Intake manifold bolt pattern 1999 jimmy 4 by 4 i replaced the intake gasket my son did not use a bolt pattern o a tork wrench it leaks at the back under side

First, without a picture to guide, orientation of the bolt torque pattern. Looking back toward the engine from the front; Forward refers to the bolt position toward the front of the car / aft is toward the cars rear:

1st bolt is forward, 3rd from the left
2nd is aft, 3rd from left
3rd is forward, 2nd from left
4th is aft, 2nd from left
5th is forward, 1st on the right
6th is aft, 1st on right
7th is forward, 1st on left
8th is aft, 1st on the left

The following is from the GM 2005 Chevy Equinox service manual;

Notice
Maximum gasket performance is achieved when using new fasteners, which contain a thread locking patch. If the fasteners are not replaced, a thread locking chemical must be applied to the fastener threads. Failure to replace the fasteners or use thread locking chemical MAY reduce gasket sealing capability.

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 to avoid damage to fasteners and systems.

IMPORTANT: All lower intake manifold bolts need to be cleaned, free of any foreign material, and reused - only if new bolts are unavailable. Use GM P/N 12345382 (Canadian P/N 10953489) or equivalent and apply to the old intake manifold bolt threads.

IMPORTANT: Manufacturer recommends the center bolts be fully torqued before the diagonal bolts to assure proper seal ability.

IMPORTANT: Lower intake manifold bolts in positions 6 and 7 should be torqued to specification using a crows foot type tool.

Install the lower intake manifold bolts.
a. Tighten the lower intake manifold bolts (1, 2, 3, 4) in sequence to 7 N-m (62 lb in) on the first pass.
b. Tighten the lower intake manifold bolts (5, 6, 7, 8) in sequence to 13 N-m (115 lb in) on the first pass.
c. Tighten the lower intake manifold bolts (1, 2, 3, 4) in sequence to 13 N-m (115 lb in) on the final pass.
d. Tighten the lower intake manifold bolts (5, 6, 7, 8) in sequence to 25 N-m (18 lb ft) on the final pass.

Instructions

1. Removal

Unscrew the bolt that holds the negative connection to the Impala's battery. Set this bolt aside for later use.

Remove the engine cover to access the intake manifold and manifold gasket. Disconnect the throttle body inlet duct from the engine.

Twist off the radiator cap to allow draining of the coolant to flow more smoothly. Place an empty container beneath the radiator's drain plug, and remove this plug. Allow all of the engine coolant to drain into the empty container. Replace the drain plug once you are finished.

Tag all of the electrical wiring and hoses before removing so that reconnection is precise to factory settings. Remove these parts, individually, from the intake manifold.

Loosen the bolts that hold the intake manifold to the Impala's engine block. Lift the intake manifold from the block once all bolts have been completely removed.

Use the flat-head screwdriver to pry the old intake manifold gasket from the engine block. Discard this part once you have removed it.

Clean the engine block thoroughly with the engine degreaser and linen cloth. If necessary, use a gasket scraper to remove excess buildup and grime.

2. Installation

• Coat the top and bottom of the new intake manifold gasket with a chemical sealer so that it bonds to the engine block securely. Position this new manifold gasket so that it lines up perfectly with the cylinder ports of the Impala's engine block.

Place the old intake manifold on top of the newly-installed manifold gasket until it aligns with all of the holes of the cylinder flanges and manifold gasket.

Attach all of the bolts with your hand to the manifold. Once all bolts have been positioned, use a torque wrench and apply 15 foot-pounds of pressure to the bolts to secure the manifold into place.

Reconnect all of the necessary hoses and electrical wiring to the intake. Pour the engine coolant back into the radiator.

Reattach the engine cover on top of the intake manifold and engine block. Start the Impala's engine and check for any leaks around the new intake manifold gasket.

I had this happen to me the first time I replaced my intake manifold gaskets. It was hard to install the intake and gasket moved just enough and I had a coolant leak. Removed manifold and installed new gaskets and problem was solved. Good Luck.

Hello,

Here is a detailed summary on the procedure of how to replace the intake manifold gasket on a 1996 gmc jimmy;
REMOVING THE UPPER INTAKE MANIFOLD(PLENUM)
STEP 1 Disconnect Battery (may not be absolutely necessary, but a good practice to avoid shorting a positive wire to ground).


STEP 2 Remove serpentine belt.

STEP 3 Drain the coolant.

STEP 4 Remove air cleaner ducting and disconnect wires.

STEP 5 Disconnect throttle linkage and bracket.

STEP 6 Disconnect cruise control cable.

STEP 7 Remove brake booster vacuum hose at manifold.

STEP 8 Remove PCV hose.

STEP 9 Remove ignition coil and bracket.

STEP 1O Remove purge solenoid and bracket.

STEP 11 Relieve fuel pressure at test port.

STEP 12 Remove fuel lines and bracket.

STEP 13 Remove upper intake manifold.

REMOVING THE LOWER INTAKE MANIFOLD
STEP 1 Remove the distributor and label the spark plug wires.

STEP 2 Remove heater hoses and bypass hose.

STEP 3 Remove upper radiator hose.


STEP 4 Remove EGR valve?

STEP 5 Remove sensors and bracket on right side.

STEP 6 Remove EGR tube, clamp and bolt.

STEP 7 Remove PCV valve (and replace).

STEP 8 Unbolt A/C compressor and move it aside.

STEP 9 Loosen compressor bracket and slide forward, but do not remove it.

STEP 10 Remove alternator bracket bolt (or remove alternator and set aside)

STEP 11 Unplug all vacuum lines from intake manifold.


STEP 12 Unplug all electrical connectors from manifold.

STEP 13 Take note of the intake manifold bolts and mark the location of the bolts.


STEP 14 Remove intake manifold bolts, and manifold.

STEP 15 Clean mating surfaces

THE MAIN INSTALLATION
STEP1 Set the new gaskets in place and apply silicone to flat areas on front and rear of engine block.

STEP2 Apply thread locking compound to manifold bolts.

STEP 3 Install the manifold and tighten bolts to 35 ft-lbs, in proper sequence.

STEP4 Install the distributor.

STEP5 Install the upper intake manifold.



The remaining installation procedures are basically the reverse of removal.


Have a nice day.

Position The Intake Manifold Gasket On The Engine.Dowels May Be Provided To Hold The Gasket In Place During Manifold Installation.. The Use Of Silicone Sealer Is Required. Especially Where The Front And The Rear Seals Meet The Side Gaskets On V-type Engines. Installing An Intake Manifold On V-type Engines Can Be Difficult. It Is Critical That You Use Sealer Properly On The Engine To Prevent Vacuum,Coolant, And Oil Leaks.

Start All The Fasteners By Hand Before Tightening. This Will Aid In Bolt Hold Alignment. Then Torque The Intake Manifold Fasteners To Specifications. Use The Specific Torque Pattern Given In The Service Manual.. Basically The Pattern Will Be A Crisscross Pattern

answer , very carefully ...

drain coolant , remove and mark all vacuum lines , make a schematic to diagram your hose routing, disconnect and plug all fuel lines, remove distributor and mark location of rotor, disconnect battery, remove any necessary cables, brackets and or accesseries, remove intake mounting bolts, note length of bolts and reference location, pry up on intake , remove intake, scrape old gasket off , must be very clean to reinstall new gasket or you will cause a leak..

it could but- check passenger side front where heater core line go into manifold right behind alternator the hose line is connected by a press clip into an alloy fitting this fitting gets eaten away by anti freeze and hose angle pulls back on fitting the part is $18 at dealer and is screwed into manifold use caution if ur r going to replace at very edge of aluminum manifold---and check ur water pump bolts the 2 longer ones should have a lock sealant on them they bolt in thru a water jacket

You unbolt the intake manifold, remove the old gasket, install a new gasket, and bolt the maniforld back on.

You may have to remove sensors or hoses that block removal of the intake manifold.

you'll need a torque wrench when you bolt the manifold back on

I guess the burning question is , where is the coolant going.
Is this a 4.3 engine? How many miles does the vehicle have?
Has the intake gasket been changed?
I'm guessing a can of "Bars Leak" may cure your problem.
Let me know.
Regards,

i usually just tighten them hand tight using the cross pattern there is a tourque spec it is 44inch lbs i belive but never had a problem tighting them like i explained