Can get LIM off

LIM should have two more bolt than the upper intke manifold.
check out this site to see a diagram--I think your is the same.

http://www.2carpros.com/questions/buick-lesabre-2001-buick-lesabre-3800-intake-gasket-replacement

I like your screen name (joke) :-). First thing is why are you replacing the lower intake manifold? Do you see something leaking :-)? You do know about the dealers issued TSB right? The steps below will help you to determine where you made your mistakes.

Removal

Disconnect the negative battery cable.
Remove the fuel injector sight shield (engine cover)
Remove the air cleaner intake duct
Drain cooling system

Remove right spark plug wires from the ignition control module and reposition.

Relieve the fuel pressure.

Remove the fuel tank cap and relieve the fuel system pressure before servicing the fuel system in order to reduce the risk of personal injury. After you relieve the fuel system pressure, a small amount of fuel may be released when servicing the fuel lines, the fuel injection pump, or the connections. In order to reduce the risk of personal injury, cover the fuel system components with a shop towl before disconnecting. This will catch any fuel that may leak out. Place the towel in an approved container when the disconnection is complete.

Remove the fuel rail assembly.

Remove the brake booster hose from the vacuum source manifold.

Remove the exhaust gas recirculation (EGR) valve wiring harness heat shield nut, bolt and the EGR heat shield.

Remove the throttle body support bracket upper bolt.

Disconnect the electrical connectors from the following:

EVAP purge solenoid
Throttle position (T/P) sensor
Idle air control (IAC) valve
Manifold absolute pressure (MAP) sensor
Mass air flow (MAF) sensor
Remove the EVAP purge solenoid vacuum line from the throttle body

Remove the accelerator and the cruise control cables with the bracket from the throttle body.

Remove the upper intake manifold bolts and stud.
Clean the upper intake manifold bolt threads.

Remove the upper intake manifold by lifting the back of the intake and sliding the manifold forward from the throttle body support bracket.

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

If the upper intake manifold is being replaced, remove the following:

Throttle body

Manifold absolute pressure (MAP) sensor
Positive crankcase ventilation (PCV) valve
Vacuum source manifold

Installation

If the manifold was replaced install the following:
Vacuum source manifold

Positive crankcase ventilation (PCV) valve
Manifold absolute pressure (MAP) sensor
Throttle body

Install the upper to lower intake manifold carrier gasket to the upper intake manifold

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.

Install the upper intake manifold.

Apply thread lock compound to the bolt threads before assembly.

Install the upper intake manifold bolts
Tighten the bolts in sequence to 10 N-m (89 lb in)
Install the accelerator and the cruise control cables with the bracket to the throttle body

Install the EVAP purge solenoid vacuum line to the throttle body.

Connect the electrical connectors to the following:
Mass air flow (MAF) sensor
Manifold absolute pressure (MAP) sensor
Idle air control (IAC) valve
Throttle position (T/P) sensor
EVAP purge solenoid

Install the throttle body upper support bracket bolt.
Tighten the bolt to 16 N-m (12 lb in)

Install the EGR valve wiring harness heat shield nut and bolt.

Tighten the nut and the bolt to 10 N-m (89 lb in)

Install the brake booster hose to the vacuum source manifold.

Install the fuel rail assembly.

Install the right spark plug wires to the ignition control module.

Install the air cleaner intake duct.
Install the fuel injector sight shield.
Fill the cooling system.
Connect the negative battery cable.
Inspect for fluid or vacuum leaks.

My LIM is leaking, so I'm just replacing everything (140k) - wife wants the car to last 10 more years - good luck with that!

I just can break it free - I've knocked out most of the gasket on the front side with a scraper and started on the back side. I assume that too much prying can damage the aluminum LIM so I'm being judicious.

Thank You - Thank You- Thank You Bfree. I couldn't see the two bolts in the inner passages because they're filed with oil. Once I got them out it came right off. Whew! I was getting worried... thanks.

Joke,

I really must say that Bfree did a great job in helping you remove the lower intake. He has more than earned a case of Hostess Twinkies for demonstrating his skills and efforts in this matter :-). Now that the old intake is off, have you asked yourself what you’re going to do to prevent the new intake that you are on the verge of installing from failing again? Funny thing is, at this time there's that darn TSB word again :-) :-)

2000-2003 Buick Century

2002-2003 Buick Rendezvous

1996 Chevrolet Lumina APV

1997-2003 Chevrolet Venture

1999-2001 Chevrolet Lumina

1999-2003 Chevrolet Malibu, Monte Carlo

2000-2003 Chevrolet Impala

1996-2003 Oldsmobile Silhouette

1999 Oldsmobile Cutlass

1999-2003 Oldsmobile Alero

1996-1999 Pontiac Trans Sport

1999-2003 Pontiac Grand Am, Montana

2000-2003 Pontiac Grand Prix

2001-2003 Pontiac Aztek

With 3.1L or 3.4L V-6 Engine (VINs J, E - RPOs LG8, LA1)

This bulletin is being revised to change the model Information. Please discard Corporate Bulletin Number 03-06-01-O10A (Section 06 - Engine).

Condition

Some owners may comment on an apparent oil or coolant leak. Additionally, the comments may range from spots on the driveway to having to add fluids.

Cause

Intake manifold may be leaking allowing coolant, oil or both to leak from the engine.

Correction

Install a new design intake manifold gasket. The material used in the gasket has been changed in order to improve the sealing qualities of the gasket. When replacing the gasket, the intake manifold bolts must also be replaced and torqued to a revised specification. The new bolts will come with a pre-applied threadlocker on them.

Notice

An oil leak may result if the vertical bolts are not tightened before the diagonal bolts.

Diagonal bolts may require a crows foot to tighten.

Tighten

Tighten the vertical lower intake manifold bolts (1) to 7 N.m (62 lb in).

Tighten the diagonal lower intake manifold bolts (2) to 7 N.m (62 lb in).

Tighten the vertical lower intake manifold bolts (1) to 13 N.m (115 lb in).

Tighten the diagonal lower intake manifold bolts (2) to 25 N.m (18 lb ft).

Parts Information

Parts are currently available from GMSPO.

THIRD SAMPLE BULLETIN

File In Section: 06 - Engine/Propulsion System

Bulletin No.: 03-06-01-016

Date: May, 2003

TECHNICAL

Subject:

Loss of Coolant, Milky Colored Oil
(Replace Intermediate Intake Gasket)

Models:

2000-2003 Buick LeSabre, Park Avenue, Regal
2000-2003 Chevrolet Impala, Monte Carlo
2000-2003 Pontiac Bonneville
2000-2003 Pontiac Grand Prix
with 3.8L V6 Engine (VIN K - RPO L36)

Built Prior to the VIN Breakpoints shown.

Condition

Some owners may comment on a loss of coolant, coolant odor, having to add coolant or a milky substance on either the oil dipstick or oil fill cap. Additionally, owners may indicate that there are signs of coolant loss left on the ground where the vehicle is normally parked.

Cause

Condition may be due to coolant leaking past intermediate intake or throttle body gaskets.

Correction

Important: The upper intake manifold should not be replaced for a coolant leak condition, unless a rare instance of physical damage is found. Even if the throttle body surface shows a slight warpage, the upper intake should not be replaced unless a drivability concern is noted or a relevant engine DTC, such as a code for an unmetered air leak, is set and the upper intake manifold can clearly be shown as the cause of the concern.

Thoroughly check for any external leaks. If no external leaks are found, then replace the intermediate intake manifold gasket and the throttle body gasket. When changing the throttle body gasket, the nuts that retain the throttle body should be replaced with a new design that improves torque retention. Medium strength thread locker should be applied to the studs before installing the new nuts.

Joke,

Been there done that. As far as upper or lower goes you must replace both manifolds on a your particular Buick. Better take a second look at the posted TSB, because Big Block 409 is right. There are updated manifolds, gaskets, and other parts that you must install. Since you're doing the job, and you have everything apart now, you may as well it right, and put everything back together correctly and with the all the updated parts, so you don't have to do the job over again. Use the links below they will help you.

http://ken-co.com/manifold/default.htm

http://www.dormanproducts.com/

Joke,

Sorry my mistake. I posted the wrong TSB. My database is a mess, and I’m workin on tryin to get it back in order. Part numbers appear below along with other helpful links. Pete’s “Dorman” link is good also. You can go with federal mogul and Dorman or buy everything from GM using the last link below.

Lower Intake -- 24508923
Upper Intake -- 17113136 (includes necessary upper intake plenum gaskets)
Lower Intake Gasket – 12537197

http://www.federalmogul.com/en/AftermarketSolutions/NorthAmerica/SealingSolutions/Products/LeakRepair/Fel-ProManifold/Intake/

http://www.gmpartsdirect.com/