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gmtech1967
gmtech1967, Pontiac Technician
Category: Pontiac
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Experience:  15 years general exp. 5 years GM certified tech.
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Pontiac gran prix gt: how do i replace plenum on 1999 gran

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how do i replace plenum on 1999 gran prix?
Welcome to Just Answers,
I can provide you with the upper plenum replacement procedure.
super charged or non?
Customer: replied 4 years ago.
none
Here is the non super charged procedure;

If you need any other information on this repair please ask me.



1. Disconnect the battery ground (negative) cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Starting and Charging.
2. Carefully remove the throttle body air inlet duct.
3. Drain the engine coolant from the cooling system. Refer to Draining and Filling Cooling System in Engine Cooling.
4. Remove the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement (L36 (VIN K)).
5. Remove the right spark plug wires. Refer to Spark Plug Wire Harness Replacement in Starting and Charging.
6. Disconnect the evaporative emissions canister purge solenoid valve wiring harness connector.
7. Relieve the fuel pressure. Refer to Fuel Pressure Relief Procedure in Powertrain Management.
8. Remove the fuel rail. Refer to Fuel Rail Assembly Replacement (Fuel Rail Assembly Replacement) in Powertrain Management.
9. Remove the brake booster hose from the vacuum source manifold in the upper intake manifold. Refer to Vacuum Brake Booster Hose Replacement in Hydraulic Brakes.
10. Remove the EGR shield.

graphic


11. Remove the throttle body support bracket.

graphic

12. Disconnect the MAP sensor electrical connector. Refer to MAP Sensor Replacement (VIN K) in Powertrain Management.
13. Remove the upper intake manifold bolts.
14. Clean the upper intake manifold bolt threads.
15. Remove the upper intake manifold.

graphic

16. Remove the upper-to-lower intake manifold carrier gasket from the upper intake manifold.

graphic

17. If the upper intake manifold is being replaced, remove the throttle body. Refer to Throttle Body Assembly Replacement in Powertrain Management.

18. If the upper intake manifold is being replaced, remove the vacuum source manifold.

graphic

Installation Procedure


1. If the upper intake manifold is being replaced, install the vacuum source manifold.
2. If the upper intake manifold is being replaced, install the throttle body. Refer to Throttle Body Assembly Replacement in Powertrain Management.

3. Install the upper-to-lower intake manifold carrier gasket to the upper intake manifold.

4. Carefully place the upper intake manifold onto the lower intake manifold. Ensure that the alignment pins in the upper intake manifold align with the holes in the lower intake manifold.
5. Install the upper intake manifold.
6. Apply thread lock compound GM P/N 12345382 or equivalent, to the bolt threads before assembly.

Notice: Refer to Fastener Notice in Service Precautions.

7. Install the upper intake manifold bolts (1-10).

graphic
^ Tighten the upper intake manifold bolts in sequence to 10 Nm (89 inch lbs.).
8. Connect the MAP sensor electrical connector. Refer to MAP Sensor Replacement (VIN K) in Powertrain Management.

9. Install the throttle body support bracket.
10. finalist the throttle body support bracket bolts.
^ Tighten the throttle body support bracket bolts to 10 Nm (89 inch lbs.).

11. Install the EGR shield.
12. Install the brake booster hose to the vacuum source manifold in the upper intake manifold. Refer to Vacuum Brake Booster Hose Replacement in Hydraulic Brakes.
13. Install the fuel rail. Refer to Fuel Rail Assembly Replacement (Fuel Rail Assembly Replacement) in Powertrain Management.
14. Connect the evaporative emissions canister purge solenoid valve wiring harness connector.
15. Install the right spark plug wires. Refer to Spark Plug Wire Harness Replacement in Starting and Charging.
16. Install the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement (L36 (VIN K)).
17. Refill the cooling system with engine coolant. Refer to Draining and Filling Cooling System in Engine Cooling.
18. Carefully install the throttle body air inlet duct.
19. Connect the battery ground (negative) cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Starting and Charging.
20. Inspect for the proper fluid levels.
21. Inspect for fluid or vacuum leaks.
There was a GM service bulletin on these engines. once the lower intake is cleaned up you are supposed to inspect the area around the egr tube i will post and image of the area to check graphic

if the area is degraded or corroded away you are to replace the lower intake manifold too.



TECHNICAL

Subject:
Engine Coolant Consumption or Coolant Leak (Inspect For Material Degradation/Replace Intake Manifolds)

Models:
1995-1997 Buick Riviera
1995-1999 Buick LeSabre, Park Avenue
1996-1999 Buick Regal
1998-1999 Chevrolet Lumina, Monte Carlo
1995-1996 Oldsmobile Ninety-Eight
1995-1999 Oldsmobile Eighty-Eight
1998-1999 Oldsmobile Intrigue
1995-1999 Pontiac Bonneville
1997-1999 Pontiac Grand Prix

with 3.8L Engine (VIN K - RPO L36)

Supercede:

This bulletin is being revised to add to the 1999 model year. Please discard Corporate Bulletin Number 01-06-01-007B (Section 06 - Engine).

Condition

Some customers may comment on excessive engine coolant consumption, or an engine coolant leak near or under the throttle body area of the upper intake manifold.

Cause

Upper intake manifold composite material may degrade around the EGR stove pipe and could result in an internal or external coolant leak.

Correction

Follow the upper intake manifold removal instructions found in the Engine Unit Repair Section of the Service Information Manual.


Refer to the arrow in the illustration of the upper intake manifold above. Inspect the inner diameter of the EGR passage for signs of material degradation. Degradation will appear as "pitting" of the composite material in the EGR port passage.

If degradation of upper intake manifold composite material is found, replace the lower and upper intake manifolds with the following part numbers:

Gasket Kit, Upper Intake Manifold - 89017554

Manifold Kit, Upper Intake - 89017272

Gasket, Lower Intake Manifold - 89017400

Manifold, Lower Intake - 24508923

Follow the lower and upper intake manifold installation instructions found in the Engine Unit Repair Section of the appropriate Service Manual.

If degradation is not apparent, skip to Step 7.

Verify the repair.

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