Tightening sequence diagram for a 97 buick lesabre intake manifold?

Question edited for clarity and spelling of the model.
Question moved to model category.

For the lower intake:
Step 1 - Tighten down to 62in/lbs (not ft/lbs) Center bolts first then outer bolts - Bring all bolts to finger tight then tighten in 1/4 turn increments till proper torque is achieved.
Step 2 - tighten down to 115in/lbs (not ft/lbs) Center bolts first then outer bolts - Tighten in 1/4 turn increments till proper torque is achieved.

For upper intake
Tighten to 18ft/lbs (not in/lbs) starting from the center and working out in a criss-cross pattern - Bring all bolts to finger tight then tighten in 1/4 turn increments till proper torque is achieved.

https://www.google.com/search?q=buick+lesabre+3.8+intake+manifold+torque+specs

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either the intake manifold or head--whichever is cracked

1997 2005 Buick LeSabre Intake Manifold Gasket Replacement Buick Intake... you can download the pdf file & your problem will be solved:)

1997 2005 Buick LeSabre Intake Manifold Gasket Replacement Buick Intake... you can download the pdf file & I hope your problem will be solved:)

Tightening sequence would be to tighten from the center most bolts to the outer most bolts.
Intake Upper Bolts = 18 lb.ft.
Intake Lower Bolts = 10 lb.ft.
Exhaust Manifold Nut = 12 lb.ft
Exhaust Manifold pipe = 22 lb.ft.
Exhaust Manifold Heat Shield = 18 lb.in.
Rocker Arm Torque Nuts = 18 lb.ft.

Hope this helped you ?? if you need more info, get back to me.....

start in the center working in an expanding square pattern crossing over the manifold on the first 2 bolts. tighten in 3 steps. these are low torque fasteners, don't over tighten & use locktite.
If reusing the fasteners, apply threadlock GM P/N 12345382 or equivalent to the threads of the lower intake manifold bolts.
Install the lower intake manifold bolts.

Notice: Proper lower intake manifold fastener tightening sequence and torque is critical. Always follow the tightening sequence, and torque the intake manifold bolts using the 3 step method. Failing to do so may distort the crankshaft bearing bore alignment and cause damage to the crankshaft bearings.

Tighten the lower intake manifold bolts.

from front of engine tighten 2 bolt back left side, then 3rd bolt back right side, then 3 bolt back left side, then 2nd bolt back right side, then back bolt left side, back bolt right side, then front bolt left side, then front bolt right side

Tighten the bolts on the first pass in sequence (1-8) to 3 N·m (27 lb in).
Tighten the bolts on the second pass in sequence (1-8) to 12 N·m (106 lb in).
Tighten the bolts on the final pass in sequence (1-8) to 15 N·m (11 lb ft).

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.
    

Here is the removal procedure, and the procedure is the same for both the V-6 and the V-8 Vortec engines. Also, be certain to put engine oil on the "o"-ring seal for the fuel injector assembly before installing the upper intake. Let me know if you require any further assistance.

REMOVAL:

1. Disconnect the battery negative cable assembly from the battery negative terminal.

2. Remove the air cleaner assembly.

3. Remove the wiring harness connectors and the brackets and move aside.

4. Remove the throttle cable and the bracket from the upper intake manifold.

5. Remove the cruise control cable, (if equipped).

6. Remove the fuel lines from the intake to the rear of the block.

7. Remove the ignition coil and the bracket.

8. Remove the upper intake manifold.

INSTALLATION:

1. Install the upper intake manifold gasket.

2. Install the upper intake manifold. Use care not to pinch the injector lines between the upper and lower intake manifolds.

3. Install the upper intake manifold bolts. Note the marks made at disassembly for proper stud location. Install the two corner studs first in order to help align the two halves. NOTE: Other than the two torque passes listed below, the OE Manufacturer did NOT address or supply a bolt tightening sequence for the upper Intake Manifold for this model year, or other model years where this 2 piece manifold setup is used. A "Play It Safe" final tightening sequence would be to tighten from the center most bolts to the outer most bolts.

4. Tighten the bolts in two steps: a. Tighten the bolts on the first sequence to 5 Nm (44 inch lbs.). b. Tighten the bolts on the final sequence to 10 Nm (88 inch lbs.).

5. Install the purge solenoid and bracket.

6. Install the ignition coil and bracket.

7. Install the PCV hose et the upper intake manifold.

8. Install the fuel lines from the intake at the rear of the block.

9. Install the cruise control cable (if equipped).

10. Install the throttle cable and bracket from the upper intake manifold.

11. Install the wiring harness connectors and brackets.

12. Install the air cleaner assembly.

13. Connect the battery negative cable assembly to the battery negative terminal. - Tighten the bolt to 15 Nm (11 ft. lbs.).

only if it is the same displacement(aka 3.8Litre) and even then you shoul use the intake manifold from the 97 with all the correct sensors and wiring.computer programs are not the same between the 2 cars even if same manufacturer. or change computer and wire harness from the Riv the the LeSabre.

these cars have issues with coolent getting into the intake... headgaskets are not one of the issues . check plugs for coolent. upper plastic intake has coolent flow in to chambers if u will, and over time they get micro cracks and brittle ...lower intake manifold gaskets are plastic also. ..cyl. heads are cast iron not alluminum . lower intake manifold is alluminum and upper intake is plastic .. on my lesabre a plastic 90 degree elbow connected to the lower intake manifold to the heater hose housing. the belt tensioner is connected to this housing im refering to. not saying for sure, but if it is this is usually why...