Exhaust System Concerns

DETECTION CONDITION AND POSSIBLE CAUSE

16
DESCRIPTION	Smoke

EXHAUST SYSTEM CONCERNS INSPECTION

STEP	INSPECTION		ACTION
1	IDENTIFY EXHAUST SMOKE COLOR Identify the color of the exhaust smoke. Is the exhaust smoke either black, blue or white?	Yes	For black smoke: Rich fuel mixture indicated. Go to step 2. For blue smoke: Burning oil indicated. Go to step 8. White smoke: Water in combustion indicated. Go to step 7.
1		No	Attempt to verify symptom and exhaust smoke color.
2	BLACK SMOKE: PRELIMINARY CHECKS Perform the following preliminary checks: Air cleaner (restricted airflow). Air tube (collapsed, restricted). Fuel return lines (restricted). Are all checks OK?	Yes	Go to step 3.
2		No	Service as required. Verify symptom no longer exists.
3	PERFORM PCM QUICK TEST Are any DTCs displayed during Continuous Memory or Key ON, Engine OFF (KOEO) Self Tests?	Yes	Check for cause. See DIAGNOSTIC TROUBLE CODE NUMBERS .
3		No	Go to step 4.
4	CHECK FUEL DELIVERY SYSTEM Perform fuel pressure INSPECTION, See TEST 11: FUEL LINE PRESSURE / FUEL PRESSURE HOLD INSPECTION Fuel line pressure: 386-496 kPa (56-72 psi), 3.0L flexible fuel 380-517 kPa (55-75 psi) Is fuel pressure correct?	Yes	Go to step 5.
4		No	If pressure is greater than 496 kPa (72 psi), 3.0L flexible fuel 517 kPa (75 psi): Replace fuel pump, See FUEL PUMP in REMOVAL, OVERHAUL, AND INSTALLATION article in Engine Performance . If pressure is less than 386 kPa (56 psi), 3.0L flexible fuel 380 kPa (55 psi): Check fuel supply line for restriction.
5	CHECK FUEL DELIVERY SYSTEM Check fuel pump fuel flow, See TEST 5: FUEL DELIVERY SYSTEM Did fuel system flow the required amount of fuel?	Yes	Check injector for leakage. See TEST 12: FUEL INJECTOR INSPECTION . If injector leaks, service as necessary. See FUEL RAILS & INJECTORS in REMOVAL, OVERHAUL, & INSTALLATION article in Engine Performance . If injector OK, go to step 6.
5		No	Check fuel supply line for restriction.
6	CHECK SECONDARY IGNITION SYSTEM Is strong blue spark visible at each disconnected high-tension lead while cranking engine?	Yes	Check spark plugs: If OK, go to step 7. If not OK, clean or replace spark plugs,
6		No	Check following: High-tension leads. TEST 17: IGNITION SCOPE TEST . CKP sensor, TEST 8: CRANKSHAFT POSITION (CKP) SENSOR . CMP sensor. See CAMSHAFT POSITION (CMP) SENSOR MALFUNCTION .
7	WHITE SMOKE: CHECK BASE ENGINE/COOLING SYSTEM Check for base engine concerns (such cylinder head gasket leaks, intake manifold gasket leaks, engine block cracked or porous), See ENGINE COMPONENT TESTS . Also, check for loss of coolant. See ENGINE COOLING SYMPTOM CHART . Is a fault indicated?	Yes	Service as required.
7		No	Go to step 8.
8	BLUE SMOKE: CHECK PCV SYSTEM Remove PCV valve and shake it. Does PCV valve rattle?	Yes	Install PCV valve. Go to step 9.
8		No	Replace PCV valve.
9	CHECK BASE ENGINE Start engine and bring to normal operating temperature. Disconnect crankcase ventilation hose from throttle body. Place a stiff piece of paper over the hose. Wait one minute. Does vacuum hold paper in place?	Yes	Go to step 10.
9		No	Disconnect evaporative hose. Place a stiff piece of paper over the hose. Wait one minute. Does vacuum hold paper in place? If yes, See EVAPORATIVE EMISSION (EVAP) MONITOR AND SYSTEM MALFUNCTION step 9. If no, check for vacuum leaks, obstructions in the PCV system, oil cap, PCV valve, valve cover bolt torque/gasket leak. Service as required.
10	CHECK BASE ENGINE Check for base engine concerns (such as damaged valve guides, valve stems, valve seals, blocked oil drain passages in the heads (blue smoke on start-up) piston rings (not seated, seized, worn) damaged cylinder bores). See ENGINE COMPONENT TESTS Is a fault indicated?	Yes	Service as required.
10		No	Go to step 11.
11	Verify test results. If OK, See DIAGNOSTIC INDEX to service any additional symptoms