NO.21 ENGINE NOISE [MZ-CD 1.6 (Y6)]

21	ENGINE NOISE
DESCRIPTION	• Engine noise under the hood.
POSSIBLE CAUSE	• Engine internal damage • Timing belt displacement • Fuel injector malfunction • Loose attaching bolts or worn parts • Improper drive belt tension • Air leakage from intake-air system • Incorrect injection timing • Erratic signal from CKP sensor • Erratic signal from CMP sensor • Fuel pressure sensor or related circuit malfunction • Boost sensor or related circuit malfunction • Accelerator pedal position sensor or related circuit malfunction • MAF/IAT sensor or related circuit malfunction • ECT sensor or related circuit malfunction • EGR system or malfunction • Vacuum leakage • Fuel metering valve malfunction • Air leakage from intake-air system • Air in power steering fluid line • Turbocharger operating noise • Solenoid valve operating noise Предупреждение The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before servicing the fuel system: • 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 REPAIR PROCEDURE” and “AFTER REPAIR PROCEDURE” described in this manual. Примечание • The PCM checks the fuel injection amount during a set interval while idling, and automatically corrects it to maintain engine efficiency. It is normal that engine noise and vibration might be a little louder during this process.

ENGINE NOISE

DESCRIPTION

• Engine noise under the hood.

POSSIBLE CAUSE

• Engine internal damage

• Timing belt displacement

• Fuel injector malfunction

• Loose attaching bolts or worn parts

• Improper drive belt tension

• Air leakage from intake-air system

• Incorrect injection timing

• Erratic signal from CKP sensor

• Erratic signal from CMP sensor

• Fuel pressure sensor or related circuit malfunction

• Boost sensor or related circuit malfunction

• Accelerator pedal position sensor or related circuit malfunction

• MAF/IAT sensor or related circuit malfunction

• ECT sensor or related circuit malfunction

• EGR system or malfunction

• Vacuum leakage

• Fuel metering valve malfunction

• Air leakage from intake-air system

• Air in power steering fluid line

• Turbocharger operating noise

• Solenoid valve operating noise

Предупреждение

The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before servicing the fuel system:

• 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 REPAIR PROCEDURE” and “AFTER REPAIR PROCEDURE” described in this manual.

Примечание

• The PCM checks the fuel injection amount during a set interval while idling, and automatically corrects it to maintain engine efficiency. It is normal that engine noise and vibration might be a little louder during this process.

STEP	INSPECTION	RESULTS	ACTION
1	Is squeal, click or chirp sound present?	Yes	Inspect the engine oil level, solenoid valves installation or drive belt.
No	Go to the next step.
2	Is rumble or grind sound present?	Yes	Inspect the drive belt tension or the power steering system fluid level. If normal, perform power steering fluid line air bleed.
No	Go to the next step.
3	Is rattle sound present?	Yes	Inspect the location of the rattle for loose parts.
No	Go to the next step.
4	Is hiss sound present?	Yes	Inspect for vacuum leakage and intake-air system leakage.
No	Go to the next step.
5	Is rap or roar sound present?	Yes	Inspect the exhaust system or loose parts.
No	Go to the next step.
6	Perform the self-test function using the M-MDS. Turn the engine switch to the ON position. Retrieve any DTC. Are DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC test. Communication error message is displayed: Inspect for the following: • Open circuit between PCM control relay and PCM terminal 236 or 231 • Open circuit between PCM control relay and PCM terminal 241 • PCM control relay stuck open • Open or poor ground circuit (PCM terminal 307, 308 or 332) • Poorly connected vehicle body ground
No	No DTC is displayed: Go to the appropriate DTC test.
7	Access the ECT PID. Inspect the ECT PID while warming up the engine. Is the PID value correct?	Yes	Go to the next step.
No	Inspect the ECT sensor and related wiring harnesses.
8	Access the IAT PID. Inspect the IAT PID while running engine. Is the PID value correct?	Yes	Go to the next step.
No	Inspect the IAT sensor and related wiring harnesses.
9	Visually inspect CKP sensor and teeth of pulse wheel. Are the CKP sensor and the teeth of pulse wheel normal?	Yes	Go to the next step.
No	Replace malfunctioning parts.
10	Measure gap between CKP sensor and teeth of pulse wheel. Specification 1.5—2.5 mm {0.059—0.098 in} Is the gap within specification?	Yes	Go to the next step.
No	Adjust the CKP sensor position.
11	Visually inspect CMP sensor and teeth of pulse wheel. Are the CMP sensor and the teeth of pulse wheel normal?	Yes	Inspect the following PIDs: (See PCM INSPECTION [MZ-CD 1.6 (Y6)].) • APP • ECT • IAT • MAF • MAP • RPM If the PID value is not as specified, repair or replace malfunctioning parts. If the PID value is normal, go to the next step.
No	Replace malfunctioning parts.
12	Perform the EGR system inspection. Is the EGR system normal?	Yes	Go to the next step.
No	Repair or replace malfunctioning part according to the EGR system operation results.
13	Remove parts necessary to inspect the turbocharger. Примечание • Do not remove the turbocharger. Inspect if the turbocharger compressor wheel is bent, damaged, or interfering with housing on vehicle. Is there any problem?	Yes	Replace the turbocharger.
No	Go to the next step.
14	Inspect if turbocharger compressor wheel locknut is loose or has fallen down inside turbocharger. Is there any problem?	Yes	Replace the turbocharger.
No	Go to the next step.
15	Turn the turbocharger compressor wheel by hand. Does the wheel turn easily and smoothly?	Yes	Go to the next step.
No	Replace the turbocharger.
16	Inspect if turbocharger turbine wheel is damaged, cracked or interfering with housing on vehicle. Примечание • Inspect all fins on each turbine wheel. Is there any problem?	Yes	Replace the turbocharger.
No	Go to the next step.
17	Is any engine oil found inside the turbocharger turbine housing?	Yes	Excessive amount of oil is found: Replace the turbocharger. Small amount of oil is found: Wipe oil off of the vehicle, then go to the next step.
No	Go to the next step.
18	Is any engine oil found inside the turbocharger compressor housing?	Yes	Wipe oil off of the vehicle, then go to the next step.
No	Go to the next step.
19	Is any exhaust gas leakage found around location where the turbocharger is attached to the exhaust manifold?	Yes	Remove the turbocharger. Inspect for cracks on center housing inlet surface. If cracks are found, replace the turbocharger.
No	Go to the next step.
20	Are any center housing and turbine housing attaching bolts loose?	Yes	Retighten the loose bolts. If a bolt is found to be missing, attach an appropriate new bolt.
No	The turbocharger is normal. Install all parts removed in Step 13. Go to the next step.
21	Inspect fuel metering valve. (See ПРОВЕРКА ДОЗИРУЮЩЕГО КЛАПАНА [MZ-CD 1.6 (Y6)].) Is the fuel metering valve normal?	Yes	Go to the next step.
No	Replace the fuel pump. (See СНЯТИЕ И УСТАНОВКА ТНВД [MZ-CD 1.6 (Y6)].)
22	Inspect fuel injector and fuel injector gasket. (See ПРОВЕРКА ТОПЛИВНЫХ ФОРСУНОК [MZ-CD 1.6 (Y6)].) Is the fuel injector normal?	Yes	Inspect for the following: • Metal flow • Bent connecting rod • Damaged valve seat • Incorrect valve clearance
No	Repair or replace if necessary.
23	Verify test results. • If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZ-CD 1.6 (Y6)].) • If the malfunction remains, inspect related Service 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, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZ-CD 1.6 (Y6)].)

STEP

INSPECTION

RESULTS

ACTION

Is squeal, click or chirp sound present?

Yes

Inspect the engine oil level, solenoid valves installation or drive belt.

Go to the next step.

Is rumble or grind sound present?

Yes

Inspect the drive belt tension or the power steering system fluid level.

If normal, perform power steering fluid line air bleed.

Go to the next step.

Is rattle sound present?

Yes

Inspect the location of the rattle for loose parts.

Go to the next step.

Is hiss sound present?

Yes

Inspect for vacuum leakage and intake-air system leakage.

Go to the next step.

Is rap or roar sound present?

Yes

Inspect the exhaust system or loose parts.

Go to the next step.

Perform the self-test function using the M-MDS.

Turn the engine switch to the ON position.

Retrieve any DTC.

Are DTCs displayed?

Yes

DTC is displayed:

Go to the appropriate DTC test.

Communication error message is displayed:

Inspect for the following:

• Open circuit between PCM control relay and PCM terminal 236 or 231

• Open circuit between PCM control relay and PCM terminal 241

• PCM control relay stuck open

• Open or poor ground circuit (PCM terminal 307, 308 or 332)

• Poorly connected vehicle body ground

No DTC is displayed:

Go to the appropriate DTC test.

Access the ECT PID.

Inspect the ECT PID while warming up the engine.

Is the PID value correct?

Yes

Go to the next step.

Inspect the ECT sensor and related wiring harnesses.

Access the IAT PID.

Inspect the IAT PID while running engine.

Is the PID value correct?

Yes

Go to the next step.

Inspect the IAT sensor and related wiring harnesses.

Visually inspect CKP sensor and teeth of pulse wheel.

Are the CKP sensor and the teeth of pulse wheel normal?

Yes

Go to the next step.

Replace malfunctioning parts.

Measure gap between CKP sensor and teeth of pulse wheel.

Specification

1.5—2.5 mm {0.059—0.098 in}

Is the gap within specification?

Yes

Go to the next step.

Adjust the CKP sensor position.

Visually inspect CMP sensor and teeth of pulse wheel.

Are the CMP sensor and the teeth of pulse wheel normal?

Yes

Inspect the following PIDs:

(See PCM INSPECTION [MZ-CD 1.6 (Y6)].)

• APP

• ECT

• IAT

• MAF

• MAP

• RPM

If the PID value is not as specified, repair or replace malfunctioning parts.

If the PID value is normal, go to the next step.

Replace malfunctioning parts.

Perform the EGR system inspection.

Is the EGR system normal?

Yes

Go to the next step.

Repair or replace malfunctioning part according to the EGR system operation results.

Remove parts necessary to inspect the turbocharger.

Примечание

• Do not remove the turbocharger.

Inspect if the turbocharger compressor wheel is bent, damaged, or interfering with housing on vehicle.

Is there any problem?

Yes

Replace the turbocharger.

Go to the next step.

Inspect if turbocharger compressor wheel locknut is loose or has fallen down inside turbocharger.

Is there any problem?

Yes

Replace the turbocharger.

Go to the next step.

Turn the turbocharger compressor wheel by hand.

Does the wheel turn easily and smoothly?

Yes

Go to the next step.

Replace the turbocharger.

Inspect if turbocharger turbine wheel is damaged, cracked or interfering with housing on vehicle.

Примечание

• Inspect all fins on each turbine wheel.

Is there any problem?

Yes

Replace the turbocharger.

Go to the next step.

Is any engine oil found inside the turbocharger turbine housing?

Yes

Excessive amount of oil is found:

Replace the turbocharger.

Small amount of oil is found:

Wipe oil off of the vehicle, then go to the next step.

Go to the next step.

Is any engine oil found inside the turbocharger compressor housing?

Yes

Wipe oil off of the vehicle, then go to the next step.

Go to the next step.

Is any exhaust gas leakage found around location where the turbocharger is attached to the exhaust manifold?

Yes

Remove the turbocharger.

Inspect for cracks on center housing inlet surface.

If cracks are found, replace the turbocharger.

Go to the next step.

Are any center housing and turbine housing attaching bolts loose?

Yes

Retighten the loose bolts.

If a bolt is found to be missing, attach an appropriate new bolt.

The turbocharger is normal.

Install all parts removed in Step 13.

Go to the next step.

Inspect fuel metering valve.

(See ПРОВЕРКА ДОЗИРУЮЩЕГО КЛАПАНА [MZ-CD 1.6 (Y6)].)

Is the fuel metering valve normal?

Yes

Go to the next step.

Replace the fuel pump.

(See СНЯТИЕ И УСТАНОВКА ТНВД [MZ-CD 1.6 (Y6)].)

Inspect fuel injector and fuel injector gasket.

(See ПРОВЕРКА ТОПЛИВНЫХ ФОРСУНОК [MZ-CD 1.6 (Y6)].)

Is the fuel injector normal?

Yes

Inspect for the following:

• Metal flow

• Bent connecting rod

• Damaged valve seat

• Incorrect valve clearance

Repair or replace if necessary.

Verify test results.

• If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZ-CD 1.6 (Y6)].)

• If the malfunction remains, inspect related Service 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, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZ-CD 1.6 (Y6)].)