Intercooler

This procedure covers removal and replacement of the intercooler assembly on the 5.9L Cummins diesel engine, including charge air piping and mounting hardware.

Warnings

Tools required

Parts

• Intercooler assembly × 1 — Use OEM specification or aftermarket equivalent
• Charge pipe clamps × 4 — T-bolt style clamps
• Intercooler mounting gaskets × 2 — Use OEM specification
• Intercooler mounting hardware kit × 1 — Bolts and brackets if corroded

Preparation

1. Park vehicle on level surface and set parking brake
2. Disconnect negative battery cable
3. Allow engine to cool completely (minimum 2 hours)
4. Remove front bumper cover to access intercooler area
5. Mark or photograph charge pipe routing and sensor locations for reassembly reference

Procedure

1. 1

   Disconnect intake air temperature sensor
   Locate the intake air temperature sensor. Disconnect the electrical connector by pressing the release tab. If the sensor needs removal, unthread it from its port using the appropriate wrench.
   Torque spec

   Sensor Mounting Bolts11 Nm (8 lb-ft)

   Electrical Connector Bolts7 Nm (5 lb-ft)
2. 2

   Remove charge air pipes from intercooler
   Loosen the charge pipe clamps at the intercooler inlet (from turbocharger) and outlet (to intake manifold) connections. Use hose clamp pliers if equipped with spring clamps, or socket/screwdriver for worm-gear clamps. Carefully twist and pull charge pipes off intercooler connections. Some oil residue is normal.
   ℹ️Mark pipe orientation before removal to ensure correct reinstallation
   Torque spec

   Charge Pipe Clamps4 Nm (3 lb-ft)
3. 3

   Drain intercooler residual oil
   Tip the intercooler forward and drain any accumulated oil into a drain pan. This oil accumulation is normal from turbocharger blow-by. Excessive oil (more than 2-3 ounces) may indicate turbocharger seals require attention.
4. 4

   Remove intercooler mounting bolts
   Remove the intercooler mounting bolts securing the unit to the radiator support brackets. Typical configuration includes 4-6 mounting bolts at the top and bottom brackets. Support the intercooler while removing the final bolts.
   ⚠Intercooler weighs approximately 15-20 lbs. Support during removal to prevent dropping.
   Torque spec

   Intercooler Mounting Bolts15 Nm (11 lb-ft)
5. 5

   Remove intercooler assembly
   Carefully maneuver the intercooler out through the front of the vehicle after removing the grille. May require slight angling or tilting to clear the radiator support and other components. Inspect mounting brackets and rubber isolators for damage. May require slight angling or tilting to clear radiator support and other components. Inspect mounting brackets and rubber isolators for damage.
6. 6

   Inspect and clean mounting surfaces
   Clean the charge pipe boot sealing surfaces on the intercooler inlet and outlet using a shop rag and brake cleaner. Remove any debris, oil residue, and corrosion. Inspect mounting brackets for cracks or damage. Check intercooler fins for damage and debris. Inspect mounting brackets for cracks or damage. Check intercooler fins for damage and debris.
   ℹ️Do not use aggressive abrasives that could damage aluminum surfaces
   Torque spec

   Gasket Surface Bolts20 Nm (15 lb-ft)
7. 7

   Prepare new intercooler
   Unpack new intercooler and verify all mounting points match original. Verify the rubber isolators/mounts are in good condition and transfer them or install new ones if applicable to your specific model year. Verify all connection points are clean and free from shipping debris.
8. 8

   Install intercooler assembly
   Carefully position new intercooler into mounting location, aligning mounting holes with brackets. Thread mounting bolts by hand to ensure proper alignment before tightening. Install all mounting bolts finger-tight first.
9. 9

   Torque intercooler mounting bolts
   Using torque wrench, tighten intercooler mounting bolts in a cross-pattern to ensure even seating. Start with lower bolts, then upper bolts. Apply specified torque for mounting bolt size and location.
   ⚠Over-torquing can crack aluminum mounting ears. Use accurate torque wrench.
   Torque spec

   Intercooler Mounting Bolts15 Nm (11 lb-ft)
10. 10

    Reconnect charge air pipes
    Apply thin film of clean engine oil to inside of charge pipe boots for easier installation. Slide charge pipes onto intercooler inlet and outlet connections, ensuring full seating. Position clamps over boot beads before tightening.
11. 11

    Secure charge pipe clamps
    Tighten all charge pipe clamps to specification using torque wrench. Verify pipes cannot be twisted or pulled off by hand after tightening. Ensure clamps are positioned over raised bead areas on connections.
    ⚠Under-torqued clamps will allow boost leaks. Over-torquing can damage boots.
    Torque spec

    Charge Pipe Clamps4 Nm (3 lb-ft)
12. 12

    Reinstall sensors and connectors
    Reinstall the intake air temperature sensor if removed, threading it into its port and torquing to specification. Reconnect the electrical connector, ensuring positive lock engagement. Verify the connector is fully seated. Reconnect electrical connector, ensuring positive lock engagement. Verify connector is fully seated.
    Torque spec

    Sensor Mounting Bolts11 Nm (8 lb-ft)

    Electrical Connector Bolts7 Nm (5 lb-ft)
13. 13

    Reinstall front bumper cover
    Reinstall the front bumper/valance and grille, aligning all mounting points and fasteners. Secure all bolts and clips. Verify headlight and grille alignment.

Reassembly

1. Reconnect negative battery cable
2. Double-check all clamp connections for proper tightness
3. Verify no tools or parts left in engine compartment
4. Check that all electrical connectors are fully seated and locked

Verification

• Start engine and allow to idle. Listen for air leaks (hissing sounds) around intercooler connections
• Rev engine to 2000 RPM and verify no boost leaks audible
• Test drive vehicle and verify normal boost pressure operation
• Recheck all clamp tightness after first 50 miles of operation
• Monitor intake air temperatures to verify intercooler is functioning properly

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