NO.19 EXHAUST SMOKE [MZR 2.0, MZR 2.5]

19	EXHAUST SMOKE
DESCRIPTION	• Blue, black, or white smoke from exhaust system.
POSSIBLE CAUSE	Blue smoke (Burning oil): • PCV valve malfunction • Engine internal oil leakage White smoke (Water in combustion): • Cooling system malfunction (coolant loss) • Engine internal coolant leakage Black smoke (Rich fuel mixture): • Air cleaner restriction • Intake air system is collapsed or restricted • Fuel return line is restricted • Excessive fuel pressure • Improper engine compression • Injector fuel leakage • Ignition system malfunction • PCM malfunction Warning The following troubleshooting flow chart contains fuel system diagnosis and repair procedures. Read following warnings before servicing 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 injuries 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 [MZR 2.0, MZR 2.5].) (See AFTER SERVICE PRECAUTION [MZR 2.0, MZR 2.5].) Caution • Disconnecting/connecting the quick release connector without cleaning it may cause damage to the fuel pipe and the quick release connector. Always clean the quick release connector joint area before disconnecting/connecting, and make sure that it is free of foreign material.

EXHAUST SMOKE

DESCRIPTION

• Blue, black, or white smoke from exhaust system.

POSSIBLE CAUSE

Blue smoke (Burning oil):

• PCV valve malfunction

• Engine internal oil leakage

White smoke (Water in combustion):

• Cooling system malfunction (coolant loss)

• Engine internal coolant leakage

Black smoke (Rich fuel mixture):

• Air cleaner restriction

• Intake air system is collapsed or restricted

• Fuel return line is restricted

• Excessive fuel pressure

• Improper engine compression

• Injector fuel leakage

• Ignition system malfunction

• PCM malfunction

Warning

The following troubleshooting flow chart contains fuel system diagnosis and repair procedures. Read following warnings before servicing 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 injuries 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 [MZR 2.0, MZR 2.5].) (See AFTER SERVICE PRECAUTION [MZR 2.0, MZR 2.5].)

Caution

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

STEP	INSPECTION	RESULTS	ACTION
1	What color is the smoke coming from the exhaust system?	Blue	Burning oil is indicated. • Go to the next step.
White	Water in the combustion is indicated. • Go to Step 3.
Black	Rich fuel mixture is indicated. • Go to Step 4.
2	Inspect the PCV valve. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION [MZR 2.0, MZR 2.5].) Is there any malfunction?	Yes	Replace the PCV valve and oil separator as a single unit. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [MZR 2.0, MZR 2.5].)
No	Inspect for the following: • Damaged valve guide, stems or valve seals • Blocked oil drain passage in the cylinder head • Piston ring is not seated, seized or worn. • Damaged cylinder bore If other drivability symptoms are present: • Return to the diagnostic index to service any additional symptoms.
3	Does the cooling system hold pressure?	Yes	Inspect for the following: • Cylinder head gasket leakage • Intake manifold gasket leakage • Cracked or porous engine block If other drivability symptoms are present: • Return to the diagnostic index to service any additional symptoms.
No	Inspect for cause.
4	Inspect the following: • Air cleaner restriction • Collapsed or restricted intake air system • Restricted fuel return line Are all items normal?	Yes	Go to the next step.
No	Repair or replace the malfunctioning part according to the inspection results. Repeat Step 4.
5	Retrieve any DTCs. (See ON-BOARD DIAGNOSTIC TEST [MZR 2.0, MZR 2.5].) Are any DTCs present?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE [MZR 2.0, MZR 2.5].)
No	Go to the next step.
6	Inspect the fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [MZR 2.0, MZR 2.5].) Is the fuel line pressure correct?	Yes	Go to the next step.
No	Low: • Inspect the fuel line for clogging. ― If there is no malfunction: • Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.0, MZR 2.5].) High: • Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.0, MZR 2.5].)
7	Perform the Spark Test. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.0, MZR 2.5].) Is a strong blue spark visible at each cylinder?	Yes	Inspect the CMP sensor. (See CAMSHAFT POSITION (CMP) SENSOR INSPECTION [MZR 2.0, MZR 2.5].)
No	Repair or replace the malfunctioning part according to the inspection results.
8	• Verify the test results. ― If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.0, MZR 2.5].) ― If the malfunction remains, inspect the 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 [MZR 2.0, MZR 2.5].)

STEP

INSPECTION

RESULTS

ACTION

What color is the smoke coming from the exhaust system?

Blue

Burning oil is indicated.

• Go to the next step.

White

Water in the combustion is indicated.

• Go to Step 3.

Black

Rich fuel mixture is indicated.

• Go to Step 4.

Inspect the PCV valve.

(See POSITIVE CRANKCASE VENTILATION (PCV) VALVE INSPECTION [MZR 2.0, MZR 2.5].)

Is there any malfunction?

Yes

Replace the PCV valve and oil separator as a single unit.

(See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [MZR 2.0, MZR 2.5].)

Inspect for the following:

• Damaged valve guide, stems or valve seals

• Blocked oil drain passage in the cylinder head

• Piston ring is not seated, seized or worn.

• Damaged cylinder bore

If other drivability symptoms are present:

• Return to the diagnostic index to service any additional symptoms.

Does the cooling system hold pressure?

Yes

Inspect for the following:

• Cylinder head gasket leakage

• Intake manifold gasket leakage

• Cracked or porous engine block

If other drivability symptoms are present:

• Return to the diagnostic index to service any additional symptoms.

Inspect for cause.

Inspect the following:

• Air cleaner restriction

• Collapsed or restricted intake air system

• Restricted fuel return line

Are all items normal?

Yes

Go to the next step.

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

Repeat Step 4.

Retrieve any DTCs.

(See ON-BOARD DIAGNOSTIC TEST [MZR 2.0, MZR 2.5].)

Are any DTCs present?

Yes

Go to the appropriate DTC inspection.

(See DTC TABLE [MZR 2.0, MZR 2.5].)

Go to the next step.

Inspect the fuel line pressure.

(See FUEL LINE PRESSURE INSPECTION [MZR 2.0, MZR 2.5].)

Is the fuel line pressure correct?

Yes

Go to the next step.

Low:

• Inspect the fuel line for clogging.

― If there is no malfunction:

• Replace the fuel pump unit.

(See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.0, MZR 2.5].)

High:

• Replace the fuel pump unit.

(See FUEL PUMP UNIT REMOVAL/INSTALLATION [MZR 2.0, MZR 2.5].)

Perform the Spark Test.

(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.0, MZR 2.5].)

Is a strong blue spark visible at each cylinder?

Yes

Inspect the CMP sensor.

(See CAMSHAFT POSITION (CMP) SENSOR INSPECTION [MZR 2.0, MZR 2.5].)

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

• Verify the test results.

― If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.0, MZR 2.5].)

― If the malfunction remains, inspect the 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 [MZR 2.0, MZR 2.5].)