How to remove intake manifold on 2005 Buick Lesabre

You didn't post the size of your engine so please pick the appropriate one:

3.8L

1. Relieve the fuel system pressure.
   
2. Drain the cooling system.
   

1. Remove or disconnect the following:
2. Negative battery cable
   

• Supercharger
  
• Thermostat housing
  
• Exhaust Gas Recirculation (EGR) tube at the intake manifold
  
• Engine Control Temperature (ECT) sensor
  
• Intake manifold
  

To install:

1. Install or connect the following:
   
   • Intake manifold with new gaskets. Torque the bolts, working from the center out, to 11 ft. lbs. (15 Nm).
     
   • ECT sensor connector
     
   • EGR tube to the intake manifold
     
   • Thermostat housing
     
   • Supercharger
     
   • Negative battery cable
     
2. Refill and bleed the cooling system.
   
3. Run the engine and check for leaks and proper engine operation.
   

4.6L
4.6L Engine

1. Remove the brake booster hose from the throttle body.
   
2. Remove the fuel pressure regulator vacuum tube from the fuel pressure regulator and the water crossover.
   
3. Remove the PCV fresh air feed tube from the camshaft cover and the throttle body.
   
4. Remove the PCV dirty air tube from the PCV orifice in the right camshaft cover and from the intake manifold.
   
5. Disconnect the fuel injector electrical connectors from the fuel injectors.
   
6. Remove the fuel injector wiring harness.
   
7. Remove the fuel rail bracket nut from the engine lift bracket.
   
8. Remove the fuel rail studs.
   
9. Lift and remove the fuel rail with injectors.
   
10. Loosen the plenum duct clamp in order to remove the intake manifold.
    
11. Remove the intake manifold bolts.
    
12. Remove the intake manifold.
    

To install:

1. Install the intake manifold, fitting the plenum duct over the intake manifold duct.
   
2. Loosely install the intake manifold bolts.
   

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Intake manifold torque sequence-4.6L engine

2. Tighten the intake manifold bolts in sequence. Tighten the intake manifold bolts to 89 inch lbs. (10 Nm).
   
4. Tighten the plenum duct clamp to the intake manifold. Tighten the plenum duct clamp to 24 inch lbs. (2.75 Nm).
   
5. Inspect the fuel injector O-rings. Ensure the fuel injector O-rings are not missing, misaligned or damaged. Replace the O-rings if necessary.
   
6. Lubricate the intake manifold fuel injector bores with light mineral oil (GM P/N 9981704), clean engine oil, or equivalent.
   
7. Install the fuel rail with fuel injectors as an assembly.
   
8. Install the fuel rail studs. Tighten the fuel rail studs to 80 inch lbs. (9 Nm).
   
9. Install the fuel rail bracket nut to the engine lift bracket. Tighten the fuel rail bracket nut to 89 inch lbs. (10 Nm).
   
10. Install the fuel injector wiring harness.
    
11. Connect the fuel injector electrical connectors to the fuel injectors.
    
12. Install the PCV dirty air tube to the PCV orifice in the right camshaft cover and to the intake manifold.
    
13. Install the PCV fresh air feed tube to the camshaft cover and the water crossover.
    
14. Install the fuel pressure regulator vacuum tube to the fuel pressure regulator and the throttle body.
    
15. Install the brake booster hose to the throttle body.