Diagnostic Procedure

ENGINE NOISE (SKYACTIV-G) 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 the next step. Squeal, click, or chirp noise: Go to Step 3. Thumping/rattling or creaking sound noise: Go to Step 4. Hissing sound noise: Go to Step 5. Clattering noise: Go to Step 6. Lightly tapping or rumbling noise: Go to Step 7. Other noise: 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. Perform the repair completion verification 1 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 location and perform the repair completion verification 1. If there is no malfunction: Perform the repair completion verification 1.
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 location and perform the repair completion verification 1.
3		No	Perform the repair completion verification 1.
4	VERIFY IF THERE IS THUMPING/RATTLING OR CREAKING SOUND Inspect the following: Drive belt tension Loose parts in engine compartment - Loose fitting heater hoses vibrating the heater hose bracket protector Is there any malfunction?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification 1.
4		No	Perform the repair completion verification 1.
5	VERIFY IF THERE IS HISSING SOUND Inspect the following: Vacuum leakage Spark plug incorrect installation Air leakage from intake-air system Is there any malfunction?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification 1.
5		No	Perform the repair completion verification 1.
6	VERIFY IF THERE IS CLATTERING SOUND Inspect the location of rattle for loose parts. Is there any malfunction?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification 1.
6		No	Perform the repair completion verification 1.
7	VERIFY IF THERE IS LIGHTLY TAPPING OR RUMBLING SOUND Inspect the following: Exhaust system installation condition Intake system installation condition Is there any malfunction?	Yes	Repair or replace the malfunctioning location and perform the repair completion verification 1.
7		No	Perform the repair completion verification 1.
8	VERIFY IF THERE IS KNOCK SOUND Is knocking noise present?	Yes	Perform the symptom troubleshooting [KNOCKING/PINGING-ACCELERATION/CRUISE]. (See KNOCKING/PINGING-ACCELERATION/CRUISE [SKYACTIV-G] .)
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 location and perform the repair completion verification 1.
Repair completion verification 1	VERIFY THAT VEHICLE IS REPAIRED Install/connect the part removed/disconnected during the troubleshooting procedure. Has the malfunction symptom been eliminated?	Yes	Complete the symptom troubleshooting. (Explain contents of repair to customer)
Repair completion verification 1		No	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See MALFUNCTION DIAGNOSIS FLOW [CONTROLLER AREA NETWORK (CAN)] .) If the CAN communication is normal, perform the diagnosis from Step 1. If the malfunction recurs, replace the PCM. (Refer to PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.0] in service information.)