Bolt torque sequence on 1991 jaguar xj6 4.0 intake manifold?

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.

DeVille, Eldorado, Seville 1999-2005

• REMOVAL & INSTALLATION

Cylinder Head

Print

Removal & Installation

Left Side

1. Before servicing the vehicle, refer to the Precautions Section.
2. Drain the cooling system.
3. Properly relieve the fuel system pressure.
4. Remove or disconnect the following:
   
   Negative battery cable Exhaust manifold Alternator Water crossover Intake manifold Valve cover Timing cover Secondary camshaft drive chain Power steering return hose retaining bolt from the cylinder head 3 M6 external drive bolts from the front portion of the cylinder head 10 M11 internal drive cylinder head bolts Cylinder head and gasket.
   
5. Clean the head mating surfaces.

To install:

Fig. Left cylinder head bolt torque sequence-4.6L engine

1. Install the cylinder head with a new gasket. Lubricate the bolts with engine oil prior to installation.
2. Torque the M11 bolts in sequence as follows:
   1. Step 1: 30 ft. lbs. (40 Nm), plus an additional 70 degrees
   2. Step 2: Turn an additional 60 degrees
   3. Step 3: Turn an additional 60 degrees (total 190 degrees)
   
   
3. Torque the M6 bolts to 106 inch lbs. (12 Nm)
4. Install or connect the following:
   
   Power steering return hose retaining bolt to the cylinder head and tighten to 37 ft. lbs. (50 Nm) Secondary camshaft drive chain Timing cover Valve cover Intake manifold Water crossover Exhaust manifold Negative battery cable
   
5. Change the oil and filter.
6. Fill the cooling system.

Right Side

1. Before servicing the vehicle, refer to the Precautions Section.
2. Drain the cooling system.
3. Properly relieve the fuel system pressure.
4. Remove or disconnect the following:
   
   Negative battery cable Exhaust manifold Water crossover Intake manifold Valve cover Timing cover Secondary camshaft drive chain Electrical connector from the Engine Coolant Temperature (ECT) sensor Nut attaching the coil cassette ground wire to the cylinder head Bolt attaching the exhaust crossover pipe to the cylinder head Bolt attaching the right transaxle mount bracket to the cylinder head Bolt attaching the rear transaxle brace to the transaxle Nuts attaching the rear transaxle brace to the cylinder head Rear transaxle brace 3 M6 external drive bolts from the front portion of the cylinder head 10 M11 internal drive cylinder head bolts Cylinder head and gasket
   
5. Clean the head mating surfaces.

To install:

Fig. Right cylinder head bolt torque sequence- 4.6L engine

1. Install the cylinder head with a new gasket. Lubricate the bolts with engine oil prior to installation.
2. Torque the M11 bolts in sequence as follows:
   1. Step 1: 30 ft. lbs. (40 Nm), plus an additional 70 degrees.
   2. Step 2: Turn an additional 60 degrees.
   3. Step 3: Turn an additional 60 degrees (total 190 degrees).
   
   
3. Torque the M6 bolts to 106 inch lbs. (12 Nm).
4. Install or connect the following:
   
   Rear transaxle brace over the studs located at the rear of the right cylinder head Nuts attaching the rear transaxle brace to the cylinder head, loosely Bolts attaching the rear transaxle braces to the transaxle and tighten to 37 ft. lbs. (50 Nm) Nuts attaching the rear transaxle brace to the cylinder head and tighten 37 ft. lbs. (50 Nm) Electrical connector to the ECT sensor Bolt attaching the exhaust crossover pipe to the cylinder head and tighten to 18 ft. lbs. (25 Nm) Nut attaching the coil cassette ground wire to the cylinder head and tighten to 13 ft. lbs. (17 Nm) Secondary camshaft drive chain Timing cover Valve cover Intake manifold Water crossover Exhaust manifold Negative battery cable
   
5. Change the oil and filter.
6. Fill the cooling system.

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).

Head Bolts
Torque sequence --------- ' 6 2 3 7 ' ' 5 1 4 8 ' --------- Step 1: torque in sequence to 33 Ft/Lbs Step 2: turn an additional 90 degrees recheck final torque in sequence *** CAUTION ***engine uses Torque To Yield head bolts (TTY) that permanently stretch during the initial installation.New head bolts must be used when cylinder head is replaced or re-installed to obtain proper torque.Always coat bolt threads with the proper sealant.
The Intake Bolt Torque 10 Foot pounds (Final torque)
Note:to torque bolts & nuts, start in center using crisscross pattern working outward

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Left side front cylinder head



Cylinder head bolt torque sequence-3.4L engine

Cylinder head by aligning it with the dowel pins

New cylinder head bolts coated with a sealant (such as GM 1052080). Torque the bolts in the proper sequence (1-8) to 37 ft. lbs. (50 Nm). Using a torque angle meter turn the bolts 90 degrees in the proper sequence.

Left side exhaust manifold. Torque the bolts to 12 ft. lbs. (16 Nm).

Spark plugs. Torque the plugs 11 ft. lbs. (15 Nm).

Right side rear cylinder head:



Cylinder head bolt torque sequence-3.4L engine

New cylinder head gasket

Cylinder head on top of the gasket and make certain it is lined up properly with the dowel pins

New cylinder head bolts coated with a sealant (such as GM 1052080). Torque the bolts in the proper sequence (1-8) to 37 ft. lbs. (50 Nm). Using a torque angle meter turn the bolts 90 degrees in the proper sequence.

Right side exhaust manifold. Torque the bolts to 12 ft. lbs. (16 Nm).

Spark plugs. Torque the plugs 11 ft. lbs. (15 Nm).

Spark plug wires

Exhaust crossover pipe. Torque the fastener to 18 ft. lbs. (25 Nm).

Valve rocker arms and pushrods. Torque the fastener to 89 inch lbs. (10 Nm). Using a torque angle meter torque the fastener an additional 30 degrees.

Lower intake manifold. Torque the bolts to 115 inch lbs. (13 Nm).

Upper intake manifold. Torque the bolts to 18 ft. lbs. (25 Nm).

Fig. Intake manifold bolt torque sequence 2.7L engine

Upper intake manifold with a new gasket on the lower intake manifold and torque the bolts, in sequence, to: 105 inch lbs. (12 Nm)

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Intake manifold using new gaskets. Torque the bolts, in sequence, to 105 inch lbs. (12 Nm)...



Fig. Intake manifold torque sequence-3.7 & 4.7L engines


Hope this help (remember comment and rated this).

Please don't forget to rate. Thank you:

Left side front cylinder head



Cylinder head bolt torque sequence—3.4L engine

Cylinder head by aligning it with the dowel pins

New cylinder head bolts coated with a sealant (such as GM 1052080). Torque the bolts in the proper sequence (1-8) to 37 ft. lbs. (50 Nm). Using a torque angle meter turn the bolts 90 degrees in the proper sequence.

Left side exhaust manifold. Torque the bolts to 12 ft. lbs. (16 Nm).

Spark plugs. Torque the plugs 11 ft. lbs. (15 Nm).

Right side rear cylinder head:



Cylinder head bolt torque sequence—3.4L engine

New cylinder head gasket

Cylinder head on top of the gasket and make certain it is lined up properly with the dowel pins

New cylinder head bolts coated with a sealant (such as GM 1052080). Torque the bolts in the proper sequence (1-8) to 37 ft. lbs. (50 Nm). Using a torque angle meter turn the bolts 90 degrees in the proper sequence.

Right side exhaust manifold. Torque the bolts to 12 ft. lbs. (16 Nm).

Spark plugs. Torque the plugs 11 ft. lbs. (15 Nm).

Spark plug wires

Exhaust crossover pipe. Torque the fastener to 18 ft. lbs. (25 Nm).

Valve rocker arms and pushrods. Torque the fastener to 89 inch lbs. (10 Nm). Using a torque angle meter torque the fastener an additional 30 degrees.

Lower intake manifold. Torque the bolts to 115 inch lbs. (13 Nm).

Upper intake manifold. Torque the bolts to 18 ft. lbs. (25 Nm).

3.8L Engine

NOTE The 3.8L (VIN K) non-supercharged engine uses a two-piece intake manifold consisting of an upper air plenum which mounts the throttle body and a lower intake manifold assembly which houses the fuel injectors. The 3.8L (VIN 1) supercharged engine uses a similar lower intake manifold. The supercharger serves as the upper manifold.
Lower Manifold

NOTE Two bolts which fasten the lower intake manifold to the cylinder head are accessible only after the upper intake manifold is removed. These bolts are located in the right front and left rear corners of the lower intake manifold. Remove the upper intake manifold to service the lower intake.
The 3.8L (VIN 1) supercharged engine uses a manifold similar to the 3.8L (VIN K), but the supercharger serves as the upper manifold.

1. Disconnect the negative battery cable.
2. On 3.8L (VIN 1) engines, remove the supercharger assembly. Please see the procedure in this section.
3. Remove the upper intake manifold using the procedure above.
4. Remove the EGR outlet pipe from the intake manifold.
5. Detach the engine coolant temperature sensor wiring harness from the sensor.
6. Remove the lower intake manifold bolts and carefully lift off the manifold.

To install:


Fig. Lower intake manifold bolt torque sequence-3.8L (VIN K) engine

1. Clean all parts well with degreaser, especially the gasket seal surfaces on the upper and lower manifold pieces and between the lower manifold and the cylinder heads..
2. Install new gaskets to the cylinder heads and new seals to the engine block. Carefully lower the manifold into place. Apply thread-locking compound to the bolt threads. Make sure to install the two hidden bolts in the lower intake manifold. Hand start all bolts, then torque evenly to 11 ft. lbs. (15 Nm). Follow the toque sequence, starting in the center, then working outwards in a circle.
3. Install the remaining components in the reverse order of the removal process.

Upper Intake Manifold (Plenum)

1. Disconnect the negative battery cable.
2. On 3.8L (VIN 1) engines, remove the supercharger assembly. Please see the procedure in this section.
3. Tag for identification, then remove the right side spark plug wires.
4. Disconnect the ignition wires from the fuel rail.
5. Remove the fuel rail. Please see Section 5.
6. Remove the cable bracket from the intake manifold.
7. Remove the throttle body.

NOTE Two bolts which fasten the lower intake manifold to the cylinder head are accessible are accessible only after the upper intake manifold is removed. These bolts are located in the right front and left rear corners of the lower intake manifold.

1. Remove the upper intake manifold bolts and carefully lift the upper intake manifold from the engine.

Fig. Upper intake manifold and bolt torque sequence-3.8L (VIN K) engine
To install:

1. Clean all parts well with degreaser, especially the gasket seal surfaces on the upper and lower manifold pieces.
2. Install new gaskets to the cylinder heads and new seals to the engine block. Carefully lower the manifold into place. Make sure to install the two hidden bolts in the lower intake manifold. Hand start all bolts, then torque evenly to 89 inch lbs. (10 Nm). Follow the torque sequence, starting in the center, then working outwards in a circle.
3. Install the remaining components in the reverse order of the removal process.