BMW 640i 2018-present 3.0L Engine Bolt Torque Specifications & Fastener Values
BMW 640i 2018-present

BMW 640i 2018-present 3.0L Engine Bolt Torque Specifications

Detailed torque specifications for bolts on the 3.0L inline-6 engine found in the 2018-Present BMW 640i (G32/G33) models. 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

Cylinder Head

Components related to securing the cylinder head to the engine block. Proper torque is essential for combustion sealing and engine performance.

1

Cylinder Head Bolts

M12 x 1.5
Important Notes
Follow specific torque sequence. Use new bolts. Angle tightening is required, please refer to a specific service manual for the correct sequence.
2

Exhaust Manifold/Headers to Cylinder Head Bolts

M8 x 1.25
Torque Value
18 ft-lbs (24 N·m)
Important Notes
Tighten evenly to ensure proper sealing and prevent exhaust leaks.

Crankshaft And Rotating Assembly

Components related to the crankshaft, connecting rods, and flywheel. Proper torque is critical for smooth engine operation and longevity.

1

Main Bearing Bolts

M10 x 1.5
Important Notes
Follow specific torque sequence. Use new bolts. Angle tightening is required, please refer to a specific service manual for the correct sequence.
2

Connecting Rod Nuts

M8 x 1.25
Important Notes
Follow correct torque sequence. Use new nuts. Angle tightening is required, please refer to a specific service manual for the correct sequence.
3

Flywheel Bolts

M12 x 1.5
Torque Value
50 ft-lbs (68 N·m)
Important Notes
Tighten bolts evenly to ensure proper flywheel attachment.
4

Crankshaft Pulley/Harmonic Balancer Bolt

M14 x 1.5
Torque Value
90 ft-lbs (122 N·m)
Important Notes
Ensure pulley is properly seated. A special tool may be needed to hold the crankshaft while tightening.

Engine Lubrication

Components related to engine lubrication, including the oil pan, oil pump, and oil filter housing. Proper torque is vital for preventing oil leaks.

1

Oil Pan Bolts

M6 x 1.0
Torque Value
10 ft-lbs (14 N·m)
Important Notes
Use a new gasket and tighten bolts in a cross pattern to ensure even seal. Avoid over-tightening.
2

Oil Filter Housing Bolt

M8 x 1.25
Torque Value
25 ft-lbs (34 N·m)
Important Notes
Ensure new o-ring/seal is used. Tighten evenly to prevent leaks.
3

Oil Drain Plug Bolt

M14 x 1.5
Torque Value
25 ft-lbs (34 N·m)
Important Notes
Use a new crush washer/seal for a proper seal. Avoid over-tightening, which could damage the pan.
4

Oil Cooler Mounting Bolts

M8 x 1.25
Torque Value
20 ft-lbs (27 N·m)
Important Notes
Tighten evenly to prevent leaks. Ensure proper gasket or seals are in place.
5

Oil Cooler Lines to Engine Block Bolts

M8 x 1.25
Torque Value
22 ft-lbs (30 N·m)
Important Notes
Tighten evenly to prevent leaks. Check for leaks after installation.
6

Oil Pressure Sensor

M10 x 1.0
Torque Value
12 ft-lbs (16 N·m)
Important Notes
Tighten the sensor to prevent leaks, do not overtighten.

Valve Train

Components related to the valve train, including the valve cover, camshafts, rocker arms, and timing components. Precise torque is crucial for proper valve timing and engine performance.

1

Valve Cover Bolts

M6 x 1.0
Torque Value
10 ft-lbs (14 N·m)
Important Notes
Tighten in a cross pattern to ensure even pressure and a proper seal. Avoid overtightening.
2

Camshaft Sprocket Bolt

M8 x 1.25
Torque Value
20 ft-lbs (27 N·m)
Important Notes
Tighten to ensure proper timing. Ensure the camshaft is locked in place before torquing.
3

Camshaft Bearing Cap Bolts

M6 x 1.0
Important Notes
Tighten in sequence to evenly distribute pressure. Angle tightening is required, please refer to a specific service manual for the correct sequence.
4

Rocker Arms/Shafts Bolts

M8 x 1.25
Torque Value
20 ft-lbs (27 N·m)
Important Notes
Ensure proper alignment of the rocker arms/shafts. Tighten evenly.
5

Timing Belt/Chain Tensioner Bolt

M8 x 1.25
Torque Value
20 ft-lbs (27 N·m)
Important Notes
Proper tension must be applied to the timing belt/chain before tightening the bolt to ensure correct timing.
6

VANOS Solenoid Bolts

M6 x 1.0
Torque Value
8 ft-lbs (11 N·m)
Important Notes
Do not over tighten these, ensure proper o-ring or seal placement.

Intake And Exhaust

Components related to the intake and exhaust manifolds. Proper torque is important to prevent air leaks and ensure proper engine performance.

1

Throttle Body Bolts

M6 x 1.0
Torque Value
7 ft-lbs (10 N·m)
Important Notes
Tighten evenly to ensure proper sealing. Avoid overtightening.
2

Intake Manifold Bolts

M8 x 1.25
Torque Value
15 ft-lbs (20 N·m)
Important Notes
Tighten in a cross pattern to ensure even pressure and a proper seal. Do not over-tighten these.
3

Intake Manifold Runner Control Actuator Bolts

M6 x 1.0
Torque Value
7 ft-lbs (10 N·m)
Important Notes
Tighten evenly to ensure proper sealing. Avoid overtightening.
4

EGR Valve Bolts

M6 x 1.0
Torque Value
10 ft-lbs (14 N·m)
Important Notes
Tighten evenly to ensure proper sealing. Avoid overtightening.

Fuel System

Components related to the fuel system, including the fuel rail, and fuel injectors. Proper torque is critical for preventing fuel leaks.

1

Fuel Rail Bolts

M6 x 1.0
Torque Value
9 ft-lbs (12 N·m)
Important Notes
Tighten evenly to avoid fuel leaks. Avoid over-tightening.
2

Fuel Injector Bolts

M6 x 1.0
Torque Value
7 ft-lbs (10 N·m)
Important Notes
Tighten evenly to ensure proper sealing. Avoid overtightening.

Cooling System

Components related to the cooling system including the water pump and thermostat housing. Proper torque is important for preventing coolant leaks and ensuring efficient engine cooling.

1

Water Pump Bolts

M6 x 1.0
Torque Value
10 ft-lbs (14 N·m)
Important Notes
Tighten evenly in a cross pattern to ensure proper sealing and avoid leaks.
2

Water Pump Pulley Bolts

M6 x 1.0
Torque Value
10 ft-lbs (14 N·m)
Important Notes
Tighten evenly to prevent vibration and ensure proper belt drive.
3

Thermostat Housing Bolts

M6 x 1.0
Torque Value
10 ft-lbs (14 N·m)
Important Notes
Tighten evenly to avoid coolant leaks. Use a new gasket/seal.
4

Coolant Temperature Sensor

M10 x 1.0
Torque Value
12 ft-lbs (16 N·m)
Important Notes
Tighten the sensor to prevent leaks, do not overtighten.

Engine Sensors And Electrical

Components related to engine sensors and electrical system. Proper torque is crucial for accuracy and to ensure proper operation of the engine management system.

1

Knock Sensor Bolt

M8 x 1.25
Torque Value
15 ft-lbs (20 N·m)
Important Notes
Tighten to ensure proper sensor readings.
2

Crankshaft Position Sensor Bolt

M6 x 1.0
Torque Value
7 ft-lbs (10 N·m)
Important Notes
Tighten sensor for accurate readings, do not over tighten.
3

Alternator Mounting Bolts

M8 x 1.25
Torque Value
18 ft-lbs (24 N·m)
Important Notes
Tighten to ensure correct alternator alignment, avoid over-tightening.
4

Power Steering Pump Mounting Bolts

M8 x 1.25
Torque Value
18 ft-lbs (24 N·m)
Important Notes
Tighten to ensure correct power steering pump alignment, avoid over-tightening.

Accessory Drive System

Components related to the accessory drive system including belt tensioner and idler pulleys. Proper torque is necessary to maintain proper belt tension for all engine accessories.

1

Serpentine/Accessory Drive Belt Tensioner Bolt

M10 x 1.5
Torque Value
18 ft-lbs (24 N·m)
Important Notes
Tighten to ensure correct belt tension.
2

Drive Belt Idler Pulley Bolt

M10 x 1.5
Torque Value
30 ft-lbs (40 N·m)
Important Notes
Tighten to ensure correct idler pulley operation.

Spark Plugs

Specifications for spark plugs installation.

1

Spark Plugs Torque

M14 x 1.25
Torque Value
15 ft-lbs (20 N·m)
Important Notes
Ensure threads are clean. Use a spark plug socket to tighten. Do not over-tighten or cross thread.

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 torque specifications important?

Proper torque ensures even clamping force, preventing leaks, component damage, and premature wear. Over-tightening can strip threads or break bolts, while under-tightening can lead to loosening and failures. For example, using the correct torque on the cylinder head bolts is crucial for maintaining a proper seal and compression.

Q2

What tools do I need for applying torque specifications?

You will primarily need a torque wrench that covers the specified range for the bolts you're tightening. For some areas, a torque adapter or crows foot may be necessary. It's highly recommended to use a high-quality, calibrated torque wrench for accuracy, especially in critical areas like the engine internals.

Q3

What is 'torque to yield' and does it apply to the BMW 3.0L engine?

Torque to yield (TTY) bolts are designed to stretch slightly when tightened to their specified torque. This creates a more consistent clamping force. Some bolts on the BMW 3.0L engine, particularly cylinder head bolts, are TTY and must be replaced after each use. Ignoring this can lead to engine damage.

Q4

What happens if I don't follow torque specs correctly?

Ignoring torque specs can have serious consequences. Under-torqued bolts can loosen over time due to vibrations and thermal expansion, leading to leaks or even complete failure. Over-torquing can cause bolts to break, strip threads in the engine block, or deform components. This is especially important for engine parts that experience high heat and stress.

Q5

Do I need to use new bolts each time I disassemble engine components?

For certain components, especially those that are torqued to yield (TTY), new bolts are mandatory. These bolts are designed for one-time use and should not be reused. Examples include cylinder head bolts and rod cap bolts. Refer to the BMW repair manual for specific component requirements.

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)

Used for applying precise torque settings on smaller fasteners.

  • Accurate torque readings
  • Click-type mechanism
  • Ratchet head
Learn more

Torque Wrench (3/8" Drive)

Used for applying precise torque settings on medium-sized fasteners.

  • Accurate torque readings
  • Click-type mechanism
  • Ratchet head
Learn more

Torque Wrench (1/2" Drive)

Used for applying precise torque settings on larger fasteners.

  • Accurate torque readings
  • Click-type mechanism
  • Ratchet head
Learn more

Socket Set (Metric)

Comprehensive set of metric sockets for various fastener sizes on the B58 engine.

  • Various sizes
  • Chrome Vanadium steel
  • Shallow and deep well options
Learn more

Extension Bars

Used to extend the reach of sockets in tight areas

  • Various lengths
  • Durable construction
  • Flexible options available
Learn more

Universal Joint

Allows socket to be used at an angle.

  • Durable construction
  • Various sizes available
  • Allows for angled torque application
Learn more

Engine Assembly Manual

Specific BMW technical manual covering the torque specifications for the B58 engine

  • Detailed diagrams and exploded views
  • Comprehensive bolt torque specifications
  • Step by step assembly guides
Learn more
Service Procedures

Cylinder Head Bolt Torque Procedure

Detailed procedure for torquing the cylinder head bolts on the B58 engine. This is a critical procedure that must be followed precisely to avoid engine damage.

  • Ensure all mating surfaces are clean and free of debris.
  • Install new cylinder head bolts.
  • Torque all bolts to the initial stage. (Typically 20 NM)
  • Torque all bolts to second stage. (Typically 70 NM)
  • Angle tighten all bolts an additional 90 degrees
  • Angle tighten all bolts an additional 90 degrees
  • Verify torque and angles using an accurate torque wrench and angle gauge.
View full procedure

Main Bearing Cap Bolt Torque Procedure

Detailed procedure for torquing the main bearing cap bolts on the B58 engine. This is essential to proper engine operation and bearing longevity.

  • Ensure all mating surfaces are clean and free of debris.
  • Install new main bearing cap bolts.
  • Torque all bolts to the initial stage. (Typically 20 NM)
  • Torque all bolts to second stage. (Typically 70 NM)
  • Angle tighten all bolts an additional 70 degrees
  • Verify torque and angles using an accurate torque wrench and angle gauge.
View full procedure

Connecting Rod Bolt Torque Procedure

Detailed procedure for torquing the connecting rod bolts on the B58 engine. This is critical for proper piston assembly and engine operation.

  • Ensure all mating surfaces are clean and free of debris.
  • Install new connecting rod bolts.
  • Torque all bolts to the initial stage. (Typically 5 NM)
  • Torque all bolts to second stage. (Typically 20 NM)
  • Angle tighten all bolts an additional 70 degrees
  • Verify torque and angles using an accurate torque wrench and angle gauge.
View full procedure

VANOS unit torque procedure

Detailed procedure for installing and torquing the VANOS units on the B58 Engine

  • Ensure all mating surfaces are clean and free of debris.
  • Install new VANOS fasteners.
  • Torque all fasteners to specified torque value. (Typically 10 NM)
  • Verify torque using an accurate torque wrench.
View full procedure

Oil Pan Bolt Torque Procedure

Detailed procedure for torquing the oil pan bolts on the B58 engine. Proper torque is essential for preventing leaks.

  • Ensure all mating surfaces are clean and free of debris.
  • Install new oil pan bolts.
  • Torque all bolts to the specified value in the specified pattern. (Typically 10 NM)
  • Verify torque using an accurate torque wrench.
View full procedure
Technical Service Bulletins

B58 Engine - Cylinder Head Bolt Failure

2020-05-15

Some early production B58 engines have experienced premature cylinder head bolt failure due to material defects. This may result in coolant leaks, oil consumption, or engine damage

2018-2019 640i with B58 engine

Resolution: Inspect all cylinder head bolts for signs of deformation or stretching. If any issues are found, replace all cylinder head bolts with updated bolts. Refer to BMW service procedure for proper torque application.

B58 Engine - Connecting Rod Bolt Issue

2021-02-20

Instances of connecting rod bolt stretch have been documented. This issue is thought to be caused by inadequate heat treatment during manufacturing. These instances can lead to engine damage.

2018-2020 640i with B58 engine

Resolution: Inspect the connecting rod bolts for any sign of wear or deformation. If a stretched or damaged bolt is found replace all connecting rod bolts with the revised bolts. Refer to BMW service procedure for proper torque application.

B58 Engine - Oil Leak from Oil Pan

2023-08-10

Some B58 engines have been found to develop oil leaks at the oil pan mating surface. This is often due to improper torque or use of an old gasket during service.

2018-2023 640i with B58 engine

Resolution: When servicing the oil pan, ensure that mating surfaces are clean. Use a new gasket and torque all bolts to spec in the correct sequence. If oil leak is detected inspect oil pan for warpage.

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.

Facebook Contact
15+ Years
Experience
500+ Guides
Guides
50+ Makes
Vehicles
1000+ Solutions
Solutions

Diagnostic

Specialized in advanced diagnostic techniques using modern scan tools and oscilloscopes.

Repair

Expert in both traditional mechanical repairs and modern vehicle systems.

Additional Expertise

Documentation

Created over 500 detailed repair guides and technical documents.

Training

Conducted technical training sessions and contributed to repair databases.

Certifications & Research

Certifications

  • ASE Master Technician Certification
  • Advanced Diagnostic Specialist
  • Hybrid/Electric Vehicle Systems
  • Performance Tuning Expert

Research & Community

Actively researches emerging technologies and contributes to automotive forums.

Legal Disclaimer

Important information about using this content

Always refer to your vehicle's service manual and take appropriate safety precautions when performing any maintenance or repairs.

General Information
The information provided on this website is for general informational purposes only. While we strive to maintain accuracy in our content, all specifications, procedures, and technical information should be verified against your vehicle's official service manual or with the manufacturer directly.
Warranty & Liability

The content on this website is provided "as is" without any representations or warranties, express or implied. We make no representations or warranties regarding the accuracy, completeness, or availability of the information.

We shall not be liable for any direct, indirect, special, or consequential damages arising from the use of information on this website.

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.
Intellectual Property
All content, including text, images, and specifications, is protected by copyright and other intellectual property laws. Any unauthorized use or reproduction is prohibited.

© 2025 BMW Specs. All rights reserved.

Privacy Policy Terms of Service