Infiniti I35 2002-2004 Exhaust System Bolt Torque Specifications & Gasket Sealing
Infiniti I35 2002-2004

Infiniti I35 2002-2004 Exhaust System Bolt Torque Specifications

Detailed torque specifications for the exhaust bolts of the 2002-2004 Infiniti I35, including manifold, downpipe, and flange bolts. Essential for proper installation and maintenance.

Updated

Important Information

Safety guidelines and reference information for proper torque application

Quick Reference Guide

ft-lbs → Nm
× 1.356
ft-lbs → kg-m
× 0.138
Nm → ft-lbs
× 0.738
in-lbs → ft-lbs
× 0.083

Common Torque Patterns

Star Pattern

Used for wheels and other circular bolt patterns

Star Pattern torque pattern diagram showing proper bolt tightening sequence
Cross Pattern

Used for gaskets and cover plates

Cross Pattern torque pattern diagram showing proper bolt tightening sequence
Sequential Pattern

Used for head bolts and other critical components

Sequential Pattern torque pattern diagram showing proper bolt tightening sequence

Common Mistakes to Avoid

Over-tightening

Exceeding the specified torque value can stretch or break fasteners, damage threads, or crack components.

Prevention:

Always use a calibrated torque wrench and follow specifications exactly.

Incorrect Torque Sequence

Tightening bolts in the wrong order can cause uneven pressure distribution and potential leaks or damage.

Prevention:

Follow the manufacturer's specified torque sequence pattern.

Dirty Threads

Dirt, rust, or old thread locker can affect torque readings and proper fastener tension.

Prevention:

Clean and inspect all threads before assembly. Use new thread locker if specified.

Reusing TTY Bolts

Torque-to-yield bolts are designed to stretch and must not be reused.

Prevention:

Always replace TTY bolts with new ones. They are single-use only.

Dry vs. Lubricated

Not accounting for whether torque specs are for dry or lubricated fasteners can lead to incorrect tension.

Prevention:

Check if specs are for dry or lubricated threads. Use specified lubricant when required.

Recommended Tools

Torque Wrench (1/4" Drive)

Range: 2-25 ft-lbs
Small fasteners, delicate components

Torque Wrench (3/8" Drive)

Range: 10-100 ft-lbs
Most common automotive fasteners

Torque Wrench (1/2" Drive)

Range: 30-250 ft-lbs
Large fasteners, wheels

Angle Gauge

Torque-to-yield (TTY) bolts

Torque Wrench Care

  • Calibrate annually or after 5,000 clicks
  • Store at lowest setting
  • Keep clean and lubricated

Search Specifications

Search by component name, bolt size, or description

Torque Calculator

Convert between different torque units

Exhaust Manifold Headers

This subsystem includes components that connect the exhaust manifold or headers to the cylinder head and exhaust pipe, ensuring proper sealing and alignment of the exhaust system to the engine.

1

Exhaust Manifold/Headers to Cylinder Head Bolts

M10 x 1.25
Torque Value
36.5 ft-lbs (49.5 N·m)
Important Notes
Torque value is an average of the provided range (33-40 ft-lbs).
2

Exhaust Pipe to Exhaust Manifold/Headers Bolts

M10 x 1.25
Torque Value
36.5 ft-lbs (49.5 N·m)
Important Notes
Torque value is an average of the provided range (33-40 ft-lbs).

Catalytic Converter

This subsystem includes components that connect the catalytic converter to the exhaust pipe, ensuring proper sealing and emissions control.

1

Catalytic Converter to Exhaust Pipe Bolts

M8 x 1.25
Torque Value
25.5 ft-lbs (34.5 N·m)
Important Notes
Torque value is an average of the provided range (22-29 ft-lbs).

Muffler

This subsystem includes components that connect the muffler to the exhaust pipe, ensuring proper alignment and sealing to prevent noise leaks.

1

Muffler to Exhaust Pipe Bolts

M8 x 1.25
Torque Value
25.5 ft-lbs (34.5 N·m)
Important Notes
Torque value is an average of the provided range (22-29 ft-lbs).

Exhaust Pipe Clamps

This subsystem includes components that secure exhaust pipe clamps, ensuring the pipes are firmly connected and preventing vibration-induced leaks or misalignment.

1

Exhaust Pipe Clamp Bolts

M8 x 1.25
Torque Value
25.5 ft-lbs (34.5 N·m)
Important Notes
Torque value is an average of the provided range (22-29 ft-lbs).

Heat Shields

This subsystem includes components that secure heat shields around the exhaust system, protecting surrounding components from heat damage and ensuring proper thermal management.

1

Exhaust Heat Shield Bolts

M6 x 1.0
Torque Value
16 ft-lbs (22 N·m)
Important Notes
Torque value is an average of the provided range (14-18 ft-lbs).

Support Brackets

This subsystem includes components that secure support brackets, which hold the exhaust system in place, preventing vibration and ensuring structural stability of the exhaust components.

1

Exhaust System Support Bracket Bolts

M8 x 1.25
Torque Value
25.5 ft-lbs (34.5 N·m)
Important Notes
Torque value is an average of the provided range (22-29 ft-lbs).

Troubleshooting Guide

Common issues, diagnostic steps, and prevention guidelines

Common Issues

Bolt stretching, stripped threads, uneven torque patterns

Loose Components

Symptoms:
  • Rattling or vibration noises
  • Visible movement in components
  • Uneven panel gaps
Solutions:
  • Clean threads and mounting surfaces
  • Replace damaged fasteners
  • Apply proper torque in sequence
  • Use thread locker if specified

Stripped Fasteners

Symptoms:
  • Unable to achieve proper torque
  • Fastener spins freely
  • Visible thread damage
Solutions:
  • Use thread repair kit if appropriate
  • Install thread insert (HeliCoil)
  • Replace component if threaded hole is damaged
  • Upgrade to higher grade fastener if recommended

Overtightened Components

Symptoms:
  • Cracked or deformed parts
  • Broken fasteners
  • Compressed gaskets or seals
Solutions:
  • Replace damaged components
  • Use new fasteners
  • Follow proper torque sequence
  • Verify correct torque specifications

Diagnostic Steps

Visual inspection, torque verification, thread assessment

1

Visual Inspection

Inspect the affected area for any visible signs of damage or wear

  • Check for cracks or deformation
  • Look for signs of excessive wear
  • Verify proper fastener installation
2

Torque Verification

Verify the torque applied to the fasteners

  • Check the torque wrench calibration
  • Verify the torque specification
  • Compare the applied torque to the specification
3

Thread Assessment

Assess the condition of the threads

  • Check for signs of thread damage
  • Verify the thread type and size
  • Check for proper thread engagement

Prevention Guidelines

Best practices, maintenance tips, tool care

Best Practices

  • Always follow the recommended torque specification
  • Use the correct type and size of fasteners
  • Verify the torque wrench calibration regularly

Maintenance Tips

  • Regularly inspect the affected area for signs of wear or damage
  • Replace damaged or worn-out components promptly
  • Keep the work area clean and organized

Tool Care

  • Regularly clean and maintain the torque wrench
  • Store the torque wrench in a dry and secure location
  • Verify the torque wrench calibration before each use

Frequently Asked Questions

Find answers to common questions about torque specifications

Q1

What is the torque specification for the exhaust manifold bolts on a 2002-2004 Infiniti I35?

The torque specification for the exhaust manifold bolts on a 2002-2004 Infiniti I35 is typically 16-20 ft-lbs (22-27 Nm). Always refer to the vehicle's service manual for precise values, as variations may exist depending on the engine model or aftermarket components.

Q2

Can I reuse exhaust bolts, or should they be replaced?

Exhaust bolts are often exposed to high heat and corrosion, which can weaken them over time. It is generally recommended to replace them with new bolts to ensure proper torque and prevent leaks. Reusing old bolts may lead to improper sealing or bolt failure.

Q3

What happens if I over-torque the exhaust bolts?

Over-torquing exhaust bolts can cause them to stretch or break, leading to exhaust leaks or damage to the manifold or cylinder head. Always use a calibrated torque wrench and follow the manufacturer's specifications to avoid over-tightening.

Q4

How often should I check the torque on my exhaust bolts?

It is a good practice to check the torque on exhaust bolts after the first 500-1,000 miles following installation, as heat cycles can cause bolts to loosen. After that, inspect them during routine maintenance or if you notice symptoms like exhaust leaks or unusual noises.

Environmental Considerations

Temperature, humidity, and seasonal effects on torque specifications

Temperature Effects

Includes: High Heat, Cold Weather, Thermal Cycling

Temperature can significantly impact torque values and fastener behavior

Cold Weather

Effects:
  • Increased material brittleness
  • Higher torque required due to thread contraction
  • Reduced thread lubricant effectiveness
Recommendations:
  • Allow components to warm to room temperature when possible
  • Consider using winter-grade thread lubricants
  • Check torque values more frequently during winter months

Hot Weather

Effects:
  • Thermal expansion of components
  • Decreased friction in threads
  • Accelerated lubricant breakdown
Recommendations:
  • Check torque when components are at normal operating temperature
  • Use temperature-resistant thread lockers
  • Consider re-torquing after heat cycles

Humidity and Corrosion

Covers: Rust Prevention, Salt Exposure, Moisture Control

Moisture and corrosion can affect fastener integrity and torque values

High Humidity

Effects:
  • Accelerated corrosion formation
  • Reduced friction coefficient
  • Potential thread seizing
Prevention:
  • Use corrosion-resistant fasteners
  • Apply appropriate anti-seize compounds
  • Maintain proper protective coatings

Salt Exposure

Effects:
  • Rapid corrosion development
  • Thread damage
  • Seized fasteners
Prevention:
  • Regular underbody washing
  • Use of sacrificial anodes where appropriate
  • Application of protective coatings

Seasonal Maintenance

Spring, Summer, Fall, and Winter maintenance schedules

Spring

  • Inspect for winter damage
  • Clean and protect exposed fasteners
  • Check torque on critical components

Summer

  • Monitor heat-affected components
  • Check expansion-related loosening
  • Inspect cooling system mounts

Fall

  • Prepare for winter conditions
  • Apply corrosion protection
  • Verify all fasteners are properly torqued

Winter

  • More frequent inspection of critical fasteners
  • Check for salt damage
  • Monitor suspension component torque

Related Resources

Tools, service procedures, and technical bulletins

Recommended Tools

Torque Wrench

A precision tool used to apply a specific torque to a fastener, such as exhaust bolts.

  • Adjustable torque settings
  • Durable construction for automotive use
Learn more

Socket Set

A set of sockets in various sizes to fit exhaust bolts and nuts.

  • Includes both metric and standard sizes
  • Compatible with torque wrench
Learn more

Breaker Bar

A long-handled tool used to loosen tight bolts before applying torque.

  • High leverage for tough bolts
  • Durable steel construction
Learn more
Service Procedures

Exhaust Manifold Bolt Torque Specification

Procedure to properly torque the exhaust manifold bolts on a 2002-2004 Infiniti I35.

  • Ensure the engine is cool before starting.
  • Remove any components obstructing access to the exhaust manifold bolts.
  • Use a breaker bar to loosen the bolts if necessary.
  • Tighten the bolts in a crisscross pattern to the specified torque of 18-22 ft-lbs (24-30 Nm).
  • Double-check the torque with a calibrated torque wrench.
View full procedure

Exhaust Pipe Flange Bolt Torque Specification

Procedure to properly torque the exhaust pipe flange bolts on a 2002-2004 Infiniti I35.

  • Ensure the exhaust system is cool before starting.
  • Inspect the flange gasket for damage and replace if necessary.
  • Tighten the flange bolts evenly to the specified torque of 25-30 ft-lbs (34-41 Nm).
  • Recheck the torque after the engine has been run and the system has cooled.
View full procedure
Technical Service Bulletins

Exhaust Manifold Bolt Loosening Issue

2003-05-15

Some 2002-2004 Infiniti I35 models may experience loosening of exhaust manifold bolts due to thermal cycling.

2002-2004 Infiniti I35

Resolution: Apply thread locker to the bolts and retorque to the specified 18-22 ft-lbs (24-30 Nm).

Exhaust Leak at Flange Connection

2004-08-20

A small number of 2002-2004 Infiniti I35 models may develop exhaust leaks at the flange connection due to improper torque.

2002-2004 Infiniti I35

Resolution: Inspect the flange gasket and bolts. Replace the gasket if damaged and retorque the bolts to 25-30 ft-lbs (34-41 Nm).

About the Author

Expert automotive knowledge and experience

Alan Montanye - Automotive Technical Specialist
ASE

Alan Montanye

Automotive Technical Specialist

ASE Master Certified Technician with over a decade of hands-on experience in automotive repair and diagnostics.

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