NO.7 KNOCKING [MZ-CD 1.6]

7	Knocking
DESCRIPTION	• Engine knock at idle. • Engine knock at idle and glow indicator light is flashing. • Engine knock during acceleration. • Engine knock during acceleration and glow indicator light is flashing. • Noisy running, misfiring, back-firing or knocking.
POSSIBLE CAUSE	• PCM DTC is detected. • Coolant leakage • Oil leakage • Fuel leakage • Visibly damaged or worn parts • Loose or missing nuts or bolts • Electrical connector, wiring harness or component damaged • Low engine oil level. • Water in fuel • CKP sensor or pulse wheel malfunction • Fuel injector malfunction • Worn or damaged oil pump. • Fuel metering valve malfunction • Supply pump malfunction • Valve timing incorrect, timing belt or pulley/sprocket damaged. • Major mechanical engine failure. • Excessive carbon build up in cylinder head and/or bore • Incorrect or contaminated fuel in fuel tank

Knocking

DESCRIPTION

• Engine knock at idle.

• Engine knock at idle and glow indicator light is flashing.

• Engine knock during acceleration.

• Engine knock during acceleration and glow indicator light is flashing.

• Noisy running, misfiring, back-firing or knocking.

POSSIBLE CAUSE

• PCM DTC is detected.

• Coolant leakage

• Oil leakage

• Fuel leakage

• Visibly damaged or worn parts

• Loose or missing nuts or bolts

• Electrical connector, wiring harness or component damaged

• Low engine oil level.

• Water in fuel

• CKP sensor or pulse wheel malfunction

• Fuel injector malfunction

• Worn or damaged oil pump.

• Fuel metering valve malfunction

• Supply pump malfunction

• Valve timing incorrect, timing belt or pulley/sprocket damaged.

• Major mechanical engine failure.

• Excessive carbon build up in cylinder head and/or bore

• Incorrect or contaminated fuel in fuel tank

STEP	INSPECTION	RESULTS	ACTION
1	VERIFY PCM DTC • Perform the PCM DTC inspection using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [MZ-CD 1.6].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [MZ-CD 1.6].)
No	Go to the next step.
2	VISUALLY INSPECT RELATED PART CONDITION • Visually inspect the following: Mechanical: ― Coolant leaks ― Oil leaks ― Fuel system leaks ― Visibly damaged or worn parts ― Loose or missing nuts or bolts Electrical: ― Fuse(s) ― Loose or corroded connector(s) (PCM, sensor(s), switch(es)) ― Damaged or worn PCM, switch(es) and/or sensor(s) • Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results. Repeat Step 2.
No	Go to the next step.
3	INSPECT ENGINE OIL LEVEL • Inspect the engine oil level. (See ENGINE OIL LEVEL INSPECTION [MZ-CD 1.6].) • Is the engine oil level normal?	Yes	Go to the next step.
No	Add specified oil. (See ENGINE OIL REPLACEMENT [MZ-CD 1.6].)
4	DETERMINE IF MALFUNCTION CAUSE IS WATER IN FUEL OR OTHER • Perform the fuel filter water draining. • Verify the symptom. • Is the symptom solved?	Yes	Troubleshooting is completed. (Water into the fuel line.)
No	Go to the next step.
5	VISUALLY INSPECT CKP SENSOR AND PULSE WHEEL • Visually inspect the CKP sensor and teeth of the crankshaft pulley. • Is there any malfunction?	Yes	Repair or replace the malfunctioning part as necessary.
No	Go to the next step.
6	INSPECT FUEL INJECTOR • Inspect the fuel injector for each cylinder. (See FUEL INJECTOR INSPECTION [MZ-CD 1.6].) • Are fuel injectors normal?	Yes	Go to the next step.
No	Replace the suspected fuel injector. (See FUEL INJECTOR REMOVAL/INSTALLATION [MZ-CD 1.6].)
7	DETERMINE IF MALFUNCTION CAUSE IS SUPPLY PUMP/FUEL METERING VALVE OR OTHER Caution • While performing this step, always operate the vehicle in a safe and lawful manner. • When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later. • Access the following PIDs using the M-MDS: (See PCM INSPECTION [MZ-CD 1.6].) ― FRP ― FRP_DSD ― FUEL_V_DSD • Monitor the each PID while driving the vehicle. • Are all PIDs normal?	Yes	Go to the next step.
No	Inspect the fuel pressure sensor and related wiring harness. (See FUEL PRESSURE SENSOR INSPECTION [MZ-CD 1.6].) • If there is malfunction, repair or replace malfunctioning part. • If there is no malfunction, replace the supply pump. (See SUPPLY PUMP REMOVAL/INSTALLATION [MZ-CD 1.6].)
8	DETERMINE IF MALFUNCTION CAUSE IS VALVE OPERATION SYSTEM OR OTHER • Inspect the followings: ― Timing belt ― Pulley and sprocket ― Valve timing. (See TIMING BELT REMOVAL/INSTALLATION [MZ-CD 1.6].) • Are all items normal?	Yes	Go to the next step.
No	Repair or replace the malfunctioning part according to the inspection results.
9	INSPECT CYLINDER • Remove the cylinder head. • Visually inspect cylinder head and cylinder bore. (See CYLINDER HEAD GASKET REPLACEMENT [MZ-CD 1.6].) • Is there any carbon or damaged part detected?	Yes	Clean the cylinder head as necessary. Repair or replace the malfunctioning part according to the inspection results.
No	Replace the fuel. (Poor fuel quality (e.g.: include water contamination, winter/summer blend)) • Flush the fuel line as necessary.
10	Verify test results. • If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZ-CD 1.6].) • If the malfunction remains, inspect the related Service Information and perform the 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.

STEP

INSPECTION

RESULTS

ACTION

VERIFY PCM DTC

• Perform the PCM DTC inspection using the M-MDS.

(See ON-BOARD DIAGNOSTIC TEST [MZ-CD 1.6].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [MZ-CD 1.6].)

Go to the next step.

VISUALLY INSPECT RELATED PART CONDITION

• Visually inspect the following:

Mechanical:

― Coolant leaks

― Oil leaks

― Fuel system leaks

― Visibly damaged or worn parts

― Loose or missing nuts or bolts

Electrical:

― Fuse(s)

― Loose or corroded connector(s) (PCM, sensor(s), switch(es))

― Damaged or worn PCM, switch(es) and/or sensor(s)

• Is there any malfunction?

Yes

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

Repeat Step 2.

Go to the next step.

INSPECT ENGINE OIL LEVEL

• Inspect the engine oil level.

(See ENGINE OIL LEVEL INSPECTION [MZ-CD 1.6].)

• Is the engine oil level normal?

Yes

Go to the next step.

Add specified oil.

(See ENGINE OIL REPLACEMENT [MZ-CD 1.6].)

DETERMINE IF MALFUNCTION CAUSE IS WATER IN FUEL OR OTHER

• Perform the fuel filter water draining.

• Verify the symptom.

• Is the symptom solved?

Yes

Troubleshooting is completed.

(Water into the fuel line.)

Go to the next step.

VISUALLY INSPECT CKP SENSOR AND PULSE WHEEL

• Visually inspect the CKP sensor and teeth of the crankshaft pulley.

• Is there any malfunction?

Yes

Repair or replace the malfunctioning part as necessary.

Go to the next step.

INSPECT FUEL INJECTOR

• Inspect the fuel injector for each cylinder.

(See FUEL INJECTOR INSPECTION [MZ-CD 1.6].)

• Are fuel injectors normal?

Yes

Go to the next step.

Replace the suspected fuel injector.

(See FUEL INJECTOR REMOVAL/INSTALLATION [MZ-CD 1.6].)

DETERMINE IF MALFUNCTION CAUSE IS SUPPLY PUMP/FUEL METERING VALVE OR OTHER

Caution

• While performing this step, always operate the vehicle in a safe and lawful manner.

• When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later.

• Access the following PIDs using the M-MDS:

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

― FRP

― FRP_DSD

― FUEL_V_DSD

• Monitor the each PID while driving the vehicle.

• Are all PIDs normal?

Yes

Go to the next step.

Inspect the fuel pressure sensor and related wiring harness.

(See FUEL PRESSURE SENSOR INSPECTION [MZ-CD 1.6].)

• If there is malfunction, repair or replace malfunctioning part.

• If there is no malfunction, replace the supply pump.

(See SUPPLY PUMP REMOVAL/INSTALLATION [MZ-CD 1.6].)

DETERMINE IF MALFUNCTION CAUSE IS VALVE OPERATION SYSTEM OR OTHER

• Inspect the followings:

― Timing belt

― Pulley and sprocket

― Valve timing.

(See TIMING BELT REMOVAL/INSTALLATION [MZ-CD 1.6].)

• Are all items normal?

Yes

Go to the next step.

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

INSPECT CYLINDER

• Remove the cylinder head.

• Visually inspect cylinder head and cylinder bore.

(See CYLINDER HEAD GASKET REPLACEMENT [MZ-CD 1.6].)

• Is there any carbon or damaged part detected?

Yes

Clean the cylinder head as necessary.

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

Replace the fuel.

(Poor fuel quality (e.g.: include water contamination, winter/summer blend))

• Flush the fuel line as necessary.

Verify test results.

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

(See SYMPTOM DIAGNOSTIC INDEX [MZ-CD 1.6].)

• If the malfunction remains, inspect the related Service Information and perform the 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.