So my trunk wont stay open when i pop it up. how do i fix that? Its a 1998 Bonneville!

*** Moved from Chat ~ Kevin ***

Sounds like a broken spring. Check for that first. If broken, find a salvage yard and pull one to install in your car.

how do i replace the spring exactlly?

Not something I've ever done. Should be some brackets holding it in place.

I replaced the spring on my 92 a number of years ago. It is not a spring, but a metal rod that fits across the width of the trunk lid. There may be two rods. I replaced one of them. Take a look in the trunk under the rear deck. Look for a broken rod. Pay close attention to how it is situated so you can put the new one in correctly. Hopfully that will be the issue.

Its a real buger too. I replaced one on my 96 last yr. I can't remember exactly how I did it but I do remember taking some bolts loose to get some wiggle room.

I think you can also change the tension on those metal rods by moving them one notch. I'll have to take a peek at mine when I take off for work. I have removed them from my 95 before, but it'* been awhile. I think you need like a socket to slip over the end of the rod to aid in moving the ends. I'll keep you posted.

Torque Rod Replacement - Rear Compartment Lid
Removal Procedure
Tools Required
J 39384-3 Torque Rod Retaining Pin
J 39384-10 Torque Rod Adjustment Bar




Remove the trim panel between the rear seat and the rear window.
Remove the retainer clip from the torque rod (2) at the hinge (1).
From inside the vehicle, loosen, but do NOT remove, the 2 hinge retaining bolts.
Support the rear compartment lid.
Complete the following steps in order to relieve the tension on the torque rod (2):
Insert the J 39384-3 in the hinge (1).
Insert the J 39384-10 over the end of the torque rod (2).
Remove the torque rod (2) from the adjusting notches.
Installation Procedure
Tools Required
J 39384-3 Torque Rod Retaining Pin
J 39384-10 Torque Rod Adjustment Bar




Install the torque rod (2) between the hinge (1) and the shelf.

Important
Properly seat the torque rod between the rear shelf and the hinge assembly.


Slide the torque rod (2) into the hinge (1). Secure the rod with the retainer.
Open and close the rear compartment lid in order to confirm that the torque rod (2) is seated properly.

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.


Install the hinge retaining bolts. Tighten
Tighten the bolts to 18 N·m (13 lb ft).

Insert the torque rod into the adjustment notch:
Insert the J 39384-3 in the hinge.
Insert the J 39384-10 over the end of the torque rod.
Adjust the rear compartment lid to the desired tension. Refer to Compartment Lid Adjustment - Rear .
Install the trim panel between the rear seat and the rear window.

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Document ID# 468479
1998 Pontiac Bonneville

Compartment Lid Adjustment - Rear
Torque Rod Adjustment
Tools Required
J 39384-3 Torque Rod Retaining Pin
J 39384-10 Torque Rod Adjustment Bar




Support the rear compartment lid.
Insert the J 39384-3 (3) into the hinge (1).
Insert the J 39384-10 (4) over the end of the torque rod (2).
Adjust the torque rod to 1 of 3 positions for desired tension. In order to decrease the amount of effort needed to raise the lid, reposition the end of the torque rod in a notch closer to the rear of the vehicle.
Fore/Aft Adjustment and Flushness





Important
Verify that the rubber overslam bumpers are completely screwed into the rear compartment lid. Do NOT use the overslam bumpers for adjustment.


With the lid (2) in the closed position, verify the fore/aft adjustment of the rear compartment lid at the rear corners of the lid. Verify the flushness of the lid to the quarters. If adjustment is necessary, loosen the bolts (1) that connect the rear compartment lid to the hinge. Adjust the lid.

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.


Tighten the hinge bolts (1). Tighten
Tighten the bolts to 25 N·m (18 lb ft).





If the rear compartment lid is not flush at the rear, loosen the inner latch striker mounting nut (2). Close the rear compartment lid.
From beneath the rear bumper fascia, mark the vertical location of the outer latch striker mounting nuts (2).
Loosen the outer latch striker mounting nuts.
The latch striker (1) should move upward.
If the latch striker does not move, the striker is probably at the top of its adjustment range. Make an adjustment to the latch assembly.
Verify that the rear compartment lid remains flush to the quarter panels. Tighten the outer latch striker mounting nuts (2). Tighten
Tighten the nuts to 9 N·m (80 lb in).

Tighten the inner latch striker mounting nut. Tighten
Tighten the nut to 9 N·m (80 lb in).

Lid to Quarter Gaps
With the lid in the closed position, inspect the gaps between the rear compartment lid and the quarter panel. The gaps should be 3-4 mm (3/32-1/8 in), at the front and at the rear corners of the lid.
If the proper gaps are present, you may need to adjust the latch striker or the latch.
If the proper gaps are not present, complete the following steps in order to adjust the rear compartment lid.
Remove the rear shelf speaker covers.
Loosen the lid hinge to the rear shelf attachments.
Position the rear compartment lid in the opening in order to obtain the proper gaps.
Loosen the latch mounting bolts.
With an assistant in the rear compartment, gently close the lid until the latch contacts the latch striker. While holding the lid down, have the assistant snug the latch mounting bolts.
Raise the rear compartment lid.
Tighten the latch mounting bolts. Tighten
Tighten the bolts to 10.5 N·m (93 lb in).

Tighten the bolts that connect the hinge to the shelf. Tighten
Tighten the bolts to 18 N·m (13 lb ft).

Verify the proper operation of the rear compartment lid.
Verify the gaps between the rear compartment lid and the quarter panel.

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Document ID# 468473
1998 Pontiac Bonneville

I have some diagrams if you would like them i can get them for you