark plug loose Intake-air system leakage Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
5		No	Go to Step 9.
6	VERIFY IF THERE IS RATTLE SOUND Inspect the location of rattle for loose parts. Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
6		No	Go to Step 9.
7	VERIFY IF THERE IS RAP OR ROAR SOUND Inspect the following: Exhaust system installation condition Intake system installation condition Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
7		No	Go to Step 9.
8	VERIFY IF THERE IS KNOCK SOUND Is knocking noise present?	Yes	Perform the symptom troubleshooting "NO. 13 KNOCKING/PINGING-ACCELERATION/CRUISE". (Refer to NO. 13 KNOCKING/PINGING-ACCELERATION/CRUISE [SKYACTIV-G 2.0] .)
8	VERIFY IF THERE IS KNOCK SOUND Is knocking noise present?	No	If noise comes from engine internal: Inspect the following: Timing chain Hydraulic lash adjuster (HLA) noise Electric variable valve timing actuator Hydraulic variable valve timing actuator Engine compression Repair or replace the malfunctioning part according to the inspection results.
9	Verify the test results. If normal, return to the diagnostic index to service any additional symptoms. (Refer to SYMPTOM DIAGNOSTIC INDEX [SKYACTIV-G 2.0] .) If the malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If the vehicle is repaired, troubleshooting is completed. If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later calibration is available. Retest.