Audi Audi Q5 2017-present HVAC System Bolt Torque Specifications
Audi Audi Q5 2017-present

Audi Audi Q5 2017-present HVAC System Bolt Torque Specifications

This page provides detailed torque specifications for bolts used in the HVAC system of the second-generation (2017-Present) Audi Q5. Includes torque values for various components within the HVAC system.

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

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Torque Calculator

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Compressor

Components and fasteners related to the A/C compressor, including mounting, clutch, and line connections.

1

Compressor Mounting Bolt (Engine Block/Bracket)

M8 x 1.25
Torque Value
18 ft-lbs (25 N·m)
Important Notes
Secures the compressor to the engine block or mounting bracket. Proper torque is crucial for preventing vibration, leaks, and damage to the compressor and engine.
2

Compressor Mounting Bolt (Engine Block/Bracket)

M10 x 1.5
Torque Value
30 ft-lbs (40 N·m)
Important Notes
Secures the compressor to the engine block or mounting bracket. Proper torque is crucial for preventing vibration, leaks, and damage to the compressor and engine.
3

Compressor Clutch Electrical Connector Bolt

M5 x 0.8
Torque Value
4.5 ft-lbs (6 N·m)
Important Notes
Secures the electrical connector to the compressor clutch. Prevents a loose connection which could cause electrical problems with the clutch or other issues. Estimated value.
4

A/C Line Fitting Bolt (Compressor)

M6 x 1.0
Torque Value
7 ft-lbs (10 N·m)
Important Notes
Secures A/C lines to the compressor. Use new o-rings or gaskets. Overtightening can damage the aluminum fittings and cause leaks; under-tightening can also lead to refrigerant leaks. Estimated value.
5

A/C Line Fitting Bolt (Compressor)

M8 x 1.25
Torque Value
14 ft-lbs (19 N·m)
Important Notes
Secures A/C lines to the compressor (larger fittings). Use new o-rings or gaskets. Overtightening can damage the aluminum fittings and cause leaks; under-tightening can also lead to refrigerant leaks. Estimated value.

Condenser

Components and fasteners related to the A/C condenser, including mounting and line connections.

1

Condenser Mounting Bolt

M6 x 1.0
Torque Value
7 ft-lbs (10 N·m)
Important Notes
Secures the condenser to the radiator support or chassis. Prevents movement or vibration, which could cause damage to the condenser or lines. Estimated value.
2

Condenser Mounting Bolt

M8 x 1.25
Torque Value
18 ft-lbs (25 N·m)
Important Notes
Secures the condenser to the radiator support or chassis. Prevents movement or vibration, which could cause damage to the condenser or lines.
3

A/C Line Fitting Bolt (Condenser)

M6 x 1.0
Torque Value
7 ft-lbs (10 N·m)
Important Notes
Secures A/C lines to the condenser. Use new o-rings or gaskets. Overtightening can damage the aluminum fittings and cause leaks; under-tightening can also lead to refrigerant leaks. Estimated value.
4

A/C Line Fitting Bolt (Condenser)

M8 x 1.25
Torque Value
14 ft-lbs (19 N·m)
Important Notes
Secures A/C lines to the condenser (larger fittings). Use new o-rings or gaskets. Overtightening can damage the aluminum fittings and cause leaks; under-tightening can also lead to refrigerant leaks. Estimated value.

Receiver Drier

Components and fasteners related to the receiver drier, including mounting and line connections.

1

Receiver Drier Mounting Bracket Bolt

M6 x 1.0
Torque Value
7 ft-lbs (10 N·m)
Important Notes
Secures the receiver drier and its mounting bracket. Prevents vibration and damage and helps ensure correct fitting of the refrigerant line. Estimated value.
2

A/C Line Fitting Bolt (Receiver Drier)

M6 x 1.0
Torque Value
7 ft-lbs (10 N·m)
Important Notes
Secures A/C lines to the receiver drier. Use new o-rings or gaskets. Overtightening can damage the aluminum fittings and cause leaks; under-tightening can also lead to refrigerant leaks. Estimated value.
3

A/C Line Fitting Bolt (Receiver Drier)

M8 x 1.25
Torque Value
14 ft-lbs (19 N·m)
Important Notes
Secures A/C lines to the receiver drier (larger fittings). Use new o-rings or gaskets. Overtightening can damage the aluminum fittings and cause leaks; under-tightening can also lead to refrigerant leaks. Estimated value.

Evaporator

Components and fasteners related to the A/C evaporator, including housing, expansion valve, and line connections.

1

Evaporator Housing Bolt (Plastic Housing)

M6 x 1.0
Torque Value
5 ft-lbs (7 N·m)
Important Notes
Secures the two halves of the evaporator housing together. These plastic components should be tightened carefully to avoid cracking. Often not fully tightened until all fasteners are started. Estimated value.
2

Evaporator Housing Bolt

M8 x 1.25
Torque Value
18 ft-lbs (25 N·m)
Important Notes
Secures the evaporator housing or bracket in place in the vehicle. Ensures stability and proper positioning for the HVAC system components.
3

Expansion Valve Mounting Bolt

M5 x 0.8
Torque Value
4.5 ft-lbs (6 N·m)
Important Notes
Secures the expansion valve to the evaporator. Ensures a proper seal at the valve connections. Estimated value.
4

A/C Line Fitting Bolt (Evaporator)

M6 x 1.0
Torque Value
7 ft-lbs (10 N·m)
Important Notes
Secures A/C lines to the evaporator. Use new o-rings or gaskets. Overtightening can damage the aluminum fittings and cause leaks; under-tightening can also lead to refrigerant leaks. Estimated value.
5

A/C Line Fitting Bolt (Evaporator)

M8 x 1.25
Torque Value
14 ft-lbs (19 N·m)
Important Notes
Secures A/C lines to the evaporator (larger fittings). Use new o-rings or gaskets. Overtightening can damage the aluminum fittings and cause leaks; under-tightening can also lead to refrigerant leaks. Estimated value.

Hvac Control

Components and fasteners related to the HVAC control module and actuators.

1

Control Module Mounting Bolt

M4 x 0.7
Torque Value
3 ft-lbs (4 N·m)
Important Notes
Secures the HVAC control module to the dashboard or bracket. Prevents vibration and ensures proper electrical connection, and prevents damage to the sensitive electronics module. Estimated value.
2

Blend Door Actuator Mounting Bolt (Plastic Actuator)

M4 x 0.7
Torque Value
2 ft-lbs (2.7 N·m)
Important Notes
Secures the blend door actuators. Over-tightening these bolts to the actuator housing can damage them as it is usually plastic. Estimated value.
3

Blend Door Actuator Mounting Bolt

M5 x 0.8
Torque Value
4.5 ft-lbs (6 N·m)
Important Notes
Secures the blend door actuators. Prevents movement and malfunction.

Heater Core

Components and fasteners related to the heater core.

1

Heater Core Housing Bolt

M6 x 1.0
Torque Value
7 ft-lbs (10 N·m)
Important Notes
Secures the heater core in position within its housing. Prevents movement and potential damage from the engine vibration. Estimated value.

Blower Motor

Components and fasteners related to the blower motor.

1

Blower Motor Mounting Bolt

M5 x 0.8
Torque Value
4.5 ft-lbs (6 N·m)
Important Notes
Secures the blower motor to the HVAC housing. Prevents vibration and ensures proper blower operation.

Ductwork

Fasteners used to secure the interior ductwork.

1

Ductwork Mounting Screw (Self-Tapping Plastic)

Self-Tapping (Estimated)
Torque Value
2.5 ft-lbs (3.5 N·m)
Important Notes
These fasteners attach plastic ductwork sections together or to the HVAC housing. Over-tightening can damage the plastic, while under-tightening could cause a lack of seal. Estimated value.

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 is using the correct torque specification important for HVAC components?

Using the correct torque specification ensures proper clamping force, preventing leaks of refrigerant and other fluids, as well as avoiding damage to threads or the component itself. Overtightening can lead to stripped threads, damaged seals, or cracked housings, resulting in costly repairs and system failure. Undertightening can cause leaks, vibrations, and component loosening.

Q2

What happens if I overtighten a bolt on my Audi Q5's HVAC system?

Overtightening bolts in the HVAC system, particularly on aluminum components like the condenser or compressor, can easily strip the threads in the housing or on the bolt itself. This can lead to the need for expensive repairs, such as replacing the entire component. Additionally, it can crush gaskets or O-rings, causing leaks that are difficult to seal. Imagine trying to reseal a refrigerant line that now has a warped flange due to overtightening - it becomes a much bigger job.

Q3

Can I reuse bolts from the HVAC system when reassembling?

While some bolts may appear reusable, it's generally recommended to replace bolts that secure critical components like the compressor or condenser. This is because they may have stretched or weakened after being torqued previously, and reusing them may result in them not holding torque. Using new bolts ensures proper clamping force, a tight seal, and reduces the risk of future issues. Specifically, replace torque-to-yield bolts as they cannot be used more than once.

Q4

Do the torque specs for different HVAC components vary?

Yes, absolutely. Different HVAC components within your Audi Q5, such as the condenser, compressor, evaporator, and lines, have different torque specifications. This is due to the different materials, connection types, and the required clamping force needed for each component. Always refer to the vehicle's service manual or relevant documentation for the correct torque specification for each specific bolt.

Q5

Where can I find the correct torque specifications for my 2017-Present Audi Q5 HVAC system?

The most reliable source is the official Audi service manual specific to your model year. This information can also be found in reputable online automotive repair databases, like Mitchell1 or Alldata. Be careful when using generalized charts, as they may not apply to all components on your Q5.

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)

Precision instrument for applying specific torque values to fasteners.

  • Accurate torque measurement
  • Click-type mechanism for feedback
Learn more

Torque Wrench (3/8" Drive)

Larger precision instrument for applying specific torque values to fasteners.

  • Accurate torque measurement
  • Click-type mechanism for feedback
Learn more

Socket Set (Metric)

Comprehensive set of sockets for various bolt and nut sizes on the HVAC system.

  • Variety of socket sizes
  • Durable construction
Learn more

Extension Bars

Used to reach fasteners in recessed or hard-to-access areas.

  • Various lengths for flexibility
  • Secure connection
Learn more

Universal Joint

Allows for angled access when tightening fasteners.

  • Flexible angles
  • Durable construction
Learn more

Torx Socket Set

Set of sockets for specific torx fasteners.

  • Variety of Torx sizes
  • Durable construction
Learn more
Service Procedures

HVAC Compressor Mounting Bolt Torque Procedure

Procedure for properly torquing the bolts securing the HVAC compressor to the engine block.

  • Locate the HVAC compressor mounting bolts.
  • Refer to the vehicle-specific torque specification for the mounting bolts.
  • Using the correct socket size and torque wrench, tighten the bolts in a criss-cross pattern to the specified torque.
  • Verify the torque on all bolts after the initial tightening.
View full procedure

HVAC Condenser Mounting Bolt Torque Procedure

Procedure for properly torquing the bolts securing the HVAC condenser to the vehicle frame.

  • Locate the HVAC condenser mounting bolts.
  • Refer to the vehicle-specific torque specification for the mounting bolts.
  • Using the correct socket size and torque wrench, tighten the bolts to the specified torque.
  • Verify the torque on all bolts after the initial tightening.
View full procedure

HVAC Evaporator Core Housing Bolt Torque Procedure

Procedure for properly torquing the bolts securing the HVAC evaporator core housing.

  • Locate the HVAC evaporator core housing bolts.
  • Refer to the vehicle-specific torque specification for the housing bolts.
  • Using the correct socket size and torque wrench, tighten the bolts to the specified torque.
  • Verify the torque on all bolts after the initial tightening.
View full procedure

HVAC Line Connection Torque Procedure

Procedure for properly torquing the connections on HVAC lines.

  • Locate the HVAC line connections.
  • Refer to the vehicle-specific torque specification for the line connections.
  • Using the correct wrench size and torque wrench, tighten the connections to the specified torque.
  • Verify the torque on all connections after the initial tightening.
View full procedure
Technical Service Bulletins

Reduced AC Cooling Performance Due to Incorrect Compressor Bolt Torque

2020-07-15

Some 2017-2019 Audi Q5 models have reported reduced AC cooling performance due to incorrect tightening of the compressor mounting bolts during assembly.

2017-2019

Resolution: Inspect and tighten all compressor mounting bolts to the specified torque using a calibrated torque wrench. Confirm proper cooling performance after adjustment.

Noise From HVAC Condenser Area

2021-11-20

A rattling noise from the HVAC condenser area may be caused by loose mounting bolts or improperly torqued connections.

2017-2021

Resolution: Inspect and tighten all condenser mounting bolts and connections to the specified torque. Ensure no foreign objects are present around the condenser.

HVAC Evaporator Core Housing Leakage

2022-03-01

Some Audi Q5 models may experience refrigerant leakage from the HVAC evaporator core due to improper housing bolt torque. This can lead to poor HVAC performance and error codes.

2019-2022

Resolution: Verify the correct torque specifications for the evaporator core housing. Remove and inspect the core, tighten all bolts and connections to specification, and then perform a leak test after reassembly.

About the Author

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Alan Montanye - Automotive Technical Specialist
ASE

Alan Montanye

Automotive Technical Specialist

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