GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2001 🢒 DeVille 🢒 Engine 🢒 Engine Mechanical - 2.5L (LE8) 🢒 Intake Manifold Installation

    Object Number: 644091 Size: SH
  1. Install the new intake manifold gaskets (1) onto the cylinder heads.

    2. Object Number: 648019 Size: SH

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  2. Install the intake manifold. Secure the intake manifold with the 8 bolts and 4 nuts.

    3. Tighten
    Tighten the bolts and nuts to 23 N·m (16.5 lb ft).


    Object Number: 644089 Size: SH
  3. Install the new throttle body gasket to the intake collector.
  4. Install the throttle body (2) to the intake collector (1). Secure the throttle body with the 2 bolts and 2 nuts.

    5. Tighten
    Tighten the nuts and bolts to 12 N·m (8.5 lb ft).


    Object Number: 644066 Size: SH
  5. Install the intake collector (1) and the throttle body (2) as an assembly to the intake manifold (3) with a new gasket. Secure with the 4 nuts and 2 bolts.

    6. Tighten
    Tighten the nuts and bolts to 12 N·m (8.5 lb ft).


    Object Number: 647999 Size: SH
  6. Install the idle air control (IAC) valve with a new gasket.
  7. Connect the following hoses:
    8. • The heater hose (2)
    • The EVAP canister hose (1)
    • The fuel feed hose (4)
    • The fuel return hose (3)
    • The tank pressure control solenoid valve hose

    Object Number: 648002 Size: SH
  8. Install the exhaust gas recirculation (EGR) pipe (4).
  9. Connect the following hoses:
    10. • The PCV hose to the cylinder head cover (9)
    • The breather hose to the throttle body (6)
    • The EVAP canister purge valve hose (1)
    • The water hose (8)
    • The heater hoses (3, 5)
  10. Connect the following electrical connectors:
    11. • The manifold differential pressure (MDP) sensor
    • The EVAP canister purge valve (1)
    • The exhaust gas recirculation (EGR) valve (2)

    Object Number: 648017 Size: SH
  11. Install the clamp bracket (4) to intake collector.
  12. Install the ground terminal (5) to intake collector.
  13. Connect the following electrical connectors:
    14. • The throttle position (TP) sensor (2)
    • The mass air flow (MAF) sensor (1)
    • The idle air control (IAC) valve (3)

    Object Number: 648018 Size: SH
  14. Connect the injector wire coupler (1).

    15. Object Number: 648013 Size: SH
  15. Connect the water hoses (3) to the throttle body.