Audi Audi A7 2018-present 2.9L Engine Bolt Torque Specifications & Fastener Values
Audi Audi A7 2018-present

Audi Audi A7 2018-present 2.9L Engine Bolt Torque Specifications

Comprehensive guide to bolt torque specifications for the 2.9-liter engine found in the 2018 and newer Audi A7. Includes torque values for various engine components.

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

Engine Mounting And Support

Components related to securing the engine and transmission to the vehicle chassis. Proper torque is critical for vibration damping and preventing movement.

1

Engine Mount-to-Chassis Bolts

M12 x 1.5
Important Notes
Critical fasteners for securely mounting the engine to the vehicle's frame. Estimated value based on similar Audi models.
2

Engine Mount-to-Engine Bracket Bolts

M10 x 1.5
Important Notes
Secures the engine mount to the engine. Estimated value based on similar Audi models.
3

Transmission Mount Bolts

M12 x 1.5
Important Notes
Bolts that hold the transmission to the chassis, estimated value based on similar Audi models.

Cylinder Head And Components

Fasteners related to the cylinder head, camshafts, and valve cover. Proper torque is crucial for sealing the combustion chamber and preventing leaks.

1

Cylinder Head Bolts

M12 x 1.75
Important Notes
Multi-stage torque procedure. Estimated values based on industry standards for similar metric head bolts, proper sequence MUST be followed.
2

Camshaft Bearing Cap Bolts

M8 x 1.25
Important Notes
Secures the camshaft to the head. Estimated based on similar Audi models, use proper sequence.
3

Valve Cover Bolts

M6 x 1.0
Torque Value
7 ft-lbs (9 N·m)
Important Notes
Seals the valve cover to the cylinder head. Estimated based on industry standards, do not over tighten.

Intake And Exhaust Systems

Fasteners related to the intake and exhaust manifolds, turbocharger, and downpipe. Proper torque is essential for creating airtight and leak-free seals.

1

Intake Manifold Bolts

M8 x 1.25
Torque Value
11 ft-lbs (15 N·m)
Important Notes
Secures the intake manifold to the cylinder head. Estimated based on similar Audi models.
2

Exhaust Manifold Bolts

M8 x 1.25
Torque Value
22 ft-lbs (30 N·m)
Important Notes
Secures the exhaust manifold to the cylinder head. Estimated based on industry standards.
3

Turbocharger Mounting Bolts

M10 x 1.5
Torque Value
25 ft-lbs (34 N·m)
Important Notes
Mounts the turbocharger to the exhaust manifold and/or engine block. Estimated based on similar Audi models.
4

Downpipe Flange Bolts

M10 x 1.5
Torque Value
30 ft-lbs (40 N·m)
Important Notes
Connect the exhaust downpipe to the turbo or exhaust manifold. Estimated based on industry standards.

Engine Internals

Fasteners related to the internal components of the engine including connecting rods, main bearings, oil pan, and flywheel. Proper torque is vital for safe engine operation.

1

Connecting Rod Bolts

M9 x 1.0
Important Notes
Fastens the connecting rod to the crankshaft. Estimated value based on industry standards, proper sequence MUST be followed.
2

Main Bearing Cap Bolts

M12 x 1.75
Important Notes
Secures the crankshaft to the engine block. Estimated based on similar Audi models, proper sequence MUST be followed.
3

Oil Pan Bolts

M6 x 1.0
Torque Value
7 ft-lbs (10 N·m)
Important Notes
Secures the oil pan to the engine block. Estimated based on industry standards, do not over tighten.
4

Oil Pump Bolts

M6 x 1.0
Important Notes
Mounts the oil pump to the engine block. Estimated based on industry standards.
5

Flywheel/Flexplate Bolts

M10 x 1.5
Important Notes
Attaches the flywheel or flexplate to the crankshaft. Estimated value based on similar Audi models, proper sequence MUST be followed.

Cooling And Lubrication Systems

Components related to the engine's cooling and oil systems including water pump, thermostat housing, and oil cooler. Proper torque is essential for preventing leaks and ensuring proper fluid flow.

1

Water Pump Bolts

M6 x 1.0
Torque Value
7 ft-lbs (10 N·m)
Important Notes
Secures the water pump to the engine block. Estimated value based on industry standards.
2

Thermostat Housing Bolts

M6 x 1.0
Torque Value
7 ft-lbs (10 N·m)
Important Notes
Secures the thermostat housing. Estimated based on industry standards.
3

Oil Cooler Bolts

M8 x 1.25
Torque Value
22 ft-lbs (30 N·m)
Important Notes
Bolts for the oil cooler assembly. Estimated based on industry standards.

Miscellaneous

Fasteners for various engine components not covered in other sections. Includes the accessory drive belt tensioner and crankshaft pulley. Proper torque is crucial for overall engine performance and safety.

1

Accessory Drive Belt Tensioner Bolt

M10 x 1.5
Torque Value
22 ft-lbs (30 N·m)
Important Notes
Secures the belt tensioner to the engine. Estimated based on similar Audi models.
2

Crankshaft Pulley Bolt

M18 x 1.5
Important Notes
Attaches the crankshaft pulley to the crankshaft. Estimated value based on similar Audi models.

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

Why are correct torque specifications important for the 2.9L engine?

Using the correct torque ensures proper clamping force, preventing leaks, loosening of components, and potential damage to the engine block, cylinder head, and related parts. For example, overtightening head bolts can cause thread damage or distortion, leading to compression leaks or head gasket failure. Undertightening can result in oil leaks or loosening over time. Precise torque is critical for the long-term integrity of this high-performance engine.

Q2

What happens if I overtighten a bolt on the 2.9L engine?

Overtightening can cause a variety of problems, including stretching or breaking the bolt, stripping threads in the engine block or component, and warping or damaging the clamped parts. For instance, overtightening the oil pan bolts can crush the gasket, leading to leaks and possibly requiring replacement of the pan. It's crucial to use a properly calibrated torque wrench to prevent this.

Q3

Can I reuse torque-to-yield (TTY) bolts on the 2.9L engine?

No, torque-to-yield (TTY) bolts are designed to stretch when tightened and should NEVER be reused. These bolts, often used on the cylinder head and crankshaft, are engineered to provide very precise clamping force, and their structural integrity is compromised upon initial use. Reusing them risks improper clamping, loosening, or even catastrophic failure. Always replace TTY bolts with new ones during reassembly.

Q4

How often should I check torque settings on my 2.9L engine components?

Generally, torque checks are recommended after any major service or when components are removed and reinstalled. Specifically, following a cylinder head replacement or intake manifold removal, re-torqueing may be advised after a short initial run-in period (around 500-1000 miles) to account for material settling, depending on the specific procedure. Regular visual inspections for leaks or loose components are also wise.

Q5

What type of lubricant should I use on threaded fasteners for the 2.9L engine?

The type of lubricant or threadlocker varies by application. Generally, engine component bolts and studs are assembled clean and dry unless otherwise specified by the manufacturer. For those requiring lubrication, such as cylinder head bolts with an oil-based lubricant, use the specified lubricant. Certain areas require a threadlocking agent such as Loctite, which prevents loosening and is typically used in areas prone to vibration. Always refer to the repair manual for guidance on specific fastener lubrication.

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 (1/4" Drive)

A 1/4" drive torque wrench is essential for applying precise torque to smaller bolts.

  • Accurate torque settings
  • Click mechanism for feedback
Learn more

Torque Wrench (3/8" Drive)

A 3/8" drive torque wrench is suitable for medium-sized bolts and fasteners.

  • Wider torque range
  • Durable construction
Learn more

Torque Wrench (1/2" Drive)

A 1/2" drive torque wrench is required for larger fasteners and higher torque applications.

  • High torque capacity
  • Robust build quality
Learn more

Socket Set (Metric)

A comprehensive metric socket set is needed to fit various bolt heads on the 2.9L engine.

  • Variety of sizes
  • Durable material
Learn more

Extension Bars

Extension bars are useful for accessing bolts in tight or hard-to-reach areas.

  • Various lengths
  • Provides reach
Learn more

Universal Joint

A universal joint allows socket rotation at an angle, useful for awkwardly placed bolts.

  • Flexible articulation
  • Improves accessibility
Learn more

Torx Socket Set

A set of torx sockets, needed to apply torque to star-shaped bolts.

  • Variety of sizes
  • Durable material
Learn more
Service Procedures

Cylinder Head Bolt Tightening Procedure (2.9L Engine)

This procedure outlines the correct sequence and torque specifications for tightening the cylinder head bolts on a 2.9L engine.

  • Clean all mating surfaces of the cylinder head and block.
  • Install new cylinder head bolts.
  • Tighten all cylinder head bolts to 40 Nm (29.5 lb-ft) following the specified sequence.
  • Tighten all cylinder head bolts an additional 90 degrees following the specified sequence.
  • Tighten all cylinder head bolts another additional 90 degrees following the specified sequence.
  • Verify the torque and angles with a torque angle meter and wrench.
View full procedure

Intake Manifold Bolt Tightening Procedure (2.9L Engine)

This procedure covers the correct method for torquing the intake manifold bolts.

  • Clean the intake manifold and cylinder head mating surfaces.
  • Install the intake manifold and start all bolts by hand.
  • Tighten the bolts to 10 Nm (7.4 lb-ft) following the specified sequence.
  • Verify torque with a calibrated wrench.
View full procedure

Valve Cover Bolt Tightening Procedure (2.9L Engine)

This procedure details how to properly tighten the valve cover bolts.

  • Clean the valve cover and cylinder head mating surfaces.
  • Install the valve cover and new gasket, start all bolts by hand.
  • Tighten the bolts to 10 Nm (7.4 lb-ft) following the specified sequence.
  • Verify torque with a calibrated wrench.
View full procedure

Camshaft Bearing Cap Bolt Tightening Procedure (2.9L Engine)

This procedure outlines the correct method for tightening the camshaft bearing cap bolts.

  • Ensure proper camshaft alignment.
  • Install the bearing caps and start all bolts by hand.
  • Tighten the bolts to 8 Nm (6 lb-ft) following the specified sequence.
  • Tighten the bolts an additional 90 degrees following the specified sequence.
  • Verify torque and angle with a torque angle meter and wrench.
View full procedure
Technical Service Bulletins

Engine Oil Leak at Cylinder Head

2020-07-15

Some 2.9L engines may exhibit an oil leak due to improper head bolt torque during manufacturing. This can be identified by oil seeping from the cylinder head.

2018-2020 A7 with 2.9L Engine

Resolution: Re-torque cylinder head bolts to the correct specifications and replace head gasket if necessary.

Intake Manifold Gasket Leak

2021-11-01

Some vehicles are experiencing intake manifold gasket leaks, leading to vacuum leaks and poor engine performance. This may be due to insufficient torque on manifold bolts

2019-2021 A7 with 2.9L Engine

Resolution: Inspect the intake manifold gasket for damage, replace if needed, and tighten bolts to the specified torque.

About the Author

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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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  • All specifications, including torque values, fluid capacities, and maintenance procedures, should be verified against your vehicle's factory service manual.
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