Acura NSX 2016-present 3.5L Engine Bolt Torque Specifications
Comprehensive guide to torque specifications for various bolts on the 3.5L engine found in the 2016-present Acura NSX. Includes cylinder head bolts, main bearing cap bolts, and other crucial fasteners.
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
Engine block and cylinder head
Components that secure the cylinder head to the engine block, ensuring proper combustion and preventing engine damage.
1 Cylinder Head Bolts
M12 x 1.5
Cylinder Head Bolts
M12 x 1.5Torque Value
Important Notes
2 Engine Block Main Bearing Bolts
M14 x 2.0
Engine Block Main Bearing Bolts
M14 x 2.0Torque Value
Important Notes
3 Engine Block Side Bolts
M10 x 1.5
Engine Block Side Bolts
M10 x 1.5Torque Value
Important Notes
Timing chain and gears
Components that maintain proper timing chain tension and prevent engine damage.
1 Timing Chain Tensioner Bolts
M8 x 1.25
Timing Chain Tensioner Bolts
M8 x 1.25Torque Value
Important Notes
2 Timing Chain Guide Bolts
M6 x 1.0
Timing Chain Guide Bolts
M6 x 1.0Torque Value
Important Notes
Oil and water systems
Components that secure the oil pan and water pump to the engine block, preventing oil and coolant leaks.
1 Oil Pan Bolts
M10 x 1.5
Oil Pan Bolts
M10 x 1.5Torque Value
2 Water Pump Bolts
M12 x 1.5
Water Pump Bolts
M12 x 1.5Torque Value
Intake and exhaust systems
Components that secure the intake and exhaust manifolds to the engine block, preventing vacuum and exhaust leaks.
1 Intake Manifold Bolts
M10 x 1.5
Intake Manifold Bolts
M10 x 1.5Torque Value
Important Notes
2 Exhaust Manifold Bolts
M12 x 1.5
Exhaust Manifold Bolts
M12 x 1.5Torque Value
Important Notes
Accessory belt and pulleys
Components that maintain proper accessory belt tension and prevent belt failure.
1 Accessory Belt Tensioner Bolts
M8 x 1.25
Accessory Belt Tensioner Bolts
M8 x 1.25Torque Value
2 Alternator Bolts
M10 x 1.5
Alternator Bolts
M10 x 1.5Torque Value
Important Notes
Critical safety-critical fasteners
Components that secure the engine to the engine mounts and prevent engine movement, which can cause damage or injury.
1 Engine Mount Bolts
M14 x 2.0
Engine Mount Bolts
M14 x 2.0Torque Value
2 Cylinder Head Studs
M12 x 1.5
Cylinder Head Studs
M12 x 1.5Troubleshooting 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 Why are precise torque specifications important for the 3.5L engine in the Acura NSX?
Why are precise torque specifications important for the 3.5L engine in the Acura NSX?
Accurate torque ensures proper clamping force, preventing leaks, component failure, and damage to the aluminum engine block. Under-tightening can lead to leaks or loosening, while over-tightening can stretch or break bolts and damage threads. The high-performance nature of the NSX engine requires these tolerances to be precise.
Q2 What type of torque wrench should I use when working on the 3.5L engine?
What type of torque wrench should I use when working on the 3.5L engine?
A calibrated, click-type torque wrench is highly recommended. Digital torque wrenches offer greater precision but can be more expensive. Ensure the wrench is within its calibration period and has a torque range suitable for the bolts you're working with. Avoid using beam-style wrenches, as they are generally less precise.
Q3 Do I need to use new bolts when reassembling the 3.5L engine?
Do I need to use new bolts when reassembling the 3.5L engine?
While not all bolts require replacement every time they are removed, many torque-to-yield (TTY) or stretch bolts should be replaced with new ones as they are designed to deform slightly when tightened and will not properly clamp if reused. The specific NSX service manual should be consulted for the specific components. Fasteners such as those for the connecting rod caps, cylinder head bolts and main bearing bolts are examples of bolts that should always be replaced.
Q4 What is the difference between torque specification and torque angle (or torque plus angle)?
What is the difference between torque specification and torque angle (or torque plus angle)?
Some fasteners are tightened to a specific torque value and then a defined additional angle to ensure the proper stretch of the fastener. This is common for cylinder head bolts. A torque spec only specifies an initial tightening force but may not produce the proper clamping force in some applications. A torque angle (torque plus angle) method provides the precise level of stretch of the fastener by an angle reading after the torque specification. Improper use of torque angle could result in significant damage. Always check the repair manual.
Q5 Where can I find the most accurate torque specifications for my specific 2016-present Acura NSX 3.5L engine?
Where can I find the most accurate torque specifications for my specific 2016-present Acura NSX 3.5L engine?
The most accurate source is the official Acura NSX service manual for your specific model year. Online databases may provide specifications but should always be cross-referenced with the official manual. Use caution when using third-party or unverified sources and always defer to the manufacturer guidelines first.
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 calibrated torque wrench with a 1/2" drive is essential for accurately tightening bolts to specified torque values. Digital models offer precise readings.
- Calibrated for accuracy
- 1/2" drive compatibility
- Wide torque range
Torque Wrench (3/8" Drive)
A smaller 3/8" drive torque wrench is useful for tighter spaces and lower torque specifications.
- Calibrated for accuracy
- 3/8" drive compatibility
- Suitable for lower torque applications
Socket Set (Metric)
A comprehensive metric socket set is necessary to fit the various bolt head sizes found on the 3.5L engine.
- Various sizes
- 6-point design preferred for better grip
- Durable construction
Extension Bars
Extension bars allow access to recessed bolts that may be hard to reach directly with the torque wrench.
- Various lengths
- 1/2" and 3/8" drive options
- Durable construction
Universal Joint
A universal joint socket adapter provides flexibility when tightening bolts at an angle.
- Allows for angled tightening
- 1/2" and 3/8" drive options
- Durable construction
Service Procedures
Cylinder Head Bolt Torque Procedure
Detailed instructions for correctly tightening the cylinder head bolts on the 3.5L engine to prevent leaks and ensure proper sealing.
- Clean all bolt threads and mating surfaces.
- Apply a thin film of engine oil to bolt threads.
- Tighten all bolts to the first torque specification in the sequence.
- Tighten all bolts to the second torque specification in the sequence.
- Use a torque angle gauge and perform the final angle tightening step.
- Verify final torque.
Main Bearing Cap Bolt Torque Procedure
Procedure for tightening the main bearing cap bolts, crucial for crankshaft support and longevity.
- Clean all bolt threads and mating surfaces.
- Apply a thin film of engine oil to bolt threads.
- Tighten all bolts to the first torque specification in the sequence.
- Tighten all bolts to the second torque specification in the sequence.
- Verify final torque.
Connecting Rod Bolt Torque Procedure
Procedure for tightening the connecting rod cap bolts.
- Clean all bolt threads and mating surfaces.
- Apply a thin film of engine oil to bolt threads.
- Tighten all bolts to the first torque specification in the sequence.
- Tighten all bolts to the second torque specification in the sequence.
- Verify final torque.
Intake Manifold Bolt Torque Procedure
Procedure for tightening the intake manifold bolts to ensure proper sealing and prevent vacuum leaks.
- Clean all bolt threads and mating surfaces.
- Tighten all bolts to the specified torque in a criss-cross pattern.
- Verify final torque.
Exhaust Manifold Bolt Torque Procedure
Procedure for tightening the exhaust manifold bolts.
- Clean all bolt threads and mating surfaces.
- Tighten all bolts to the specified torque in a criss-cross pattern.
- Verify final torque.
Technical Service Bulletins
Engine Misfire Due to Improperly Torqued Cylinder Head Bolts
2017-03-15A technical service bulletin addressing instances of engine misfires in certain early NSX models related to insufficiently torqued cylinder head bolts.
Resolution: Re-torque cylinder head bolts to the updated specifications, following the correct torque sequence and angle tightening procedure.
Updated Torque Specification for Main Bearing Cap Bolts
2018-11-20A revised torque specification has been issued for the main bearing cap bolts to improve reliability and prevent potential issues.
Resolution: Tighten main bearing cap bolts according to the new torque specifications, ensuring all bolts are properly cleaned and lubricated.
Oil Leakage at the Intake Manifold Interface
2020-07-01Cases of oil leakage due to improperly torqued intake manifold bolts.
Resolution: Inspect the intake manifold sealing surface. If no damage is present, tighten intake manifold bolts to the specified torque in a criss-cross pattern.
About the Author
Expert automotive knowledge and experience
'/%3E%3Cpath d='M60 30a20 20 0 1 1 0 40 20 20 0 0 1 0-40zm0 45c16.5 0 30 7.5 30 16.8V100H30v-8.2c0-9.3 13.5-16.8 30-16.8z' fill='%23404040'/%3E%3C/svg%3E)
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
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.