Volvo Volvo S90 2016-present Exhaust System Bolt Torque Specifications & Gasket Sealing
Volvo Volvo S90 2016-present

Volvo Volvo S90 2016-present Exhaust System Bolt Torque Specifications

Detailed technical specifications for the exhaust bolt torque settings of the 2016-Present Volvo S90, ensuring proper installation and performance.

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 the exhaust manifold or headers, which collect exhaust gases from the engine cylinders and direct them into the exhaust pipe. Proper torque on these bolts ensures a gas-tight seal, preventing leaks that could affect engine performance and emissions.

1

Exhaust Manifold/Headers Bolts

M8 x 1.25
Torque Value
22 ft-lbs (30 N·m)
Important Notes
Ensure bolts are torqued in a criss-cross pattern starting from the center outward.
2

Exhaust Manifold/Headers to Cylinder Head Bolts

M8 x 1.25
Torque Value
22 ft-lbs (30 N·m)
Important Notes
Ensure bolts are torqued in a criss-cross pattern starting from the center outward.

Exhaust Pipe

This subsystem includes the exhaust pipe, which carries exhaust gases from the manifold or headers to the catalytic converter and muffler. Proper torque on these bolts ensures a secure connection and prevents exhaust leaks.

1

Exhaust Pipe to Exhaust Manifold/Headers Bolts

M8 x 1.25
Torque Value
22 ft-lbs (30 N·m)
Important Notes
Ensure the exhaust pipe is properly aligned before torquing.
2

Catalytic Converter to Exhaust Pipe Bolts

M8 x 1.25
Torque Value
22 ft-lbs (30 N·m)
Important Notes
Ensure the catalytic converter is properly aligned before torquing.
3

Muffler to Exhaust Pipe Bolts

M8 x 1.25
Torque Value
22 ft-lbs (30 N·m)
Important Notes
Ensure the muffler is properly aligned before torquing.
4

Exhaust Flange Bolts

M8 x 1.25
Torque Value
18 ft-lbs (25 N·m)
Important Notes
Ensure the flanges are properly aligned before torquing.

Exhaust Support

This subsystem includes components that support the exhaust system, such as hangers and heat shields. Proper torque on these bolts ensures the exhaust system remains securely attached and protected from excessive heat.

1

Exhaust Hanger Bolts

M6 x 1.0
Torque Value
15 ft-lbs (20 N·m)
Important Notes
Ensure the hanger is properly aligned before torquing.
2

Exhaust Heat Shield Bolts

M6 x 1.0
Torque Value
7 ft-lbs (10 N·m)
Important Notes
Be cautious not to overtighten, as heat shields are typically made of thin metal.

Oxygen Sensor

This subsystem includes the oxygen sensor, which monitors the oxygen content in the exhaust gases. Proper torque on these bolts ensures a secure fit and accurate sensor readings.

1

Oxygen Sensor Bolts

M8 x 1.25
Torque Value
25 ft-lbs (34 N·m)
Important Notes
Ensure the oxygen sensor is properly seated before torquing.

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 recommended torque specification for the exhaust manifold bolts on a 2016-Present Volvo S90?

The recommended torque specification for the exhaust manifold bolts on a 2016-Present Volvo S90 is typically between 20-25 Nm (Newton-meters). However, always refer to the manufacturer’s service manual for your specific model and engine type, as variations may exist.

Q2

Is it necessary to re-torque exhaust bolts after driving for a certain period?

Yes, it is advisable to re-torque exhaust bolts after the first 50-100 miles of driving. Heat cycles can cause the bolts to loosen slightly, and re-torquing ensures they remain secure and prevent exhaust leaks.

Q3

Can I use thread locker on exhaust bolts?

Yes, a high-temperature thread locker can be used on exhaust bolts to prevent them from loosening due to vibrations and heat. However, ensure the thread locker is rated for high temperatures (typically 700°F or higher) to maintain its effectiveness.

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
  • Ergonomic handle for ease of use
Learn more

Socket Set

A set of sockets compatible with exhaust bolts for secure attachment.

  • Various sizes included
  • Durable material for long-lasting use
Learn more

Thread Locker

A chemical compound used to prevent loosening of bolts due to vibration.

  • High-temperature resistance
  • Easy application
Learn more
Service Procedures

Exhaust Bolt Torque Specification Application

Detailed steps to correctly apply the torque specifications to the exhaust bolts of a 2016-Present Volvo S90.

  • Ensure the vehicle is on a flat surface and the exhaust system is cool.
  • Locate the exhaust bolts that need tightening or replacement.
  • Clean the bolt threads and apply a small amount of thread locker if necessary.
  • Attach the correct socket to the torque wrench and set the torque to the specified value (e.g., 25 Nm for exhaust manifold bolts).
  • Tighten the bolts in a crisscross pattern to ensure even pressure.
  • Double-check the torque settings and verify all bolts are securely fastened.
View full procedure
Technical Service Bulletins

Exhaust System Bolt Loosening Issue

2018-05-15

Reports of exhaust system bolts loosening over time due to vibration and heat cycles.

2016-2018 Volvo S90

Resolution: Recommend using a thread locker and re-torquing bolts to the specified value during routine maintenance.

Updated Torque Specifications for Exhaust Bolts

2020-09-10

Revised torque specifications for exhaust system bolts to improve durability.

2016-Present Volvo S90

Resolution: Refer to the latest service manual for updated torque values and ensure compliance during repairs.

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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