NO.19 EXHAUST SMOKE [L5]

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 • PCM DTC is stored • Excessive or insufficient fuel pressure ― Fuel pump relay or fuel pump circuit malfunction ― Clogging fuel line ― Pressure regulator malfunction (built-in fuel pump unit) ― Fuel pump unit malfunction • CMP sensor malfunction • Ignition system malfunction • Improper engine compression • Improper fuel injection timing and amount Warning • 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 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 [L5].) (See AFTER SERVICE PRECAUTION [L5].) 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

• PCM DTC is stored

• Excessive or insufficient fuel pressure

― Fuel pump relay or fuel pump circuit malfunction

― Clogging fuel line

― Pressure regulator malfunction (built-in fuel pump unit)

― Fuel pump unit malfunction

• CMP sensor malfunction

• Ignition system malfunction

• Improper engine compression

• Improper fuel injection timing and amount

Warning

• 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 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 [L5].) (See AFTER SERVICE PRECAUTION [L5].)

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 [L5].) Is there any malfunction?	Yes	Replace the PCV valve and the oil separator as a single unit, then go to the next step. (See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [L5].)
No	Inspect the following: • Blocked oil drain passage in the cylinder head • Damaged cylinder bore • Damaged valve guide, stems or valve seals • Piston ring is not seated, seized or worn. Repair or replace the malfunctioning part according to the inspection results. • 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 the following: • Cracked or porous engine block • Cylinder head gasket leakage • Intake manifold gasket leakage If other drivability symptoms are present: • Return to the diagnostic index to service any additional symptoms.
No	Inspect for cause. Repair or replace the malfunctioning part according to the inspection results.
4	Inspect the following: • Air cleaner restriction • Collapsed or restricted intake air system • Restricted fuel return line Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results. Repeat Step 4.
No	Go to the next step.
5	Perform the PCM DTC inspection using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [L5].) Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [L5].)
No	Go to the next step.
6	Inspect the fuel line pressure. (See FUEL LINE PRESSURE INSPECTION [L5].) Is there any malfunction?	Yes	Zero or low: • Inspect the fuel pump relay and the fuel pump circuit. (See RELAY INSPECTION [L5].) • Inspect the fuel line for clogging. ― If there is a malfunction: • Repair or replace the malfunctioning part according to the inspection results. ― If there is no malfunction: • Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L5].) High: • Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L5].)
No	Go to the next step.
7	Perform the Spark Test. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [L5].) Is a strong blue spark visible at each cylinder?	Yes	Go to the next step.
No	Repair or replace the malfunctioning part according to the inspection results.
8	Inspect the CMP sensor. (See CAMSHAFT POSITION (CMP) SENSOR INSPECTION [L5].) Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results.
No	Go to the next step.
9	Measure the compression pressure for each cylinder. (See COMPRESSION INSPECTION [L5].) Are compression pressures within the specification?	Yes	Inspect the fuel injector for each cylinder. (See FUEL INJECTOR INSPECTION [L5].) Replace the suspected fuel injector. (See FUEL INJECTOR REMOVAL/INSTALLATION [L5].)
No	Inspect for the following: • Damaged valve seat • Worn valve stem and valve guide • Worn or stuck piston ring • Worn piston, piston ring or cylinder • Improper valve timing Repair or replace the malfunctioning part according to the inspection results.
10	Verify test results. • If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [L5].) • 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, reprogram the PCM if a later calibration is available. Retest.

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 [L5].)

Is there any malfunction?

Yes

Replace the PCV valve and the oil separator as a single unit, then go to the next step.

(See POSITIVE CRANKCASE VENTILATION (PCV) VALVE REMOVAL/INSTALLATION [L5].)

Inspect the following:

• Blocked oil drain passage in the cylinder head

• Damaged cylinder bore

• Damaged valve guide, stems or valve seals

• Piston ring is not seated, seized or worn.

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

• If other drivability symptoms are present:

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

Does the cooling system hold pressure?

Yes

Inspect the following:

• Cracked or porous engine block

• Cylinder head gasket leakage

• Intake manifold gasket leakage

If other drivability symptoms are present:

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

Inspect for cause.

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

Inspect the following:

• Air cleaner restriction

• Collapsed or restricted intake air system

• Restricted fuel return line

Is there any malfunction?

Yes

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

Repeat Step 4.

Go to the next step.

Perform the PCM DTC inspection using the M-MDS.

(See ON-BOARD DIAGNOSTIC TEST [L5].)

Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [L5].)

Go to the next step.

Inspect the fuel line pressure.

(See FUEL LINE PRESSURE INSPECTION [L5].)

Is there any malfunction?

Yes

Zero or low:

• Inspect the fuel pump relay and the fuel pump circuit. (See RELAY INSPECTION [L5].)

• Inspect the fuel line for clogging.

― If there is a malfunction:

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

― If there is no malfunction:

• Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L5].)

High:

• Replace the fuel pump unit. (See FUEL PUMP UNIT REMOVAL/INSTALLATION [L5].)

Go to the next step.

Perform the Spark Test.

(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [L5].)

Is a strong blue spark visible at each cylinder?

Yes

Go to the next step.

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

Inspect the CMP sensor.

(See CAMSHAFT POSITION (CMP) SENSOR INSPECTION [L5].)

Is there any malfunction?

Yes

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

Go to the next step.

Measure the compression pressure for each cylinder.

(See COMPRESSION INSPECTION [L5].)

Are compression pressures within the specification?

Yes

Inspect the fuel injector for each cylinder.

(See FUEL INJECTOR INSPECTION [L5].)

Replace the suspected fuel injector.

(See FUEL INJECTOR REMOVAL/INSTALLATION [L5].)

Inspect for the following:

• Damaged valve seat

• Worn valve stem and valve guide

• Worn or stuck piston ring

• Worn piston, piston ring or cylinder

• Improper valve timing

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

Verify test results.

• If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [L5].)

• 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, reprogram the PCM if a later calibration is available. Retest.