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Exhaust System Concerns

EXHAUST SYSTEM CONCERNS DESCRIPTION

16  
DESCRIPTION
  • Smoke
EXHAUST SYSTEM CONCERNS INSPECTION/ACTION CHART

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 next step.
For blue smoke:
Burning oil indicated.
Go to step 8.
White smoke:
Water in combustion indicated.
Go to step 7.
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 next step.
No Service as required.
Verify symptom no longer exists.
3 PERFORM PCM QUICK TEST
See PCM QUICK TEST  .
  • Are any DTCs displayed during Continuous Memory or Key ON, Engine OFF (KOEO), Engine OFF (KOEO) Self-Tests? 
Yes Check for cause.
See DIAGNOSTIC TROUBLE CODE NUMBERS  .
No Go to next step.
4 CHECK FUEL DELIVERY SYSTEM Yes Go to next step.
No If pressure is greater than 380 kPa (55 psi):
Replace fuel pump.
See FUEL PUMP MODULE .
If pressure is less than 240 kPa (35 psi):
Check fuel supply line for restriction.
5 CHECK FUEL DELIVERY SYSTEM Yes Check injector for leakage.
See TEST 10: FUEL INJECTOR INSPECTION  .
If injector leaks, service as necessary.
See FUEL INJECTORS .
If injector OK, go to next step.
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 next step.
If not OK, clean or replace spark plugs.
See IGNITION COIL-ON-PLUG AND SPARK PLUG -- 2.3L , or IGNITION COIL-ON-PLUG AND SPARK PLUG -- 3.0L .
No Check following:
High-tension leads.
See TEST 15: IGNITION SCOPE TEST  .
CKP sensor.
See CRANKSHAFT POSITION (CKP) SENSOR MALFUNCTION  .
See CAMSHAFT POSITION SENSOR (CMP) MALFUNCTION  .
7 WHITE SMOKE: CHECK BASE ENGINE/COOLING SYSTEM Yes Service as required.
No Go to next step.
8 BLUE SMOKE: CHECK PCV SYSTEM
  • Remove PCV valve and shake it.
  • Does PCV valve rattle? 
Yes Install PCV valve.
Go to next step.
No Replace PCV valve.
See POSITIVE CRANKCASE VENTILATION (PCV) VALVE -- 2.3L .
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 next step.
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  .
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 INSPECTION  .

  • Is a fault indicated? 
Yes Service as required.
No Go to next step.
11
  • Verify test results. If OK, see DIAGNOSTIC INDEX  to service any additional symptoms.