NO.19 EXHAUST SMOKE [WITHOUT WU-TWC]


19	EXHAUST SMOKE
DESCRIPTION	Blue, black, or white smoke from the 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 Warning The following troubleshooting flow chart contains the fuel system diagnosis and repair procedures. Read the following warnings before performing the fuel system services: • 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 the "BEFORE REPAIR PROCEDURE" and "AFTER REPAIR PROCEDURE" described in this manual. (See BEFORE REPAIR PROCEDURE.) (See AFTER REPAIR PROCEDURE.) Caution • If there is foreign material on the connecting area of the quick release connector, it might damage the connector or fuel pipe. To prevent this, disconnect the connector and clean the connecting area before connecting.


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	Remove and shake the PCV valve. Does the PCV valve rattle?	Yes	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 driveability symptoms are present, return to the diagnostic index to service any additional symptoms.
2	Remove and shake the PCV valve. Does the PCV valve rattle?	No	Replace the PCV valve.
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 driveability symptoms are present, return to the diagnostic index to service any additional symptoms.
3	Does the cooling system hold pressure?	No	Inspect for cause.
4	Inspect for 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.
4		No	Service if necessary. Repeat Step 4.
5	Connect the WDS or equivalent to the DLC-2. Retrieve any continuous memory, KOEO and KOER DTCs. (See KOEO/KOER SELF-TEST.) Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC test.
5		No	No DTC is displayed: Go to the next step.
6	Install a fuel pressure gauge between the fuel pipe and the fuel distributor. Start the engine and idle it. Measure the fuel line pressure at idle. Is the fuel line pressure correct at idle? (See FUEL LINE PRESSURE INSPECTION.)	Yes	Go to the next step.
6		No	Zero or low: • Inspect the fuel pump relay and fuel pump related circuits. • Inspect for fuel leakage inside the pressure regulator. • Inspect for a clogged main fuel line. High: • Inspect the pressure regulator for cause of the high pressure. • Inspect for a clogged fuel return line. • Inspect the vacuum hose to the pressure regulator.
7	Carry out a spark test. (See Spark Test.) Is a strong blue spark visible at each cylinder?	Yes	Inspect the CMP sensor.
7		No	Repair or replace the malfunctioning part according to spark test result.
8	Verify test results. • If normal, return to the diagnostic index to service any additional symptoms. • If the malfunction remains, replace or reprogram the PCM.