Knocking / Pinging

PINPOINT TEST 10 KNOCKING / PINGING DESCRIPTION

PINPOINT TEST 10	KNOCKING / PINGING
DESCRIPTION	Sound produced when air/fuel mixture is ignited by something other than spark plug

PINPOINT TEST 10 KNOCKING / PINGING INSPECTION & ACTION

PINPOINT TEST 10		KNOCKING / PINGING
STEP	INSPECTION		ACTION
1	PRELIMINARY CHECKS Perform the following preliminary checks: Vacuum lines Fuel (concerns such as fuel quality and proper grade) Intake air system Are all checks OK?	Yes	Go to next step.
1		No	Service as required. Verify symptom no longer exists.
2	CHECK IF ENGINE IS OVERHEATING NOTE: With the engine running and temperature stabilized, the ECT PID should be greater than 0.30 volt (temperature less than 116°C/241°F). Does the engine appear to be overheating?	Yes	Engine is overheating. See SYMPTOM TROUBLESHOOTING CHART - ENGINE COOLING .
2		No	Go to next step.
3	PERFORM PCM QUICK TEST Perform PCM quick test. See PCM QUICK TEST . Are any DTCs displayed during continuous memory, key on engine off (KOEO) or key on engine running (KOER) self-tests?	Yes	Check for cause. See DIAGNOSTIC TROUBLE CODE (DTC) INDEX - POWERTRAIN CONTROL MODULE (PCM) .
3		No	Go to next step.
4	CHECK BASE ENGINE Check for base engine concerns (such as improper compression, worn camshaft/valve train, gasket leaks). See SYMPTOM TROUBLESHOOTING CHART - ENGINE MECHANICAL Is a fault indicated?	Yes	Service as required.
4		No	Go to next step.
5	CHECK FUEL DELIVERY SYSTEM Perform fuel pressure inspection. See PINPOINT TEST 10: FUEL LINE PRESSURE/FUEL PRESSURE HOLD INSPECTION Fuel line pressure: 207-448 kPa (30-71 psi) for 3.0L or 4.0L 240-380 kPa (35-55 psi) for 2.3L Is fuel pressure correct?	Yes	Go to next step.
5		No	If pressure is greater than 448 kPa (71 psi) for 3.0L, 4.0L or 380 kPa (55 psi) for 2.3L: Replace fuel pump. See FUEL PUMP REMOVAL / INSTALLATION . If pressure is less than 207 kPa (30 psi) for 3.0L, 4.0L or 240 kPa (35 psi) for 2.3L: Check fuel supply line for restriction.
6	CHECK FUEL DELIVERY SYSTEM Check fuel pump fuel flow. See GENERAL PINPOINT TEST 5: FUEL DELIVERY SYSTEM . Does fuel system flow the required amount of fuel?	Yes	Check injector for leakage. See GENERAL PINPOINT TEST 11: FUEL INJECTOR INSPECTION If injector leaks, service as necessary. If injector OK, go to next step.
6		No	Check fuel supply line for restriction.
7	CHECK SECONDARY IGNITION SYSTEM Remove the fuel pump fuse. 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 SPARK PLUG REMOVAL / INSTALLATION
7		No	Check following: High-tension leads CKP sensor See CRANKSHAFT POSITION (CKP) SENSOR MALFUNCTION . CMP sensor See CAMSHAFT POSITION (CMP) SENSOR MALFUNCTION
8	CHECK POSITIVE CRANKCASE VENTILATION (PCV) SYSTEM Remove PCV valve and shake it. Does PCV valve rattle?	Yes	Install PCV valve. Go to next step.
8		No	Replace PCV valve. See PCV VALVE REMOVAL / INSTALLATION - 2.3L
9	CHECK PCV SYSTEM Start engine and bring to normal operating temperature. Disconnect crankcase ventilation hose from throttle body. Place a stiff piece of paper over the hose and wait one minute. Does vacuum hold paper in place?	Yes	Go to next step.
9		No	Disconnect evaporative hose. Place a stiff piece of paper over the hose and 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, rocker cover bolt torque/gasket leak. Service as required.
10	ADDITIONAL CHECKS Additional checks: Ignition base timing Intake air system Engine oil quality Are all checks OK?	Yes	Go to next step.
10		No	Service as required. Verify symptom no longer exists.
11	VERIFY TEST RESULTS Are test results OK?	Yes	Troubleshooting is complete.
11	VERIFY TEST RESULTS Are test results OK?	No	Service any additional symptoms. See SYMPTOM TROUBLESHOOTING CHART - ENGINE DRIVEABILITY .