Hyundai Ioniq 2017-present Exhaust System Bolt Torque Specifications & Gasket Sealing
Hyundai Ioniq 2017-present

Hyundai Ioniq 2017-present Exhaust System Bolt Torque Specifications

Detailed torque specifications for the exhaust bolts of the 2017-Present Hyundai IONIQ, including proper tightening procedures and recommended torque values.

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. Proper torque ensures a tight seal to prevent exhaust gas leaks, which could affect engine performance and emissions.

1

Exhaust Manifold/Headers to Cylinder Head Bolts

M8 x 1.25
Torque Value
18 ft-lbs (24.5 N·m)
Important Notes
Ensure bolts are tightened in a crisscross pattern to evenly distribute pressure.
2

Exhaust Pipe to Exhaust Manifold/Headers Bolts

M8 x 1.25
Torque Value
18 ft-lbs (24.5 N·m)
Important Notes
Ensure a secure connection to prevent leaks at this critical junction.

Catalytic Converter

This subsystem includes components that connect the catalytic converter to the exhaust pipe. Proper torque ensures a leak-free connection, which is essential for maintaining proper exhaust flow and emissions control.

1

Catalytic Converter to Exhaust Pipe Bolts

M8 x 1.25
Torque Value
18 ft-lbs (24.5 N·m)
Important Notes
Ensure a secure connection to prevent leaks.

Muffler

This subsystem includes components that connect the muffler to the exhaust pipe. Correct torque ensures a secure fit and prevents exhaust leaks, which could lead to noise and performance issues.

1

Muffler to Exhaust Pipe Bolts

M8 x 1.25
Torque Value
18 ft-lbs (24.5 N·m)
Important Notes
Ensure a secure connection to prevent leaks.

Heat Shield

This subsystem includes components that attach heat shields to the exhaust system to protect surrounding components from excessive heat. Proper torque ensures the heat shield remains securely in place without over-tightening, which could damage the shield or exhaust components.

1

Exhaust Heat Shield Bolts

M6 x 1.0
Torque Value
7.2 ft-lbs (9.8 N·m)
Important Notes
Estimated value based on typical heat shield bolt sizes. Avoid over-tightening to prevent damage.

Exhaust Hangers

This subsystem includes components that support the weight of the exhaust system and prevent excessive movement. Proper torque ensures the hangers remain securely attached, reducing stress on the exhaust system and preventing premature wear or failure.

1

Exhaust Hanger Bolts

M8 x 1.25
Torque Value
18 ft-lbs (24.5 N·m)
Important Notes
Ensure a secure connection to prevent excessive movement.

Oxygen Sensor

This subsystem includes components that secure the oxygen sensor to the exhaust system. Proper torque ensures a secure fit and prevents leaks, which could lead to inaccurate sensor readings and affect engine performance.

1

Oxygen Sensor (O2 Sensor) Mounting Bolts

M8 x 1.25
Torque Value
18 ft-lbs (24.5 N·m)
Important Notes
Ensure a secure connection to prevent leaks and ensure accurate sensor readings.

Exhaust Flanges

This subsystem includes components that connect sections of the exhaust system using flange bolts. Proper torque ensures a tight seal and prevents leaks, which could affect exhaust flow and emissions.

1

Exhaust Flange Bolts

M8 x 1.25
Torque Value
18 ft-lbs (24.5 N·m)
Important Notes
Tighten bolts in a crisscross pattern to evenly distribute pressure.

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 2017-Present Hyundai IONIQ?

The recommended torque specification for the exhaust manifold bolts on a 2017-Present Hyundai IONIQ is typically between 20-25 Nm (15-18 ft-lbs). However, always refer to the vehicle's service manual for the exact specifications, as they may vary depending on the engine type and model year.

Q2

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

It is recommended to check the torque on exhaust system bolts during routine maintenance, such as oil changes or tire rotations, or if you notice any unusual noises or vibrations from the exhaust system. Loose bolts can lead to exhaust leaks, which can affect performance and emissions.

Q3

Can over-tightening exhaust bolts cause damage?

Yes, over-tightening exhaust bolts can strip the threads or damage the exhaust manifold, leading to costly repairs. Always use a torque wrench and follow the manufacturer's specifications to avoid over-tightening.

Q4

What should I do if an exhaust bolt is seized or broken?

If an exhaust bolt is seized or broken, it is best to use penetrating oil to loosen it or seek professional assistance. Attempting to force it can cause further damage to the exhaust system or surrounding components.

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 a bolt or nut.

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

Socket Set

A set of sockets and accessories used to tighten or loosen bolts and nuts.

  • Includes various socket sizes
  • Compatible with torque wrench
Learn more

Thread Locker

A chemical compound used to secure bolts and prevent them from loosening due to vibration.

  • High-temperature resistance
  • Prevents corrosion
Learn more
Service Procedures

Exhaust Manifold Bolt Torque Specification

Procedure to apply the correct torque to the exhaust manifold bolts on a 2017-Present Hyundai IONIQ.

  • Ensure the engine is cool before starting.
  • Remove any components obstructing access to the exhaust manifold bolts.
  • Clean the bolt threads and apply thread locker if recommended.
  • Using a torque wrench, tighten the exhaust manifold bolts to the specified torque in a crisscross pattern.
  • Reinstall any removed components and double-check the torque settings.
View full procedure

Exhaust Pipe Flange Bolt Torque Specification

Procedure to apply the correct torque to the exhaust pipe flange bolts on a 2017-Present Hyundai IONIQ.

  • Lift the vehicle and secure it on jack stands.
  • Locate the exhaust pipe flange connection.
  • Clean the bolt threads and apply thread locker if recommended.
  • Using a torque wrench, tighten the flange bolts to the specified torque in a star pattern.
  • Lower the vehicle and start the engine to check for exhaust leaks.
View full procedure
Technical Service Bulletins

Exhaust System Bolt Loosening Issue

2021-05-15

Some 2017-Present Hyundai IONIQ vehicles may experience loosening of exhaust system bolts due to vibration.

2017-2023 Hyundai IONIQ

Resolution: Inspect and retorque all exhaust system bolts to the manufacturer's specifications. Apply thread locker if necessary.

Exhaust Manifold Bolt Corrosion

2022-08-10

Reports of exhaust manifold bolt corrosion leading to difficulty in removal or breakage.

2017-2023 Hyundai IONIQ

Resolution: Replace corroded bolts with new, high-quality bolts and apply anti-seize compound during installation.

About the Author

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Alan Montanye - Automotive Technical Specialist
ASE

Alan Montanye

Automotive Technical Specialist

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