21

ENGINE NOISE

DESCRIPTION

• Engine noise from under hood.

POSSIBLE CAUSE

Squeal, click or chirp noise:

• Improper engine oil level

• Loose installation of solenoid valves

• Improper drive belt tension

• Generator installation

• Auto tensioner bearing malfunction

• Splash shield or under cover loose (water splashes on drive belt)

Rumble or grinding sound noise:

• Improper drive belt tension

• Loose parts

Hiss sound noise:

• Vacuum leakage

• Loose spark plug

• Air leakage from the intake-air system

Rattle noise:

• Loose parts

Rap or roar noise:

• Dynamic damper loose

• Exhaust system loose

• Intake-air system loose

Other noise:

• Electric variable valve timing actuator malfunction

• Hydraulic variable valve timing actuator malfunction

• Timing chain noise

• Tappet noise

WARNING:

• Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel.

• Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injury or death and damage. Fuel can also irritate skin and eyes. To prevent this, always complete “BEFORE SERVICE PRECAUTION” and “AFTER SERVICE PRECAUTION” described in this manual. (See BEFORE SERVICE PRECAUTION [SKYACTIV-G 2.5].) (See AFTER SERVICE PRECAUTION [SKYACTIV-G 2.5].)

CAUTION:

• Disconnecting/connecting the quick release connector without cleaning it may possibly cause damage to the fuel pipe and quick release connector. Always clean the quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign matter.

STEP

INSPECTION

RESULTS

ACTION

1

• Is squeal, click or chirp sound present?

Yes

Inspect the following:

• Engine oil level

• Solenoid valves installation

• Drive belt tension

• Generator installation

• Auto tensioner bearing damaged

• Splash shield or under cover loose

Repair or replace the malfunctioning part according to the inspection results.

No

Go to the next step.

2

• Is rumble or grinding sound present?

Yes

Inspect the following:

• Drive belt tension

• Loose parts in engine compartment

If there is any malfunction:

• Repair or replace the malfunctioning part according to the inspection results.

No

Go to the next step.

3

• Is rattle sound present?

Yes

Inspect the location of rattle for loose parts.

Repair or replace the malfunctioning part according to the inspection results.

No

Go to the next step.

4

• Is hiss sound present?

Yes

Inspect the following:

• Vacuum leakage

• Spark plug loose

• Intake-air system leakage

Repair or replace the malfunctioning part according to the inspection results.

No

Go to the next step.

5

• Is rap or roar sound present?

Yes

Inspect the following:

• Exhaust system installation

• Intake-air system installation

• Dynamic damper installation

Repair or replace the malfunctioning part according to the inspection results.

No

Go to the next step.

6

• Is knocking noise present?

Yes

Perform the symptom troubleshooting “NO.13 KNOCKING/PINGING-ACCELERATION/CRUISE”.

(See NO.13 KNOCKING/PINGING-ACCELERATION/CRUISE [SKYACTIV-G 2.5].)

No

If noise comes from engine internal:

• Inspect the following:

• Timing chain

• Tappet noise

• Electric variable valve timing actuator

• Hydraulic variable valve timing actuator

• Engine compression

• Repair or replace the malfunctioning part according to the inspection results.

7

Verify the test results.

• If normal, return to the diagnostic index to service any additional symptoms.

  (See SYMPTOM DIAGNOSTIC INDEX [SKYACTIV-G 2.5].)

• 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.