performance diagnostic procedures

Performance Diagnostic Procedures

F-Super Duty

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2008 PCED 6.4L Diesel SECTION 4: Diagnostic Subroutines

Procedure revision date: 03/16/2011

of 25Performance Diagnostic Procedures

8/28/2017mk:@MSITStore:C:\Users\Dan\Desktop\2008%20PCED%206.4L%20Manual.chm::/t3/v8...

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1. Visual Engine/Chassis Inspection

Purpose:

The purpose of this test is to check the general condition of the engine and chassis.

Visual Engine/Chassis Inspection

� Verify there are no fluid or pressure leaks.

� Inspect all wire connections for damage.

� Inspect the manifold absolute pressure (MAP) sensor, intake air temperature 2 (IAT2) sensor, charge air cooler (CAC), and intake for leaks.

Recommended Procedure:

� Inspect for a leak around the MAP sensor.

� Inspect for a leak around the IAT2 sensor.

� Inspect the fuel system, including the fuel tank, fuel pump, fuel filter housing and fuel lines, for kinks, bends or leakage.

� Inspect for coolant leaks at the radiator and coolant hoses. Check the coolant level.

� Inspect wiring for correct routing, and verify no rubbing or chafing has occurred.

� Inspect all sensors, and verify the connectors are properly secured.

� Inspect the CAC hoses for leaks.

Possible Causes:

� Loose or leaking fuel lines

� Kinked or blocked fuel lines

� Fuel or oil leaks

� Coolant leaks

� Restricted or open CAC hose

� Incorrect connections

Tools Required:

Inspection light

2. Check Engine Oil Level

Fuel Oil Coolant Electrical Hoses Leaks

Method Check

Visual



WARNING: SMOKING OR OPEN FLAME OF ANY TYPE MUST NOT BE PRESENT WHEN WORKING NEAR FUEL OR FUEL VAPOR. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN PERSONAL INJURY.

NOTICE: Only use ultra low sulfur diesel fuel that is 5% or less biodiesel with this vehicle. Use of any other fuel type may damage the vehicle or cause an emission concern. Refer to the Owner's Literature for more information.

Note: If directed here from a pinpoint test, return to the pinpoint test after carrying out this procedure.

Note: If the engine oil has diesel fuel contamination, the engine oil appears thin and watery, and has a diesel fuel odor. If the engine oil has coolant contamination, the engine oil appears milky white and has an ethylene glycol odor.

Purpose:

The purpose of this test is to verify the correct engine oil quality and level.

Check Engine Oil Level

� Check for aftermarket performance products.

� Check for contaminants (fuel, coolant).

� Correct grade/viscosity.

� Miles/hours on engine oil, correct level.


Check for aftermarket performance products. If aftermarket performance products are present, return to original equipment manufacturers (OEM) components as necessary. Aftermarket performance products affect the correct operation of the regeneration process which may affect engine oil level.

Due to the size of the engine oil system, it is critical when checking the engine oil level, to make sure the vehicle is parked on a level surface and the engine has been turned off for at least 10 minutes to make sure that the engine oil in the upper parts of the engine has returned to the oil pan.

Check for the correct engine oil level using the oil level indicator with the vehicle on level ground.

If the engine oil level on the oil level indicator is overfull, it is possible the engine was incorrectly repaired or fuel or coolant is diluting the engine oil and filling the crankcase. Recheck the engine oil level. Remove and clean the oil level indicator. Reinsert the oil level indicator into the oil level indicator tube until only the oil level indicator handle touches the top of the oil level indicator tube.

Method Check

Visual



Oil Level Indicator Offset

If directed to this test from a pinpoint test and the engine oil level is correct, return to the pinpoint test.

If not directed to this test from a pinpoint test and the engine oil level is correct, continue to Step 3 Sufficient Clean Fuel Test, in this section to continue diagnosis.

If the engine oil level is overfull, check the CAC for contamination. If the CAC has engine oil, coolant, fuel or metal contamination, a thorough cleaning of the CAC system is necessary. Refer to the Workshop Manual section 303-12 for correct cleaning procedures. Clean and mark the oil level indicator.

Engine Oil Level Indication

Check for recent fuel system repairs which may have caused fuel leaks into the engine crankcase. If a fuel system repair was made and the engine oil was not changed, change the engine oil, mark the oil level indicator and carry out the Fuel System Leak Test in this section to continue diagnosis.

Check the maintenance records for engine idle time, mileage and vehicle usage since the last engine oil change. Oil that has had extended drain intervals has increased viscosity (becomes thicker) and makes engine cranking more difficult and starting less reliable at temperatures below freezing. Refer to the lube oil chart in the Workshop Manual or Owner's Literature for the correct engine oil selection for temperature conditions. If records indicate insufficient engine oil changes, change the engine oil, mark the oil level indicator and carry out the Fuel System Leak Test in this section to continue diagnosis.

Check for biodiesel fuel of greater than 5% or high sulphur diesel fuel. Biodiesel fuel concentration of greater than 5% or use of high sulphur content fuel can cause increased fuel dilution.

If the engine oil level is overfull, GO to Pinpoint Test AB to continue diagnosis.



Possible Causes:

� Engine oil level low — engine oil leak, engine oil consumption, incorrect repair

� Engine oil level high — incorrect repair, fuel dilution

� Engine oil contamination with coolant — engine oil cooler, front cover porosity, head gasket, porosity

� Engine oil contamination with diesel fuel — fuel injector leak, high pressure fuel injection pump leak

Tools Required:

None

3. Sufficient Clean Fuel Test

NOTICE: Only use ultra low sulfur diesel fuel that is 5% or less biodiesel with this vehicle. Use of any other fuel type may damage the vehicle or cause an emission concern. Refer to the Owner's Literature for more information.

Purpose:

The purpose of this test is to verify the fuel quality.

Sufficient Clean Fuel Test

� Check for illumination of the water in fuel (WIF) indicator.

� Drain a fuel sample from the fuel conditioning module.


Open the drain valve integrated in the fuel conditioning module and drain fuel into a clear 1 liter container. Close the drain valve. The flow out of the drain valve should be steady and should produce at least 1 liter/1 quart of fuel within 2 minutes. If the volume of the fuel collected within 2 minutes is short of the required 1 liter/1 quart there may be insufficient amount of fuel in the tank and the fuel level may not be correctly indicated on the fuel level gauge. If a fuel level indication concern is suspected, refer to the Workshop Manual Section 413-01 to continue diagnosis.

Observe the WIF indicator. If the indicator is illuminated, the fuel may be contaminated with water.

Inspect the fuel in the container. It should be clear, not cloudy. It also should be free of water and contaminants. Dyed red or blue fuel indicates off-highway fuel.

The fuel sample should not indicate evidence of waxing or gelling. Waxing or gelling in some fuels in cold weather could clog fuel filters and the fuel pump and cause restrictions in the fuel or low fuel pressure.

Some sediment and water may be present in the fuel sample if the fuel filter has not been replaced for a prolonged period of time and/or if the sediment and water have not been drained recently. If that is the case,

Method Check

Visual



a second sample may be required to determine fuel quality.

Fuel Conditioning Module Drain Valve

Possible Causes:

� Biodiesel-water separation, seal degradation, corrosion

� Corrosion to fuel system components

� No fuel in the tank

� Fuel supply line broken or crimped

� Fuel jelled

� Fuel quality

� Pickup tube screen in tank restricted

� Restricted fuel filters

Cloudy fuel indicates that the fuel may not be a suitable grade for cold temperatures.

Excessive water or contaminants may indicate that the tank and fuel system may need to be flushed and cleaned.

Tools Required:

Clear container — approximately 0.95 L (1 quart)

4. Carry Out The Key On Engine Off (KOEO) On-Demand Self-Test

Purpose:

The purpose of this test is to determine if the powertrain control module (PCM) has detected concerns that would cause a performance concern.

Carry Out The KOEO On-Demand Self-Test



� Use the scan tool. Diagnostic trouble code (DTCs) set during this test are current faults.


Connect the scan tool. Turn off all accessories. If the vehicle is equipped with a power take-off (PTO) system or auxiliary idle control, it must be turned off to carry out the self-test.

� Carry out the necessary vehicle preparation and a visual inspection. Refer to Section 2, Quick Test Operation .

� Refer to the scan tool operating manual for instructions.

� Ignition ON, engine OFF.

� Follow the operating instructions from the diagnostic menu.

� Carry out a KOEO on-demand self-test.

� Record the DTCs, freeze frame information, and refer to the appropriate pinpoint test to continue diagnosis.

Tools Required:

Scan tool

5. Retrieve Continuous Diagnostic Trouble Codes (DTCs)

Purpose:

The purpose of this test is to determine if the PCM has detected any historical or intermittent fault conditions that would cause a performance concern. The condition that caused a continuous DTC may no longer exist.

Retrieve Continuous DTCs


Connect the scan tool. Turn off all accessories. If the vehicle is equipped with a power take-off (PTO) system or auxiliary idle control, it must be turned off to carry out the self-tests.




� Follow the operating instructions from the menu.

Diagnostic Trouble Codes




� Record the continuous DTCs and freeze frame information from the PCM and the transmission control module (TCM) and refer to the appropriate pinpoint test for continuous DTC diagnostics.

� Clear the continuous DTCs after a repair is made.

Tools Required:

Scan tool

6. KOEO Injector Electrical Self-Test

Purpose:

Note: Before carrying out the KOEO injector electrical self-test, allow the engine to stabilize at the temperature necessary to recreate the symptom. Access the PCM and record the freeze frame data. The freeze frame data contains information which can be used to recreate original conditions that caused the symptom. Refer to Section 2, Freeze Frame Data for more information.

The purpose of this test is to determine if the injectors are functioning.

KOEO Injector Electrical Self-Test

� Use the scan tool. Injector DTCs will be transmitted after the self-test is completed.

Cylinder and Fuel Injector Location


This test determines if the injectors and circuits are correctly operating. If an electrical concern is present, a DTC sets and outputs on the data link at the end of the test when requested by a scan tool.

Injector Trouble Codes



� Turn off all accessories. If the vehicle is equipped with a PTO system or auxiliary idle control, it must be turned off to carry out the self-tests.




� Carry out the KOEO Injector Electrical Self-Test.

� Ignition in OFF position.

� Record the DTCs and carry out the appropriate pinpoint test.

Possible Causes:

� Open or shorted injector circuit

� Injector connector

� Injector

Tools Required:

Scan tool

7. Carry Out The Key On Engine Running (KOER) On-Demand Self-Test

Purpose:

The purpose of this test is to determine if the PCM has detected any fault conditions that would cause a performance concern while the engine is running. The KOER self-test carries out step tests on the high and low fuel pressure systems and the exhaust pressure system.

Step tests are PCM controlled tests where the PCM commands a specific exhaust pressure or fuel rail pressure (FRP) and then measures the result. If a predetermined threshold is not reached, a DTC is generated. This test can be carried out at any engine temperature.

Carry Out The KOER On-Demand Self-Test

� The self-test verifies the FRP, exhaust gas recirculation (EGR), and turbocharger systems performance.


Note: The engine runs rough during this test.

Connect the scan tool. Turn off all accessories. If the vehicle is equipped with a PTO system or auxiliary idle control, it must be turned off to carry out the self-test.

� Carry out the necessary vehicle preparation and visual inspection. Refer to Section 2, Quick Test




Operation .


� Ignition ON, engine running.

� Follow the operating instructions from the diagnostic menu.

� Carry out a KOER On Demand Self-Test.

� Record the DTCs and refer to the appropriate pinpoint test.

Tools Required:

Scan tool

8. Power Balance Test

Purpose:

Note: Before carrying out the power balance test, allow the engine to stabilize at the temperature necessary to recreate the symptom. Access the PCM and record the freeze frame data. The freeze frame data contains information which can be used to recreate original conditions that caused the symptom. Refer to Section 2, Freeze Frame Data for more information.

Note: The contributing power cylinders that immediately follow the non-contributing power cylinders in the firing order may be affected. The affected power cylinders may not be able to fully recover the crankshaft speed, causing them to display below average contributing power cylinders and to be incorrectly identified as the non-contributing power cylinder. Therefore, only the cylinders that deviate the most from the average should be identified as the non-contributing power cylinder. Single or inconsistent non-contributing power cylinder traces may be caused by a natural variation in the crankshaft speed and should be ignored.

The purpose of this test is to determine if the fuel injectors are operating correctly by observing individual cylinder contribution while carrying out the power balance test.

Power Balance Test

Note: Disregard any DTCs set as a result of the Power Balance Test.

� Use the scan tool to carry out the Power Balance Test.

� Monitor individual cylinder contribution and record the consistently non-contributing power cylinders.


Cylinder and Fuel Injector Location

Non - Contributing Power Cylinders At Engine Idle Speed

Non - Contributing Power Cylinders Off Engine Idle Speed or Under Load



At Engine Idle Speed Test

Note: The cylinder contribution test or enhanced power balance test must be carried out while the vehicle is stationary and not in motion. At no time should manual input through the accelerator pedal occur during these tests. Do not carry out this test while driving.

Note: This procedure is to be carried out at engine idle speed. Concerns that are experienced at off engine idle speed or under load conditions are addressed in the Off Engine Idle Speed or Under Load Test.

� Connect the scan tool.

� Ignition ON, engine Running.

� Access the Power Balance Test.

� Evaluate each cylinders performance and compare to specification plus or minus 15 RPM.

� If the performance of all cylinders are within plus or minus 15 RPM, select the manual fuel injector balance test on the scan tool and evaluate each cylinders performance while comparing to specification plus or minus 15 RPM. If the performance of all cylinders are within plus or minus 15 RPM, no concern is present.

� If the performance of any cylinders are not within plus or minus 15 RPM, record the consistently non-contributing power cylinders and carry out the Off Engine Idle Speed or Under Load Test in this section to continue diagnosis.

Off Engine Idle Speed or Under Load Test

Note: This procedure is to be carried out for concerns that are experienced at off engine idle speed or under load.

Note: Disregard any DTCs set as a result of the Power Balance test.


� Ignition ON, engine Running.

� Access the FRP_DSD PID and increase the fuel pressure to between 105-113 MPa (15,000 to 16,000 psi).

� Access the Power Balance Test.

� Evaluate each cylinders performance and compare to specification plus or minus 15 RPM.

� Select the manual fuel injector balance test on the scan tool. Evaluate each cylinders performance while comparing to specification plus or minus 15 RPM.

� Record the consistently non-contributing power cylinders.

Tools Required:



Scan tool

9. High Pressure Fuel System Test

Note: Carry out the Electric Fuel Pump Pressure test before carrying out the High Pressure Fuel System test.

Purpose:

The purpose of this test is to determine if the high pressure fuel system is able to reach and maintain the requested desired fuel pressure for a calibrated amount of time. This procedure may be used to assist in diagnosing hard start/no start or driveability concerns.

High Pressure Fuel System Test

Note: Depending on the engine state the fuel rail pressure may vary at idle from 34.47 MPa (5,000 PSI) to 51.71 MPa (7,500 PSI).

� Use the scan tool to carry out the High Pressure Fuel System test.

� Visually check for engine compartment fuel leaks during this test.


Note: Follow the scan tool directions when carrying out the high pressure fuel system test.

This test determines if the high pressure fuel system is able to maintain the requested fuel pressure for a calibrated amount of time.

� Turn off all accessories. If the vehicle is equipped with a PTO system or auxiliary idle control, it must be turned off to carry out the high pressure fuel system test. Refer to the scan tool operating manual for instructions.

� Ignition in OFF position.

� Carry out the high pressure fuel system test.

� Visually check for engine compartment fuel leaks during this test.

� If visible fuel leaks are present, refer to the Workshop Manual Section 303-04 Fuel Charging And Controls.

� If the measured variation is outside of the specifications and no visible fuel leaks are present, GO to Pinpoint Test ME .

Commanded Pressure Measured Pressure Specification Measured Variation

34.47 MPa (5,000 PSI) +/- 2.0 MPa (+/- 290 PSI)

68.95 MPa (10,000 PSI) +/- 2.0 MPa (+/- 290 PSI)

103.42MPa (15,000 PSI) +/- 3.0 MPa (+/- 435 PSI)

137.90 MPa (20,000 PSI) +/- 3.0 MPa (+/- 435 PSI)

169.96 MPa (24,650 PSI) +/- 3.0 MPa (+/- 435 PSI)



Possible Causes:

� High pressure fuel injection pump

� Fuel pressure control valve

� Fuel volume control valve

� High pressure fuel system leak

� Fuel injectors

Tools Required:

Scan tool

10. Intake Restriction Test

Purpose:

This purpose of this test is verify an intake air or exhaust restriction is not contributing to a low power condition. If the engine does have a high intake air restriction, a considerable amount of black or blue smoke may be produced.

Intake Restriction

� Check air filter restriction gauge and indicator.

� Measure the vacuum on clean side of intake air system at wide open throttle (WOT) with a Magnehelic Gauge® 0-60 in-H 2 O Bar (part of DSL ENG Pressure Test Kit 014-00761 or equivalent).


Inspect the air cleaner inlet and ducting to make sure it is not blocked or collapsed. Inspect the air cleaner housing and filter for proper installation.

Inspect for any indication of water intrusion into air cleaner and filter.

If necessary, use DSL ENG Pressure Test Kit 014-00761 or equivalent to install a Magnehelic Gauge® on the port on the air cleaner and measure restriction at high idle.

Air Filter Restriction Gauge

Instrument Specification Measurement

Magnehelic Gauge® / Filter Restriction Gauge 2-25 in-H 2 O



Possible Causes:

� Snow or other foreign material may restrict airflow at the air inlet

� Misrouted air cleaner ducting

� On engines recently repaired, rags or cap plugs may have been inadvertently left in an air inlet pipe

Tools Required:

Magnehelic Gauge® 0-60 in-H 2 O Bar (part of DSL ENG Pressure Test Kit 014-00761 or equivalent)

11. Exhaust Gas Recirculation (EGR) System Test

Purpose:

The purpose of this test is to check the EGR valve travel positions.

EGR Position


� Use the scan tool to command the EGRVPDES PID.

� Monitor the EGRVP PID to calculate travel.

EGR Valve Position Sensor Approximate Values

EGRVPDES PID EGRVP PID

0% 1.1 V

10% 1.39 V

20% 1.66 V

30% 1.98 V

40% 2.27 V



Correct concern causing out of specification values before continuing.




� Access the EGRVP PID and record the closed EGR valve position voltage.

� Access EGRVPDES PID and command the EGR valve from 0% to 100%.

� Record the EGR valve open position voltage.

� Subtract the closed EGR valve position voltage from the open EGR valve position voltage.

� If the valve travel and travel voltage are below specification, install a new EGR valve. Refer to the Workshop Manual Section 303-08, Engine Emission Control. Reset the keep alive memory (KAM), refer to Section 2, Resetting The Keep Alive Memory (KAM) . Clear the DTCs. Repeat the self-test.

Possible Causes:

� EGR control circuit

� EGR valve

Purpose:

The purpose of this test is to check the operation of the intake throttle actuator. A MAP PID change greater than 3 psi is an indication of normal intake throttle actuator operation.

Intake Throttle Position


� Use the scan tool to command the EGRTP PID.

� Monitor the MAP PID while commanding the EGRTP PID.

50% 2.53 V

60% 2.78 V

70% 3.07 V

80% 3.4 V

90% 3.72 V

100% 3.99 V

Instrument Specification Actual

Scan Tool 0% (Closed) 0.4 - 1.5 volts

____ Closed

100% (Open) 3.3 - 4.7 volts

____ Open

Travel greater than 2.71 volts

____ Travel






� Access the EGRTP PID and command the intake throttle from open (5%) to close (95%).

� The engine should run normal when the intake throttle is open (MAP PID approximately 14.35 psi), engine may run rough when 85% closed (MAP PID approximately 9.2 psi) and the engine should stall or almost stall when the intake throttle is closed.

� If the MAP PID value does not change more than 3 psi, GO to Pinpoint Test AX . If the MAP PID value changes more than 3 psi, no concern is present.

Possible Causes:

� Intake throttle actuator circuitry

� Intake throttle actuator

Tools Required:

Scan tool

12. Exhaust Restriction Test

Purpose:

The purpose of this test is to determine if an exhaust system restriction is causing a performance problem.

Exhaust Restriction

� Visually inspect the exhaust system for damage.

� Monitor the EBP_A PID with the scan tool and the engine temperature greater than 70°C (158°F) at 3,800 RPM with the vehicle in PARK/NEUTRAL.

Instrument Specification Actual

Scan Tool 5% (Open) Engine runs normal

(MAP PID approximately 14.35 psi)

Open ____

85% (Partially Closed) Engine may run rough

(MAP PID approximately 9.2 psi)

Partially Closed ____

95% (Closed) Engine stalls or almost stalls

Closed ____

Result Engine runs normal when open (MAP PID approximately 14.35 psi), engine may

run rough when 85% closed (MAP PID approximately 9.2 psi) and engine stalls or almost stalls when closed

Result ____




Connect the scan tool. Access and monitor the EBP_A and RPM PIDS.

� Increase the engine speed to 3,800 RPM.

� Record the EBP_A PID value.

� A low RPM or an EBP_A PID value greater than 244 kPa (35 psi) indicates a restricted exhaust condition.

Possible Causes:

� Collapsed or restricted tail pipe

� Restricted oxidation catalytic converter (OC)

� Restricted diesel particulate filter

� Damaged muffler

� Turbocharger

Tools Required:

Scan tool

13. Electric Fuel Pump Pressure

Purpose:

The purpose of this test is to verify the fuel system pressure.

Electric Fuel Pump Pressure

� Measure the fuel pressure using the Fuel Line Adapter 310-159 or equivalent.

� Road test the vehicle with the engine at full load condition.

Note: If using a scan tool for the fuel pump pressure test, the scan tool value may vary by 10% on the 20.7 kPa (3 psi) specification.

If pressure fails low, go to test 14, Fuel Conditioning Module Inlet Restriction Test.

If fuel pressure is above specification, check the fuel return lines for a restriction.

Parameter Specification Measurement

EBP_A 244 kPa (35 psi) MAX at 3,800 RPM


0-200 kPa (0-30 psi) gauge 20.7-55.2 kPa (3-8 psi)



If no restriction is present, install a new fuel pressure regulator valve in the secondary fuel filter housing.


� Verify there is fuel in the tank.

� Disconnect the fuel line on the outlet side of the fuel conditioning module. Install the Fuel Line Adapter 310-159 or equivalent and the Magnehelic Gauge® 0-200 kPa (0-30 psi) Bar (part of DSL ENG Pressure Test Kit 014-00761 or equivalent). Measure the fuel pressure with the ignition in the ON position and the engine OFF. If fuel pressure is below 20.7 kPa (3 psi), go to the next step to verify no restriction.

� Road test the vehicle at a full load condition.

If pressure fails low, go to test 14, Fuel Conditioning Module Inlet Restriction Test.

If fuel pressure is above specification, check the fuel return lines for a restriction.

If no restriction is present, install a new fuel pressure regulator valve in the secondary fuel filter housing.

Possible Causes:

� Fuel return line restriction

� Fuel pressure regulator valve in the secondary fuel filter housing

Tools Required:

Magnehelic Gauge® 0-200 kPa (0-30 psi) Bar (part of DSL ENG Pressure Test Kit 014-00761 or equivalent)

Fuel Line Adapter 310-159 or equivalent

14. Fuel Conditioning Module Inlet Restriction Test

Purpose:

The purpose of this test is to isolate the cause of low fuel pressure.



Electric Fuel Pump Inlet Restriction

Measure restriction at fuel pump inlet.


Disconnect the fuel line to the inlet side of the fuel conditioning module. Install the Fuel Line Adapter 310-159 or equivalent and the vacuum gauge 0-30 in-Hg vacuum. Measure the restriction at wide open throttle (WOT) (maximum engine speed out of gear with the brakes set and the wheels blocked). If restriction is greater than 6 in-Hg, there is a restriction between the fuel pump and the fuel tank. If the restriction is less than 6 in-Hg, inspect both fuel filters. If the filters are OK, install a new fuel conditioning module. Refer to the Workshop Manual Section 303-04, Fuel Charging and Controls.

Possible Causes:

� Fuel line restriction

� Fuel filters

� Fuel conditioning module

Tools Required:

Fuel Line Adapter 310-159 or equivalent

Vacuum Gauge (part of DSL ENG Pressure Test Kit 014-00761 or equivalent)

15. Boost Pressure Test

Purpose:


0-30 in-Hg Vacuum gauge 6 in-Hg MAX



The purpose of this test is to determine if the engine can develop sufficient boost.

Boost Pressure Test

� Carefully inspect the CAC tubes/connections, turbocharger connections, MAP and IAT2 sensors for signs of damage or leaks.

� Carry out the boost pressure test at 3,300 RPM minimum.

� Monitor the MGP and RPM PIDS with the scan tool.

� Road test — select the appropriate gear to obtain desired engine speed and full load condition.


Note: If the test fails low, inspect the turbocharger blades for damage. GO to Pinpoint Test KA to check the turbocharger operation.

Boost pressure levels out after 3,300 RPM. This is best accomplished either climbing a hill or with the vehicle fully loaded.



� Access and monitor the MGP and RPM PIDS.

� After the engine is up to operating temperature, find an open section of road and select the best gear to achieve a 3,300 RPM acceleration.

� With the accelerator at WOT, record the highest boost pressure reading while accelerating through the 2,500-3,300 RPM range.

Possible Causes:

� Leak around MAP sensor

� Leak around IAT2 sensor

� Leaking intake, hoses or fittings

� Turbocharger

� Base engine

� CAC tubes leaking

� CAC

� EGR sticking

Tools Required

Scan tool

16. Crankcase Pressure Test

Purpose:

Parameter Specification Measurement

MGP 26 PSIG minimum



The purpose of this test is to measure the crankcase pressure. Crankcase pressure is a measure of how well the cylinders are sealing.

Crankcase Pressure Test

� Measure the pressure at the oil fill tube with Adapter, Crankcase Pressure Test 303-758, with the engine at 70°C (158°F) minimum.

� Block the breather tube.

� Measure with no load at 3,000 RPM.

If greater than 10 in-H 2 O, refer to the Workshop Manual, Section 303-01, Engine System Component Test

compression test-compression gauge check to continue diagnosis.


Note: Do not plug hole on Adapter, Crankcase Pressure Test 303-758.

Make sure the engine is at operating temperature. A cold engine gives higher readings. Remove the breather tube from the air cleaner tube. Block both ends of the breather tube with the caps provided in DSL ENG Pressure Test Kit 014-00761 or equivalent.


0-60 in-H 2 O Magnehelic® gauge Less than 10 in-H 2 O



Install the Adapter, Crankcase Pressure Test 303-758 in the oil fill cap hole. Plumb to the Magnehelic Gauge® in the gauge block. Make sure the Magnehelic Gauge® has been zeroed.

Start the engine and operate at 3,000 RPM. Hold for 30 seconds minimum and take a stabilized reading. Do not block the hole at the top of the restriction tool.

Possible Causes:

� Broken or worn compression rings

� Polished cylinder bores

� Leaking or bent valves

Inspect the intake air system. If the intake air system allows dirt to enter the cylinders, it will quickly dust the engine causing high crankcase pressure.

Tools Required:

� Adapter, Crankcase Pressure Test 303-758 or equivalent

� Magnehelic Gauge® (part of DSL ENG Pressure Test Kit 014-00761)

� Protective screen

� Hose

� Screw clamps



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