3.VISUAL AND PHYSICAL INSPECTION
Perform a visual and physical inspection of the entire Evaporative Emission system.
Check for the follow conditions:
- Holes or cracks
- Loose seal points
- Evidence of damaged components
- Incorrect routing of hoses and tubes
- Fuel Cap gasket seal
Were any of the above conditions found?
Ye s>>
Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 4
4.VERIFY EVAPORATIVE EMISSION LEAK
To continue testing you will need Miller Tool #8404A Evaporative EmissionLeak Detector (EELD).
WARNING: Keep lit cigarettes, sparks, flames, and other ignition sourcesaway from the test area to prevent
the ignition of explosive gases. Keep the test area well ventilated.
NOTE: The fuel tank should have between 20% and 80% of fuel tank capacity to properly test the Evap
system.
Connect the red power lead of the EELD to the battery positive terminal and the black ground lead to battery neg-
ative terminal.
Block the vent hose of the canister if using the service port.
Connect shop air to the EELD.
Set the smoke/air control switch to AIR.
Insert the tester’s AIR supply tip (clear hose) into the appropriate calibration orifice on the tester’s control panel
(based on DTC leak size).
Press the remote smoke/air start button.
Position the red flag on the air flow meter so it is aligned with the indicatorball.
When the calibration is complete, release the remote button. The EELD flowmeter is now calibrated in liters per
minute to the size leak indicated by the DTC set in the PCM.
Install the service port adapter #8404-14 on the vehicle’s service port and block the vent hose of the EVAP Canister
(if equipped) or install the #8404-ADP service adaptor into the filter line.
Connect the Air supply hose from the EELD to the service port (if equipped) or to the #8404-ADP adapter.
Press the remote button to activate AIR flow.
NOTE: Larger volume fuel tanks, lower fuel levels or if the vehicle is equipped with a Flow Management
Valve may indicate high flow and will require 4 to 5 minutes to fill.
Compare the flow meter indicator ball reading to the red flag.
ABOVE the red flag indicates a leak present.
BELOW the red flag indicates a sealed system.
Is the indicator ball above the red flag?
Ye s>>
Go To 5
No>>
Refer to the Freeze Frame data recorded in Step 1. If the data indicates thatthe vehicle was in motion
when the DTC was set, verify that all hoses are properly connected. Test Complete.
5.EVAPORATIVE EMISSION LEAK DETECTION
NOTE: A thorough visual inspection of the Evap system hoses, tubes, and connections may save time in
your diagnosis. Look for any physical damage or signs of wetness at connections. The strong smell of fuel
vapors may also aid diagnosis.
To continue testing, you will need Miller Tool #8404A Evaporative Emissions Leak Detector (EELD).
Remove the Air supply hose from the service port (if equipped) or from the #8404-ADP adapter.
Connect the SMOKE supply tip (black hose) to the service port (if equipped)or to the #8404-ADP adapter.
Set the smoke/air control switch to SMOKE.
NOTE: The flow meter indicator ball will not move in the smoke mode.
Press the remote smoke/air start button.
NOTE: Make sure that smoke has filled the EVAP system by continuing to presstheremotesmoke/airstart
button, remove the vehicle fuel cap, and wait for the smoke to exit. Once smoke is indicated reinstall the
fuel cap.
NOTE: For optimal performance, introduce smoke into the system for an additional 60 seconds; continue
introducing smoke at 15 second intervals, as necessary.
While still holding the remote smoke/air start button, use the white light(#8404-CLL) to follow the EVAP system
path, and look for the source of the leak indicated by exiting smoke.
If a leak is concealed from view (i.e., top of fuel tank), release the remotesmoke/air start button, and use the ultra-
violet (UV) black light #8404-UVL and the yellow goggles 8404-20 to look for residual traces of dye that is left
behind by the smoke.
The exiting smoke deposits a residual fluid that is either bright green or bright yellow in color when viewed with a
UV light.
NOTE: The EVAP System is divided into three zones. A leak from any of these zonescancausethisDTCto
set. The lists below specify the possible leak points in that specific zone. For further assistance see the
Zone Identification Charts below.
ZONE 1
1FuelCap
2 Recirculation Check Valve.
3 Vapor Recirculation Line.
4 Signal Vapor Line for FVM.
5 Flow Management Valve.
6 Fuel Tank to Canister Vapor Line connection.
7 Fuel Tank Vent (Check Valve).
8 Vapor Line to Canister.
9 Flow Control Orfice.
10 Control Valve.
11 Liquid Trap.
12 Fuel Tank.
13 Check valve.
14 Fuel Fill Tube to Tank connector.
15 Fuel Fill Tube
Damaged or disconnected EVAP system components.
ZONE 2
1Filter.
2LDP.
3 Canister Vent Line.
4EvapCanister.
5 Chassis Purge Valve.
3.VISUAL AND PHYSICAL INSPECTION
Perform a visual and physical inspection of the entire Evaporative Emission system.
Check for the follow conditions:
- Holes or cracks
- Loose seal points
- Evidence of damaged components
- Incorrect routing of hoses and tubes
- Fuel Cap gasket seal
Were any of the above conditions found?
Ye s>>
Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 4
4.VERIFY EVAPORATIVE EMISSION LEAK
To continue testing you will need Miller Tool #8404A Evaporative EmissionLeak Detector (EELD).
WARNING: Keep lit cigarettes, sparks, flames, and other ignition sourcesaway from the test area to prevent
the ignition of explosive gases. Keep the test area well ventilated.
NOTE: The fuel tank should have between 20% and 80% of fuel tank capacity to properly test the Evap
system.
Connect the red power lead of the EELD to the battery positive terminal and the black ground lead to battery neg-
ative terminal.
Block the vent hose of the canister if using the service port.
Connect shop air to the EELD.
Set the smoke/air control switch to AIR.
Insert the tester’s AIR supply tip (clear hose) into the appropriate calibration orifice on the tester’s control panel
(based on DTC leak size).
Press the remote smoke/air start button.
Position the red flag on the air flow meter so it is aligned with the indicatorball.
When the calibration is complete, release the remote button. The EELD flowmeter is now calibrated in liters per
minute to the size leak indicated by the DTC set in the PCM.
Install the service port adapter #8404-14 on the vehicle’s service port and block the vent hose of the EVAP Canister
(if equipped) or install the #8404-ADP service adaptor into the filter line.
Connect the Air supply hose from the EELD to the service port (if equipped) or to the #8404-ADP adapter.
Press the remote button to activate AIR flow.
NOTE: Larger volume fuel tanks, lower fuel levels or if the vehicle is equipped with a Flow Management
Valve may indicate high flow and will require 4 to 5 minutes to fill.
Compare the flow meter indicator ball reading to the red flag.
ABOVE the red flag indicates a leak present.
BELOW the red flag indicates a sealed system.
Is the indicator ball above the red flag?
Ye s>>
Go To 5
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
5.EVAPORATIVE EMISSION LEAK DETECTION
NOTE: A thorough visual inspection of the Evap system hoses, tubes, and connections may save time in
your diagnosis. Look for any physical damage or signs of wetness at connections. The strong smell of fuel
vapors may also aid diagnosis.
To continue testing, you will need Miller Tool #8404A Evaporative Emissions Leak Detector (EELD).
Remove the Air supply hose from the service port (if equipped) or from the #8404-ADP adapter.
Connect the SMOKE supply tip (black hose) to the service port (if equipped)or to the #8404-ADP adapter.
Set the smoke/air control switch to SMOKE.
NOTE: The flow meter indicator ball will not move in the smoke mode.
Press the remote smoke/air start button.
NOTE: Make sure that smoke has filled the EVAP system by continuing to presstheremotesmoke/airstart
button, remove the vehicle fuel cap, and wait for the smoke to exit. Once smoke is indicated reinstall the
fuel cap.
NOTE: For optimal performance, introduce smoke into the system for an additional 60 seconds; continue
introducing smoke at 15 second intervals, as necessary.
While still holding the remote smoke/air start button, use the white light(#8404-CLL) to follow the EVAP system
path, and look for the source of the leak indicated by exiting smoke.
If a leak is concealed from view (i.e., top of fuel tank), release the remotesmoke/air start button, and use the ultra-
violet (UV) black light #8404-UVL and the yellow goggles 8404-20 to look for residual traces of dye that is left
behind by the smoke.
The exiting smoke deposits a residual fluid that is either bright green or bright yellow in color when viewed with a
UV light.
NOTE: Carefully inspect the vent side of the EVAP Canister. Due to the filtering system in the canister the
smoke may not be as thick. Introducing smoke into the filtered side of the canister may assist in locating
the leak.
NOTE: The EVAP System is divided into three zones. A leak from any of these zonescancausethisDTCto
set. The lists below specify the possible leak points in that specific zone. For further assistance see the
Zone Identification Charts below.
ZONE 1
1FuelCap
2 Recirculation Check Valve.
3 Vapor Recirculation Line.
4 Signal Vapor Line for FVM.
5 Flow Management Valve.
6 Fuel Tank to Canister Vapor Line connection.
7 Fuel Tank Vent (Check Valve).
8 Vapor Line to Canister.
9 Flow Control Orfice.
10 Control Valve.
11 Liquid Trap.
12 Fuel Tank.
13 Check valve.
14 Fuel Fill Tube to Tank connector.
15 Fuel Fill Tube
Damaged or disconnected EVAP system components.
ZONE 2
1Filter.
2LDP.
3 Canister Vent Line.
P0460-FUEL LEVEL SENDING UNIT NO CHANGE OVER MILES
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Engine running and fuel level either below 15% or above 85% of capacity.
Set Condition:
The PCM sees low fuel, less than 15%, for more than 120 miles or fuel level does not change by at least 4%
for more than 250 miles.
Possible Causes
PHYSICALLY DAMAGED/DEFORMED/OBSTRUCTED FUEL TANK
FUEL LEVEL SENSOR
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.CHECKING FOR A DAMAGED/DEFORMED/OBSTRUCTED FUEL TANK
Turn the ignition off.
WARNING: WARNING: The fuel system is under a constant pressure, even with the engine off. Before test-
ing or servicing any fuel system hose, fitting or line, the fuel system pressure must be released.
Inspect the outside of the fuel tank for defects.
Remove the fuel tank.
Remove the fuel pump module from the fuel tank.
Inspect the inside of the fuel tank for any obstructions or deformities.
Is the fuel tank free from defects?
Ye s>>
Go To 2
No>>
Repair or replace the fuel tank as necessary.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.FUEL LEVEL SENSOR
If there are no possible causes remaining, view repair.
Repair
Replace the Fuel Level Sensor.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
HEAD-CYLINDER-LEFT
DIAGNOSIS AND TESTING - CYLINDER HEAD GASKET
A cylinder head gasket leak can be located between adjacent cylinders or between a cylinder and the adjacent
water jacket.
Possible indications of the cylinder head gasket leaking between adjacent cylinders are:
Loss of engine power
Engine misfiring
Poor fuel economy
Possible indications of the cylinder head gasket leaking between a cylinder and an adjacent water jacket are:
Engine overheating
Loss of coolant
Excessive steam (white smoke) emitting from exhaust
Coolant foaming
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is leaking between adjacentcylinders, follow the procedures in Cyl-
inder Compression Pressure Test (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING). An engine cylinder head
gasket leaking between adjacent cylinders will result in approximately a50 - 70% reduction in compression pres-
sure.
CYLINDER-TO-WATER JACKET LEAKAGE TEST
WARNING: USE EXTREME CAUTION WHEN THE ENGINE IS OPERATING WITH COOLANT PRESSURE CAP
REMOVED.
VISUAL TEST METHOD
With the engine cool, remove the coolant pressure cap. Start the engine andallow it to warm up until thermostat
opens.
If a large combustion/compression pressure leak exists, bubbles will be visible in the coolant.
COOLING SYSTEM TESTER METHOD
WARNING: WITH COOLING SYSTEM TESTER IN PLACE, PRESSURE WILL BUILD UP FAST.EXCESSIVE
PRESSURE BUILT UP, BY CONTINUOUS ENGINE OPERATION, MUST BE RELEASED TO A SAFE PRESSURE
POINT. NEVER PERMIT PRESSURE TO EXCEED 138 kPa (20 psi).
Install Cooling System Tester 7700 or equivalent to pressure cap neck. Start the engine and observe the tester’s
pressure gauge. If gauge pulsates with every power stroke of a cylinder a combustion pressure leak is evident.
CHEMICAL TEST METHOD
Combustion leaks into the cooling system can also be checked by using Bloc-Chek Kit C-3685-A or equivalent.
Perform test following the procedures supplied with the tool kit.
REMOVAL
1. Disconnect the negative cable from the battery.
2. Raise the vehicle on a hoist.
3. Disconnect the exhaust pipe at the left side exhaust manifold.
4. Drain the engine coolant (Refer to 7 - COOLING - STANDARD PROCEDURE).
5. Lower the vehicle.
6. Remove the intake manifold (Refer to 9 - ENGINE/MANIFOLDS/INTAKE MANIFOLD - REMOVAL).
CYLINDER HEAD
DESCRIPTION
DESCRIPTION - CYLINDER HEAD
The cylinder heads are made of an aluminum alloy. The cylinder head features two valves per cylinder with pressed
in powdered metal valve guides. The cylinder heads also provide enclosures for the timing chain drain, necessitating
unique left and right cylinder heads.
DESCRIPTION - VALVE GUIDES
The valve guides are made of powered metal and are pressed into the cylinderhead. The guides are not replace-
able or serviceable, and valve guide reaming is not recommended. If the guides are worn beyond acceptable limits,
replace the cylinder heads.
DIAGNOSIS AND TESTING
CYLINDER HEAD GASKET
A cylinder head gasket leak can be located between adjacent cylinders or between a cylinder and the adjacent
water jacket.
Possible indications of the cylinder head gasket leaking between adjacent cylinders are:
Loss of engine power
Engine misfiring
Poor fuel economy
Possible indications of the cylinder head gasket leaking between a cylinder and an adjacent water jacket are:
Engine overheating
Loss of coolant
Excessive steam (white smoke) emitting from exhaust
Coolant foaming
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is leaking between adjacentcylinders, follow the procedures in Cyl-
inder Compression Pressure Test (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING). An engine cylinder head
gasket leaking between adjacent cylinders will result in approximately a50 - 70% reduction in compression pres-
sure.
CYLINDER-TO-WATER JACKET LEAKAGE TEST
WARNING: USE EXTREME CAUTION WHEN THE ENGINE IS OPERATING WITH COOLANT PRESSURE CAP
REMOVED.
VISUAL TEST METHOD
With the engine cool, remove the coolant pressure cap. Start the engine andallow it to warm up until thermostat
opens.
If a large combustion/compression pressure leak exists, bubbles will be visible in the coolant.
COOLING SYSTEM TESTER METHOD
WARNING: WITH COOLING SYSTEM TESTER IN PLACE, PRESSURE WILL BUILD UP FAST.EXCESSIVE
PRESSURE BUILT UP, BY CONTINUOUS ENGINE OPERATION, MUST BE RELEASED TO A SAFE PRESSURE
POINT. NEVER PERMIT PRESSURE TO EXCEED 138 kPa (20 psi).
CYLINDER HEAD
OPERATION—CYLINDER HEAD
The cylinder head closes the combustion chamber allowing the pistons to compress the air fuel mixture to the cor-
rect ratio for ignition. The valves located in the cylinder head open and close to either allow clean air into the com-
bustion chamber or to allow the exhaust gases out, depending on the stroke of the engine.
DIAGNOSIS AND TESTING—CYLINDER HEAD GASKET FAILURE
A cylinder head gasket leak can be located between adjacent cylinders or between a cylinder and the adjacent
water jacket.
Possible indications of the cylinder head gasket leaking between adjacent cylinders are:
− Loss of engine power
− Engine misfiring
− Poor fuel economy
Possible indications of the cylinder head gasket leaking between a cylinder and an adjacent water jacket are:
− Engine overheating
− Loss of coolant
− Excessive steam (white smoke) emitting from exhaust
− Coolant foaming
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is leaking between adjacentcylinders, follow the procedures in Cyl-
inder Compression Pressure Test in this section. An engine cylinder head gasket leaking between adjacent cylinders
will result in approximately a 50–70% reduction in compression pressure.
CYLINDER-TO-WATER JACKET LEAKAGE TEST
WARNING: USE EXTREME CAUTION WHEN THE ENGINE IS OPERATING WITH COOLANT PRESSURE CAP
REMOVED.
VISUAL TEST METHOD
With the engine cool, remove the coolant pressure cap. Start the engine andallow it to warm up until thermostat
opens.
If a large combustion/compression pressure leak exists, bubbles will be visible in the coolant.
COOLING SYSTEM TESTER METHOD
WARNING: WITH COOLING SYSTEM TESTER IN PLACE, PRESSURE WILL BUILD UP FAST.EXCESSIVE
PRESSURE BUILT UP, BY CONTINUOUS ENGINE OPERATION, MUST BE RELEASED TO A SAFE PRESSURE
POINT. NEVER PERMIT PRESSURE TO EXCEED 138 kPa (20 psi).
Install Cooling System Tester 7700 or equivalent to pressure cap neck. Start the engine and observe the tester’s
pressure gauge. If gauge pulsates with every power stroke of a cylinder a combustion pressure leak is evident.
CHEMICAL TEST METHOD
Combustion leaks into the cooling system can also be checked by using Bloc-Chek Kit C-3685-A or equivalent.
Perform test following the procedures supplied with the tool kit.