Complete removal and replacement of the intake manifold assembly on a 2014 Ram 2500 with 6.7L Cummins diesel engine, including all associated sensors, hoses, and fuel system components.

Warnings

Tools required

Parts

• Intake manifold gasket × 1 — Use OEM specification
• Throttle body gasket × 1 — Use OEM specification
• PCV valve O-ring × 1 — Use OEM specification
• Intake manifold cover gasket × 1 — Use OEM specification
• Fuel rail O-rings × 6 — Use OEM specification

Preparation

1. Park vehicle on level surface, engage parking brake, and chock rear wheels
2. Disconnect both negative and positive battery cables to prevent accidental electrical discharge
3. Allow engine to cool completely (minimum 2 hours) to prevent burns and thermal damage to components
4. Remove engine cover by pulling upward on front corners
5. Place fender covers to protect paint from tools and parts
6. Relieve fuel system pressure by removing fuel pump relay and cranking engine until it stalls
7. Photograph or label all electrical connectors and vacuum line routing for reference during reassembly

Procedure

1. 1

   Remove air intake system
   Loosen clamp on air intake tube at turbocharger inlet. Disconnect Mass Airflow (MAF) sensor electrical connector. Remove air filter housing bolts and lift out entire air intake assembly including filter housing and intake tube. Cap turbocharger inlet with clean shop towel to prevent debris entry.
   ⚠Do not allow any debris or foreign material to enter turbocharger or intake system as this will cause severe engine damage.
2. 2

   Disconnect throttle body and EGR components
   Disconnect throttle position sensor electrical connector on throttle body. Remove throttle body mounting bolts and carefully separate throttle body from intake manifold. Disconnect EGR valve electrical connector and all associated vacuum lines (note routing). Remove EGR cooler outlet pipe mounting bolts and set aside.
   ℹ️Throttle body bore may contain carbon deposits. Do not use harsh cleaners on throttle plate or electronics.
   Torque spec

   Throttle Body Bolts10 Nm (7 lb-ft)
3. 3

   Remove intake manifold cover and components
   Remove all cover bolts securing the upper intake manifold cover. Carefully lift cover away and remove gasket. Disconnect all electrical connectors from intake air temperature sensors and manifold-mounted components. Label each connector position if not already photographed.
   Torque spec

   Cover Bolts22 Nm (16 lb-ft)
4. 4

   Disconnect fuel system components
   Place drain pan beneath fuel rail connections. Disconnect fuel supply and return lines using appropriate quick-disconnect tools. Disconnect all six fuel injector electrical connectors. Remove fuel rail mounting bolts in reverse of tightening sequence (consult service manual for exact sequence). Carefully lift fuel rail with injectors attached straight up and out. Cap all fuel openings immediately to prevent contamination.
   ⚠️Residual fuel pressure may still be present. Keep hands and face clear when disconnecting fuel lines. Have shop towels ready to catch fuel spillage.
   ⚠Support fuel rail assembly carefully. Do not allow injectors to hang by fuel lines or wiring harnesses.
   Torque spec

   Fuel Rail Bolts12 Nm (9 lb-ft)
5. 5

   Remove PCV system components
   Disconnect PCV hoses from intake manifold ports. Remove PCV valve by rotating counterclockwise (note installed depth for reinstallation). Remove any additional crankcase ventilation lines or oil separator connections attached to intake manifold. Inspect PCV valve and replace if carbon buildup is excessive.
   Torque spec

   PCV Valve8 Nm (6 lb-ft)
6. 6

   Disconnect remaining intake manifold connections
   Disconnect any remaining vacuum lines, boost pressure sensor connections, and mounting brackets attached to intake manifold. Remove heater hose brackets if they interfere with manifold removal. Support any loose wiring harnesses away from work area with mechanics wire or zip ties.
7. 7

   Remove intake manifold bolts
   Beginning from the outer edges and working toward the center (reverse of tightening sequence), remove all intake manifold mounting bolts. There are typically 12-14 bolts securing the manifold to cylinder head. Keep bolts organized by position as some may be different lengths. Once all bolts are removed, carefully rock manifold side to side to break gasket seal.
   ⚠Do not pry between manifold and cylinder head surfaces as this may cause damage requiring expensive machining repairs.
   Torque spec

   Intake Manifold Bolts25 Nm (18 lb-ft)
8. 8

   Remove intake manifold assembly
   Carefully lift intake manifold straight up and away from cylinder head. Manifold assembly is heavy and awkward, may require assistance or engine hoist for safe removal. Once removed, immediately cover open intake ports on cylinder head with clean shop towels or plastic sheeting to prevent debris entry.
   ⚠️Intake manifold weighs approximately 40-50 lbs. Use proper lifting technique or assistance to prevent back injury or dropping the component.
   ⚠Absolutely no debris, bolts, or tools can be allowed to fall into open intake ports. Even small items will cause catastrophic engine damage.
9. 9

   Clean mounting surfaces
   Remove all old gasket material from cylinder head intake ports and manifold mating surface using plastic scraper. Do not use metal scrapers that could gouge aluminum surfaces. Clean surfaces thoroughly with brake cleaner and lint-free shop towels. Use compressed air to blow out any debris from bolt holes, but keep intake ports covered. Inspect both surfaces for warping, cracks, or damage. Cylinder head surface must be completely clean and dry before installing new gasket.
   ⚠Use only plastic or composite scrapers on aluminum surfaces. Metal scrapers will create grooves that prevent proper sealing.
10. 10

    Install new intake manifold
    Position new intake manifold gasket on cylinder head, ensuring all alignment pins or tabs are properly seated. Carefully lower new or cleaned intake manifold onto gasket, aligning all bolt holes. Thread all intake manifold bolts by hand to ensure proper thread engagement before tightening any bolts. Using torque wrench, tighten bolts to specification in proper sequence from center outward (consult service manual for exact sequence diagram). Make second pass at same torque value to ensure even clamping.
    ⚠Incorrect tightening sequence or over-torquing will warp manifold and cause vacuum leaks. Follow sequence exactly as specified in service manual.
    Torque spec

    Intake Manifold Bolts25 Nm (18 lb-ft)
11. 11

    Reinstall fuel rail assembly
    Install new O-rings on all six fuel injector tips, lubricating lightly with clean diesel fuel. Carefully position fuel rail with injectors into intake manifold ports, ensuring all injectors seat fully. Install fuel rail mounting bolts finger-tight, then torque in proper sequence from center outward to specification. Reconnect all six fuel injector electrical connectors. Reconnect fuel supply and return lines, ensuring positive engagement of quick-connect fittings.
    ⚠Fuel injectors must drop straight down into ports. Any binding or misalignment can damage injector O-rings causing fuel leaks.
    Torque spec

    Fuel Rail Bolts12 Nm (9 lb-ft)
12. 12

    Reinstall PCV and remaining components
    Install new O-ring on PCV valve and torque to specification (do not overtighten plastic valve). Reconnect all PCV hoses and crankcase ventilation lines. Reinstall any brackets, sensors, and wiring harnesses to intake manifold. Install new gasket on intake manifold cover and torque cover bolts to specification in cross pattern.
    Torque spec

    PCV Valve8 Nm (6 lb-ft)

    Cover Bolts22 Nm (16 lb-ft)
13. 13

    Reinstall throttle body and EGR system
    Install new throttle body gasket. Position throttle body on intake manifold and install mounting bolts, torquing to specification in cross pattern. Reconnect throttle position sensor electrical connector. Reinstall EGR cooler outlet pipe and torque mounting bolts to specification. Reconnect EGR valve electrical connector and all vacuum lines according to photos taken during disassembly.
    Torque spec

    Throttle Body Bolts10 Nm (7 lb-ft)
14. 14

    Reinstall air intake system and finalize
    Remove shop towel from turbocharger inlet. Position air intake assembly and filter housing, securing with mounting bolts. Reconnect MAF sensor electrical connector. Tighten air intake tube clamp at turbocharger inlet. Reconnect both battery cables (positive first, then negative). Install engine cover. Verify all electrical connectors, hoses, and brackets are properly secured.

Reassembly

1. Double-check that all electrical connectors are fully seated and locked
2. Verify all vacuum lines and hoses are connected according to original routing photos
3. Ensure no tools, rags, or parts have been left in engine compartment
4. Confirm all fuel line connections are properly engaged and secured

Verification

• Turn ignition to ON position (do not start) and listen for fuel pump priming. Check for fuel leaks at all connections for 30 seconds
• Start engine and allow to idle. Check immediately for any fuel, coolant, or vacuum leaks around intake manifold and fuel rail
• Listen for any abnormal hissing sounds that could indicate vacuum leaks at intake manifold gasket
• Allow engine to reach operating temperature and verify smooth idle with no misfires or rough running
• Check for diagnostic trouble codes using scan tool. Clear any codes related to battery disconnect and verify no new fuel system or sensor codes appear
• Test drive vehicle under light load and verify normal throttle response and power delivery
• After test drive, recheck all connections for leaks and verify intake manifold bolts have not loosened

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