Audi Audi S5 2007-2016 Exhaust System Bolt Torque Specifications
Detailed torque specifications for all exhaust system bolts on the 2007-2016 Audi S5, including manifold, downpipe, and cat-back connections.
Important Information
Safety guidelines and reference information for proper torque application
Safety First
- Always verify torque specifications with your vehicle's factory service manual
- Use properly calibrated torque wrenches
- Replace all torque-to-yield (TTY) bolts - they are single-use only
- When in doubt, consult a professional mechanic
Quick Reference Guide
Quick Reference Guide
Common Torque Patterns
Star Pattern
Used for wheels and other circular bolt patterns
Cross Pattern
Used for gaskets and cover plates
Sequential Pattern
Used for head bolts and other critical components
Common Mistakes to Avoid
Common Mistakes to Avoid
Over-tightening
Exceeding the specified torque value can stretch or break fasteners, damage threads, or crack components.
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.
Follow the manufacturer's specified torque sequence pattern.
Dirty Threads
Dirt, rust, or old thread locker can affect torque readings and proper fastener tension.
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.
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.
Check if specs are for dry or lubricated threads. Use specified lubricant when required.
Recommended Tools
Recommended Tools
Torque Wrench (1/4" Drive)
Torque Wrench (3/8" Drive)
Torque Wrench (1/2" Drive)
Angle Gauge
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
Components associated with the exhaust manifold, connecting directly to the engine's cylinder head.
1 Exhaust Manifold to Cylinder Head Bolts
M8 x 1.25
Exhaust Manifold to Cylinder Head Bolts
M8 x 1.25Important Notes
2 Exhaust Manifold to Downpipe Bolts/Nuts
M10 x 1.5
Exhaust Manifold to Downpipe Bolts/Nuts
M10 x 1.5Important Notes
Downpipe
Components associated with the downpipes and catalytic converters, connecting to the exhaust manifold and mid-pipe.
1 Downpipe to Mid-Pipe/Catalytic Converter Flange Bolts/Nuts
M10 x 1.5
Downpipe to Mid-Pipe/Catalytic Converter Flange Bolts/Nuts
M10 x 1.5Important Notes
Midpipe And Muffler
Components associated with the mid-pipe and muffler section, connecting to the downpipe and exhaust tip.
1 Mid-Pipe to Rear Muffler Section Bolts/Clamps
M8 x 1.25
Mid-Pipe to Rear Muffler Section Bolts/Clamps
M8 x 1.25Torque Value
Important Notes
Exhaust Hangers
Components that support the exhaust system to the chassis.
1 Exhaust Hanger Bracket Bolts to Chassis
M8 x 1.25
Exhaust Hanger Bracket Bolts to Chassis
M8 x 1.25Torque Value
Important Notes
Exhaust Clamps
Components that provide a secure seal when slip-fitting pipes together.
1 Exhaust System Clamp Bolts
M8 x 1.25
Exhaust System Clamp Bolts
M8 x 1.25Torque Value
Important Notes
Sensors
Components that monitor the exhaust system
1 Oxygen Sensor (O2 Sensor)
N/A
Oxygen Sensor (O2 Sensor)
N/ATorque Value
Important Notes
Heat Shields
Components that protect other parts from exhaust heat.
1 Heat Shield Bolts
M6 x 1.0
Heat Shield Bolts
M6 x 1.0Torque Value
Important Notes
Troubleshooting Guide
Common issues, diagnostic steps, and prevention guidelines
Common Issues
Bolt stretching, stripped threads, uneven torque patterns
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
Diagnostic Steps
Visual inspection, torque verification, thread assessment
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
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
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
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 happens if I overtighten exhaust bolts?
What happens if I overtighten exhaust bolts?
Overtightening exhaust bolts can stretch or break the bolt, damage the threads in the flange, and crush the gasket, leading to leaks and potential exhaust system failure. For example, if you force a bolt beyond its specified torque, you may strip the threads in the catalytic converter housing, requiring costly repairs.
Q2 What happens if I undertighten exhaust bolts?
What happens if I undertighten exhaust bolts?
Undertightening exhaust bolts can result in exhaust leaks, which are not only noisy but also potentially dangerous, as they may allow harmful gases to enter the cabin. You might experience a noticeable exhaust noise increase and decreased engine performance due to back pressure issues.
Q3 Should I use new bolts every time I reassemble the exhaust system?
Should I use new bolts every time I reassemble the exhaust system?
It is highly recommended to use new bolts and gaskets whenever you disassemble the exhaust system. Old bolts can be stretched or corroded, making them less reliable and preventing a proper seal. Reusing old gaskets often results in leaks. New hardware ensures proper torque can be achieved and maintains a leak-free exhaust system.
Q4 Do I need to use any special tools for tightening exhaust bolts?
Do I need to use any special tools for tightening exhaust bolts?
Yes, a torque wrench is essential. Using a regular wrench without a torque measurement risks overtightening or undertightening the bolts. You may also need extensions, swivel adapters and possibly a penetrating lubricant to help remove stubborn bolts. Always use the correct socket size for the bolts to avoid slippage and damage.
Q5 Are the torque specifications different for different parts of the exhaust system?
Are the torque specifications different for different parts of the exhaust system?
Yes, generally, torque specifications differ based on bolt size and the components being joined. For example, the bolts connecting the downpipes to the exhaust manifold typically have a different torque spec than the bolts connecting the exhaust mid-pipes or muffler. Always refer to the specific service manual for the correct torque for each connection.
Environmental Considerations
Temperature, humidity, and seasonal effects on torque specifications
Temperature Effects
Includes: High Heat, Cold Weather, Thermal Cycling
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
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
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 (1/2" Drive)
A high-quality torque wrench is crucial for accurately tightening exhaust bolts to the manufacturer's specifications. A 1/2" drive is recommended for the torque range required for exhaust components.
- Click-type mechanism for accurate torque setting
- Clear and easy-to-read torque scale
- Durable construction for long-term use
Torque Wrench (3/8" Drive)
A 3/8" drive torque wrench might be needed for smaller bolts or areas where the 1/2" drive might not be accessible.
- Click-type mechanism for accurate torque setting
- Clear and easy-to-read torque scale
- More compact design
Socket Set (Metric)
A comprehensive metric socket set, including various sizes of sockets (typically 13mm, 16mm, and 17mm), is required to fit the different bolts found on the exhaust system.
- Variety of sizes to fit different bolts
- Durable chrome vanadium construction
- 6-point design for secure grip
Extension Bars (Various Lengths)
Extension bars are essential for reaching recessed or hard-to-access exhaust bolts. Different lengths offer flexibility.
- Allows access to recessed areas
- Durable construction
- Available in different lengths
Universal Joint
A universal joint allows the socket to turn at an angle, which is helpful for tightening bolts at difficult angles
- Allows flexible socket positioning
- Durable construction
Penetrating Oil
Used to help loosen corroded or stuck bolts. Application should be allowed to sit before attempting removal.
- Loosens rust and corrosion
- Reduces the risk of bolt damage
Service Procedures
Exhaust System Bolt Torque Procedure
This procedure outlines the general steps for torquing exhaust system bolts on a 2007-2016 Audi S5. Always refer to a vehicle-specific repair manual for exact specifications.
- 1. Identify all exhaust system connections and the corresponding bolts or fasteners.
- 2. Refer to the Audi S5 repair manual to determine the specific torque specifications for each exhaust connection (typically ranging from 25-40 Nm depending on the location and size of the bolt).
- 3. If any bolts are rusted or corroded, apply penetrating oil and allow sufficient time for it to soak.
- 4. Ensure the mating surfaces of the exhaust flanges are clean and free of any debris or gasket residue.
- 5. Install new gaskets or seals if recommended by service manual.
- 6. Install bolts to proper torque sequence (generally working in a circular or criss-cross pattern).
- 7. Tighten the bolts evenly, gradually increasing the torque, using the torque wrench set to the appropriate specification.
- 8. Verify torque once the specified torque is reached.
- 9. After a short test drive, check the torque of the bolts again to confirm that they are still within the specified range.
Catalytic Converter Bolt Torque Procedure
This procedure outlines the torque procedure for catalytic converter bolts, following the general exhaust system torque procedure.
- 1. Locate the catalytic converter to exhaust flange bolts.
- 2. Use the socket and torque wrench to tighten the bolts to the manufacturers specifications, which is generally within 25-40 Nm
- 3. Follow the procedure listed in the 'Exhaust System Bolt Torque Procedure' to check the torque after initial assembly and after a short test drive.
Technical Service Bulletins
Exhaust System Fastener Corrosion
2012-05-15This bulletin addresses issues with corrosion on exhaust system fasteners, especially in areas prone to road salt exposure, which may result in difficult removal or torque application.
Resolution: Use penetrating oil on rusted bolts prior to removal. Replace any heavily corroded fasteners. Use anti-seize compound on threads during re-installation. Regularly inspect exhaust components for rust and corrosion.
Exhaust Leaks Due to Improper Torque
2014-11-20This bulletin highlights that exhaust leaks can result from improperly torqued exhaust bolts, leading to performance issues and noise. Ensure the proper torque is applied to the exhaust system bolts.
Resolution: Always use a calibrated torque wrench. Refer to the vehicle's service manual for correct torque specifications. Inspect exhaust gaskets and replace them when reinstalling exhaust components.
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Technical Information
- All specifications, including torque values, fluid capacities, and maintenance procedures, should be verified against your vehicle's factory service manual.
- Vehicle specifications and procedures may vary by model year, trim level, and region.
- Always follow the manufacturer's recommended procedures and safety precautions.
- Working on vehicles can be dangerous. Always take proper safety precautions and use appropriate safety equipment.
- If you're unsure about any procedure, consult a qualified professional mechanic.