BMW Vehicle Models i8 2014-2020 Torque Specifications
BMW Vehicle Models i8 2014-2020

BMW Vehicle Models i8 2014-2020 Torque Specifications

Complete BMW Vehicle Models i8 2014-2020 torque specifications guide. Includes factory-specified torque values, torque sequences, and technical specifications for all components including body, brakes, drivetrain, electrical, emissions sensors, fuel, exhaust, HVAC, and suspension. Essential information for proper assembly and maintenance.

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

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Torque Calculator

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1.5l Hybrid Engine

Torque specifications for 1.5L-HYBRID Engine

Cylinder Head

1

Cylinder Head Bolts

M10 x 1.25
Torque Specification
1. 23 ft-lbs (31 N·m) 2. 90°
Important Notes
Tighten in specified sequence, then angle tighten
2

Valve Cover Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Tighten evenly.
3

Rocker Arms/Shafts Bolts

M8 x 1.25
Torque Specification
15 ft-lbs (20 N·m)
Important Notes
Tighten evenly.
4

Camshaft Sprocket Bolt

M10 x 1.25
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Tighten to specified torque.
5

Camshaft Position Sensor Bolt

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Tighten evenly.
6

Variable Valve Timing (VVT) Solenoid Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Tighten evenly.

Engine Block

1

Main Bearing Bolts

M12 x 1.5
Torque Specification
48 ft-lbs (65 N·m)
Important Notes
Tighten in specified sequence.
2

Connecting Rod Nuts

M9 x 1.0
Torque Specification
22 ft-lbs (30 N·m)
Important Notes
Tighten evenly.
3

Oil Pan Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Tighten evenly in a criss-cross pattern.
4

Oil Drain Plug Bolt

M14 x 1.5
Torque Specification
22 ft-lbs (30 N·m)
Important Notes
Use a new crush washer.
5

Oil Filter Housing Bolt

M8 x 1.25
Torque Specification
5 ft-lbs (7 N·m)
Important Notes
Hand-tight, do not over tighten. Estimated value. Actual spec is hand tight.
6

Crankshaft Position Sensor Bolt

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Tighten evenly.
7

Oil Pressure Sensor Bolt

M6 x 1.0
Torque Specification
15 ft-lbs (20 N·m)
Important Notes
Tighten evenly.

Intake System

1

Intake Manifold Bolts

M8 x 1.25
Torque Specification
15 ft-lbs (20 N·m)
Important Notes
Tighten evenly in a criss-cross pattern.
2

Throttle Body Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Tighten evenly.
3

EGR Valve Bolts

M6 x 1.0
Torque Specification
15 ft-lbs (20 N·m)
Important Notes
Tighten evenly.
4

Intake Air Temperature (IAT) Sensor Bolt

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Tighten evenly.

Exhaust System

1

Exhaust Manifold/Headers Bolts

M8 x 1.25
Torque Specification
23 ft-lbs (31 N·m)
Important Notes
Tighten in specified sequence.

Fuel System

1

Fuel Rail Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Tighten evenly.
2

Fuel Injector Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Tighten evenly.

Cooling System

1

Water Pump Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Tighten evenly.
2

Water Pump Pulley Bolts

M8 x 1.25
Torque Specification
15 ft-lbs (20 N·m)
Important Notes
Tighten evenly.
3

Thermostat Housing Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Tighten evenly.
4

Coolant Temperature Sensor Bolt

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Tighten evenly.

Ignition System

1

Spark Plugs

M14 x 1.25
Torque Specification
22 ft-lbs (30 N·m)
Important Notes
Use a torque wrench designed for spark plugs. Use anti-seize on plug threads.
2

Ignition Coil Bolt

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Tighten evenly.

Ancillary Components

1

Crankshaft Pulley/Harmonic Balancer Bolt

M14 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Tighten to specified torque.
2

Serpentine/Accessory Drive Belt Tensioner Bolt

M10 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Tighten to specified torque.
3

Drive Belt Idler Pulley Bolt

M10 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Tighten to specified torque.
4

Alternator Mounting Bolts

M10 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Tighten to specified torque.
5

A/C Compressor Mounting Bolts

M10 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Tighten to specified torque.
6

Knock Sensor Bolt

M8 x 1.25
Torque Specification
15 ft-lbs (20 N·m)
Important Notes
Tighten to specified torque.

Transmission Interface

1

Flywheel Bolts

M10 x 1.25
Torque Specification
48 ft-lbs (65 N·m)
Important Notes
Tighten in a star pattern.

6hp Transmission

Torque specifications for 6hp Transmission

Transmission Mounting

1

Transmission Mounting Bolts

M12 x 1.75
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Ensure bolts are tightened evenly. Verify correct bolt length.

Oil Pan

1

Transmission Oil Pan Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Tighten bolts in a cross pattern to ensure even gasket compression. Do not overtighten as this can cause leaks.

Drain And Fill Plugs

1

Transmission Fill Plug

M22 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Use a new sealing washer and ensure it is properly seated.
2

Transmission Drain Plug

M18 x 1.5
Torque Specification
22 ft-lbs (30 N·m)
Important Notes
Use a new sealing washer and ensure it is properly seated.

Mechatronic Unit

1

Mechatronic Unit Bolts

M6 x 1.0
Torque Specification
6 ft-lbs (8 N·m)
Important Notes
Tighten bolts in a specific sequence as indicated in the repair manual. Low torque value to avoid damage. Estimated torque value. Do not overtighten, as this may cause damage to the valve body and/or cause a leak.

Cooler Lines

1

Transmission Cooler Line Fittings/Bolts

M14 x 1.5
Torque Specification
15 ft-lbs (20 N·m)
Important Notes
Use new crush washers or o-rings. Ensure proper line alignment. Estimated torque value.

Output Flange

1

Transmission Output Flange Bolt/Nut

M10 x 1.5
Torque Specification
55 ft-lbs (75 N·m)
Important Notes
Use threadlocker when installing if specified in the service manual. Always check the service manual for specific procedures as torque values can vary. Ensure bolts/nuts are properly seated on the flange.

Adapter Plate

1

Transmission Adapter Plate Bolts

M10 x 1.5
Torque Specification
26 ft-lbs (35 N·m)
Important Notes
Tighten bolts evenly to ensure proper alignment. Use a threadlocker if specified by the service manual. Estimated torque value.

Body

Torque specifications for Body

Wheels And Tires

1

Wheel Lug Nuts

M14 x 1.5
Torque Specification
88 ft-lbs (120 N·m)
Important Notes
Tighten in a star pattern to ensure even clamping force.

Fuel System

1

Fuel Tank Strap Bolts

M8 x 1.25
Torque Specification
22 ft-lbs (30 N·m)
Important Notes
Ensure proper alignment before tightening.
2

Fuel Filler Neck Bolts

M6 x 1.0
Torque Specification
22 ft-lbs (30 N·m)
Important Notes
Ensure proper seal alignment during installation.

Body Panels

1

Body Panel Fasteners (Small)

M6 x 1.0
Torque Specification
10 ft-lbs (14 N·m)
Important Notes
Estimated value. Check specific service manual. Do not over tighten.
2

Body Panel Fasteners (Large)

M8 x 1.25
Torque Specification
22 ft-lbs (30 N·m)
Important Notes
Estimated value. Check specific service manual. Do not over tighten.
3

Door Hinge Bolts

M10 x 1.5
Torque Specification
30 ft-lbs (40 N·m)
Important Notes
Estimated value. Check specific service manual.
4

Door Latch/Striker Bolts

M8 x 1.25
Torque Specification
11 ft-lbs (15 N·m)
Important Notes
Estimated value. Check specific service manual.
5

Hood Hinge Bolts

M8 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Estimated value. Check specific service manual.
6

Hood Latch/Striker Bolts

M6 x 1.0
Torque Specification
11 ft-lbs (15 N·m)
Important Notes
Estimated value. Check specific service manual.
7

Bumper Mounting Bolts

M8 x 1.25
Torque Specification
20 ft-lbs (27 N·m)
Important Notes
Estimated value. Check specific service manual. Do not over tighten.

Interior Components

1

Seat Mounting Bolts

M10 x 1.5
Torque Specification
44 ft-lbs (60 N·m)
Important Notes
Critical for safety. Check specific service manual.
2

Seatbelt Mounting Bolts

M10 x 1.5
Torque Specification
44 ft-lbs (60 N·m)
Important Notes
Critical for safety. Check specific service manual.
3

Interior Trim Mounting Bolts/Screws

M5 x 0.8
Torque Specification
9 ft-lbs (12 N·m)
Important Notes
Estimated value. Check specific service manual. Do not over tighten.

Exterior Components

1

Mirror Mounting Bolts/Fasteners

M6 x 1.0
Torque Specification
11 ft-lbs (15 N·m)
Important Notes
Estimated value. Check specific service manual. Do not over tighten.
2

Headlight/Taillight Mounting Bolts

M6 x 1.0
Torque Specification
11 ft-lbs (15 N·m)
Important Notes
Estimated value. Check specific service manual. Do not over tighten.

Brakes

Torque specifications for Brakes

Caliper Mounting

1

Brake Caliper Bolts

M12 x 1.75
Torque Specification
80 ft-lbs (108 N·m)
Important Notes
Secures the caliper to the mounting bracket. Ensure bolts are tightened evenly. Use new bolts when servicing.
2

Brake Caliper Mounting Bracket Bolts

M14 x 1.5
Torque Specification
90 ft-lbs (122 N·m)
Important Notes
Fastens the mounting bracket to the wheel knuckle or suspension. Ensure proper seating before tightening. Use new bolts when servicing.

Rotor And Wheel

1

Brake Disc/Drum Retaining Bolts

M8 x 1.25
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Secures the brake rotor to the hub prior to wheel installation. These bolts are not structural and do not need high torque. Note: This torque is an estimate.
2

Wheel Lug Nuts

M14 x 1.5
Torque Specification
88 ft-lbs (120 N·m)
Important Notes
Attaches the wheel to the hub. Tighten in a star pattern to ensure even clamping. Over-tightening can damage the rotor and/or hub.

Brake Pads

1

Brake Pad Retaining Pin/Bolt/Clip

M8 x 1.25
Torque Specification
20 ft-lbs (27 N·m)
Important Notes
Retains the brake pads within the caliper. This torque value is an estimate. Do not over-tighten, as these are very easily stripped. Replace retaining hardware if it is old or damaged

Brake Lines

1

Brake Line/Hose Banjo Bolt

M10 x 1.0
Torque Specification
25 ft-lbs (34 N·m)
Important Notes
Connects brake lines to the calipers. Always use new crush washers. This torque value is an estimate.
2

Brake Bleeder Screw

M7 x 1.0
Torque Specification
10 ft-lbs (14 N·m)
Important Notes
Secures the bleeder screw to the caliper. Do not over-tighten. This torque value is an estimate.

Abs System

1

ABS Sensor Bolt

M6 x 1.0
Torque Specification
8 ft-lbs (11 N·m)
Important Notes
Mounts the ABS sensor to the hub or knuckle. Do not over-tighten. This torque value is an estimate.

Drivetrain

Torque specifications for Drivetrain

Flywheel And Clutch

1

Flywheel Bolts

M12 x 1.25
Torque Specification
48 ft-lbs (65 N·m)
Important Notes
Tighten bolts in a star pattern to ensure even clamping pressure. It is recommended to use new bolts.
2

Clutch Pressure Plate Bolts

M8 x 1.25
Torque Specification
23 ft-lbs (31 N·m)
Important Notes
Tighten bolts in a star pattern to ensure even clamping pressure. Ensure clutch disc is properly aligned before torquing. Estimated value, refer to manufacturer's specific torque spec for your clutch model.

Transmission

1

Transmission Bellhousing Bolts

M10 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Tighten the bellhousing bolts in a crisscross pattern to ensure even clamping. Ensure proper alignment of the bellhousing and engine block.
2

Transmission Mounting Bolts

M12 x 1.75
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Ensure proper alignment before tightening to prevent any stress on the mounts.
3

Transmission Oil Pan Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Use a crisscross pattern to tighten the oil pan bolts. Over-tightening can cause leaks. Use a new gasket when reassembling.
4

Transmission Drain and Fill Plugs

M18 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Use new sealing washers or O-rings to ensure a leak-proof seal. Do not over-tighten to prevent damaging the housing.

Driveshaft And Axles

1

Drive Axle/Half Shaft Bolts

M10 x 1.5
Torque Specification
74 ft-lbs (100 N·m)
Important Notes
Ensure proper alignment of the axle to the transmission flange or hub before tightening the bolts. Tighten in a star pattern.
2

CV Joint/Axle Nut

M24 x 1.5
Torque Specification
180 ft-lbs (244 N·m)
Important Notes
This nut is critical for wheel bearing preload. Always use a new nut when reassembling. This is a high torque fastener.
3

Propeller/Drive Shaft Bolts

M10 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Tighten the bolts in a star pattern to ensure even clamping pressure. Ensure proper driveshaft alignment.

Differential

1

Differential Drain/Fill Plug

M18 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Use new sealing washers or O-rings to ensure a leak-proof seal. Do not over-tighten to prevent damaging the housing.
2

Differential Mounting Bolts

M12 x 1.75
Torque Specification
74 ft-lbs (100 N·m)
Important Notes
Ensure proper alignment of the differential to the chassis or subframe before tightening the bolts. Some mounts may need shimming for correct alignment.

Starter Motor

1

Starter Motor Mounting Bolts

M10 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Ensure the starter motor is aligned correctly with the engine block. Do not over-tighten these bolts.

Electrical

Torque specifications for Electrical

Ignition System

1

Ignition Coil Mounting Bolt

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Ensure the coil is seated correctly before tightening. Do not overtighten.

Starting Charging System

1

Starter Motor Mounting Bolt

M10 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Ensure proper starter motor alignment before tightening.
2

Alternator Mounting Bolt

M10 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Check belt alignment after mounting the alternator.
3

Battery Terminal Nut

M8 x 1.25
Torque Specification
6 ft-lbs (8 N·m)
Important Notes
Do not overtighten. This is an estimated value. Check battery or manufacturer for more precise specs.

Grounding System

1

Battery Ground Strap Bolt

M8 x 1.25
Torque Specification
18 ft-lbs (24 N·m)
Important Notes
Ensure the ground contact surface is clean and free of corrosion.

High Voltage System

1

High Voltage Battery Module Mounting Bolt

M8 x 1.25
Torque Specification
22 ft-lbs (30 N·m)
Important Notes
High voltage system component. Ensure all safety procedures are followed. This is an estimated value.
2

High Voltage Junction Box Mounting Bolt

M6 x 1.0
Torque Specification
15 ft-lbs (20 N·m)
Important Notes
High voltage component. Check for proper grounding.
3

Electric Motor Mounting Bolt

M12 x 1.75
Torque Specification
40 ft-lbs (54 N·m)
Important Notes
Ensure the motor is aligned correctly with the transmission before tightening.
4

Power Electronics Module Mounting Bolt

M8 x 1.25
Torque Specification
22 ft-lbs (30 N·m)
Important Notes
Ensure proper heat dissipation is considered.

Sensor System

1

Sensor Mounting Bolt (ABS, Wheel Speed, Crank/Cam Position)

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Do not overtighten, as sensors can be fragile.

Wiring Harness System

1

Wiring Harness Connector Bolt

M5 x 0.8
Torque Specification
4 ft-lbs (5 N·m)
Important Notes
Do not overtighten. Check BMW TIS for precise specs. This is an estimated value.

Control Units

1

Engine Control Unit (ECU) Mounting Bolt

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Ensure proper grounding when securing.

Emissions Sensors

Torque specifications for Emissions_sensors

Egr System

1

EGR Valve Mounting Bolts

M8 x 1.25
Torque Specification
15 ft-lbs (20 N·m)
Important Notes
Ensure a clean and flat mounting surface for proper sealing. Always use a new gasket or seal.

Exhaust Manifold

1

Exhaust Manifold to Cylinder Head Bolts

M8 x 1.25
Torque Specification
23 ft-lbs (31 N·m)
Important Notes
Use a new exhaust manifold gasket. Torque in a criss-cross sequence to ensure even pressure. May need multiple passes to reach final torque.

Exhaust System

1

Exhaust Pipe to Exhaust Manifold/Headers Bolts

M10 x 1.5
Torque Specification
23 ft-lbs (31 N·m)
Important Notes
Ensure that a new gasket or seal is installed. Uneven torque can cause leaks.
2

Catalytic Converter to Exhaust Pipe Bolts

M10 x 1.5
Torque Specification
23 ft-lbs (31 N·m)
Important Notes
Always use new gaskets to prevent leaks. Over-torquing can damage the mounting flanges.
3

Muffler to Exhaust Pipe Bolts

M10 x 1.5
Torque Specification
23 ft-lbs (31 N·m)
Important Notes
Use new gaskets when available, Over-torquing may cause damage. May need multiple passes to reach final torque.

Oxygen Sensors

1

Oxygen (Lambda) Sensor

M18 x 1.5
Torque Specification
26 ft-lbs (35 N·m)
Important Notes
Use anti-seize compound on threads, if recommended. Do not over-tighten to avoid damaging the sensor.

Nox Sensors

1

NOx Sensor Mounting Bolts

M6 x 1.0
Torque Specification
6.5 ft-lbs (9 N·m)
Important Notes
Do not overtighten these, or the sensor may crack. Sensor may have an integrated seal - confirm before replacing.

Differential Pressure Sensors

1

Differential Pressure Sensor (DPF) Mounting Bolts

M6 x 1.0
Torque Specification
6.5 ft-lbs (9 N·m)
Important Notes
Ensure sensor is properly aligned and use new o-rings if available. Over-tightening can damage the sensor.

Mass Airflow Sensor

1

Mass Airflow (MAF) Sensor Mounting Bolts

M5 x 0.8
Torque Specification
4.5 ft-lbs (6 N·m)
Important Notes
Ensure the sensor is properly seated and the mating surfaces are clean and free of debris. Do not overtighten.

Exhaust

Torque specifications for Exhaust

Exhaust Manifold

1

Exhaust Manifold/Header to Cylinder Head Bolts

M8 x 1.25
Torque Specification
23 ft-lbs (31 N·m)
Important Notes
Ensure mating surfaces are clean and free from debris. Apply even torque in a circular or crisscross pattern.

Exhaust Piping

1

Exhaust Pipe to Exhaust Manifold/Header Bolts

M8 x 1.25
Torque Specification
23 ft-lbs (31 N·m)
Important Notes
Ensure proper alignment of flanges before tightening. Use new gaskets if applicable.
2

Catalytic Converter to Exhaust Pipe Bolts

M8 x 1.25
Torque Specification
23 ft-lbs (31 N·m)
Important Notes
Verify proper alignment to prevent stress on the catalytic converter. Use new gaskets.

Muffler

1

Muffler to Exhaust Pipe Bolts

M8 x 1.25
Torque Specification
23 ft-lbs (31 N·m)
Important Notes
Ensure muffler is properly supported and aligned to prevent vibrations.

Exhaust Hangers

1

Exhaust Hanger/Bracket Bolts (M8)

M8 x 1.25
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Ensure the exhaust system is properly aligned before tightening all hanger bolts. Check for vibration after installation.
2

Exhaust Hanger/Bracket Bolts (M10)

M10 x 1.5
Torque Specification
33 ft-lbs (45 N·m)
Important Notes
Ensure the exhaust system is properly aligned before tightening all hanger bolts. Check for vibration after installation.

Sensors

1

Oxygen Sensor (18mm Thread)

M18 x 1.5
Torque Specification
30 ft-lbs (40 N·m)
Important Notes
Apply anti-seize compound to the threads. Do not over-tighten, as this can damage the sensor or threads.

V Band Clamps

1

Exhaust Flange V-Band Clamp Bolt

M8 x 1.25
Torque Specification
3.67 ft-lbs (5 N·m)
Important Notes
Tighten the V-band clamp bolt evenly to ensure a leak-free seal, without over-tightening.

Fuel

Torque specifications for Fuel

Fuel Rail

1

Fuel Rail Mounting Bolts

M8 x 1.25
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Ensure proper sealing and avoid over-tightening to prevent fuel leaks. Apply even torque across all bolts.
2

Fuel Injector Mounting Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Ensure proper injector sealing to prevent leaks. Use new seals if removed. Apply even torque.
3

Fuel Line Connection (Banjo) Bolts to Fuel Rail/Injectors

M10 x 1.0
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
Use new crush washers for proper sealing. Do not over-tighten to avoid damaging the banjo fittings. Confirm torque is correct based on line type and bolt size.
4

Fuel Pressure Sensor Mounting Bolt

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Ensure proper sensor seating and do not over-tighten to prevent damage to sensor body.

Fuel Pump

1

Fuel Pump Mounting Bolts

M8 x 1.25
Torque Specification
15 ft-lbs (20 N·m)
Important Notes
Ensure the fuel pump is securely mounted and avoid over-tightening which could damage the fuel pump bracket. Apply even torque to all mounting points.
2

Fuel Tank Strap Bolts

M10 x 1.5
Torque Specification
22 ft-lbs (30 N·m)
Important Notes
Ensure even pressure across all straps. Do not over-tighten, as this could distort the fuel tank.
3

Fuel Tank Sending Unit Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Ensure proper sealing of the sending unit to prevent fuel leaks or inaccurate readings. Apply even torque and do not over-tighten.
4

In-Tank Fuel Filter/Pump Retaining Ring

N/A
Torque Specification
18 ft-lbs (25 N·m)
Important Notes
This is a retaining ring, not a bolt, but requires specific torque to form a proper seal. Ensure proper alignment of the retaining ring with the tank opening before torquing. This value is an estimate, check specific service manual for exact torque

Fuel Delivery

1

Fuel Filler Neck Mounting Bolts

M8 x 1.25
Torque Specification
22 ft-lbs (30 N·m)
Important Notes
Ensure proper alignment of the filler neck and do not over-tighten which could damage the filler neck or mounting points.
2

Fuel Filter Mounting Bolt/Nut

M10 x 1.5
Torque Specification
22 ft-lbs (30 N·m)
Important Notes
Ensure the filter is properly seated to prevent leaks. Use new crush washers if it’s a banjo-style connection. Do not over-tighten, as this could damage the filter assembly or banjo fittings.

Electrical

1

Fuel Pump Electrical Connector Bolt

M4 x 0.7
Torque Specification
2 ft-lbs (3 N·m)
Important Notes
This bolt secures the electrical connector and must be tightened snugly, but not over-tightened to avoid damage. Torque value is an estimate based on similar bolt size, hand-tightening is also acceptable. Use care not to strip the threads on plastic components.

Hvac

Torque specifications for Hvac

Ac Compressor

1

A/C Compressor Mounting Bolts

M10 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Ensure compressor is properly aligned before tightening. Use new bolts if specified by the manufacturer.
2

A/C Line Fittings

N/A
Torque Specification
N/A
Important Notes
A/C line fittings are typically hand-tight plus a slight turn, approximately 1/4 turn past hand tight. Over-tightening will damage the sealing surfaces. Use two wrenches to secure the fitting, one for the line and one for the fitting itself.
3

A/C Pressure Sensor Mounting Bolt

M6 x 1.0
Torque Specification
N/A
Important Notes
Hand-tight plus a slight turn. The sealing surface of the sensor is very sensitive and easily damaged. Do not over-tighten.

Ac Condenser

1

A/C Condenser Mounting Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Bolts are typically M6 and low torque to avoid damaging the mounting brackets. This is an estimated value.
2

A/C Receiver Drier Mounting Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Bolts are typically M6 and low torque to avoid damaging the mounting brackets. This is an estimated value.

Hvac Blower

1

HVAC Blower Motor Mounting Bolts

M5 x 0.8
Torque Specification
5 ft-lbs (7 N·m)
Important Notes
Ensure the blower motor is properly seated before tightening. Bolts are typically small and low torque to avoid damaging the plastic housing. This is an estimated value.
2

HVAC Control Panel Mounting Screws

M4 x 0.7
Torque Specification
3 ft-lbs (4 N·m)
Important Notes
Screws are typically small and low torque to avoid damaging the plastic housing. This is an estimated value.

Hvac Evaporator Core

1

Evaporator Housing/Core Mounting Bolts

M6 x 1.0
Torque Specification
5 ft-lbs (7 N·m)
Important Notes
Bolts are typically M6 and low torque to avoid damaging the plastic housing. This is an estimated value.
2

Expansion Valve Mounting Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Bolts are typically M6 and low torque to avoid damaging the mounting surface or the valve itself. This is an estimated value.

Hvac Heater Core

1

Heater Core Mounting Bolts

M6 x 1.0
Torque Specification
7 ft-lbs (10 N·m)
Important Notes
Bolts are typically M6 and low torque to avoid damaging the plastic housing. This is an estimated value.

Hvac Actuators

1

HVAC Blend Door Actuator Mounting Screws

M4 x 0.7
Torque Specification
4 ft-lbs (5 N·m)
Important Notes
Screws are typically small and low torque to avoid damaging the plastic actuator housing. This is an estimated value.

Suspension

Torque specifications for Suspension

Front Suspension

1

Front Strut/Shock Absorber Mounting Bolts (to chassis/body)

M12 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Secures the strut/shock assembly to the vehicle's chassis. Tighten to the specified torque to ensure a secure connection.
2

Lower Strut/Shock Bolt (to wheel bearing housing/knuckle)

M14 x 1.5
Torque Specification
74 ft-lbs (100 N·m)
Important Notes
Connects the lower end of the strut/shock to the wheel bearing housing. Ensure the bolt is properly aligned before tightening.
3

Strut Top Mount Bolts (to chassis/body)

M8 x 1.25
Torque Specification
22 ft-lbs (30 N·m)
Important Notes
These smaller bolts secure the strut top mount to the vehicle's body. Tighten them evenly to ensure a proper connection.
4

Front Control Arm Bolts (Inner and Outer)

M14 x 1.5
Torque Specification
74 ft-lbs (100 N·m)
Important Notes
Secures the control arm to the chassis and wheel hub assembly. Tighten to the specified torque to ensure proper suspension movement. Includes both inner and outer mounting points.
5

Front Ball Joint Nut

M12 x 1.5
Torque Specification
48 ft-lbs (65 N·m)
Important Notes
Secures the ball joint to the control arm or steering knuckle. Ensure the nut is properly seated before tightening.
6

Front Tie Rod End Nut

M12 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Secures the tie rod end to the steering knuckle. Proper torque is essential for maintaining proper steering alignment.
7

Front Sway Bar Link Nut

M10 x 1.5
Torque Specification
37 ft-lbs (50 N·m)
Important Notes
Connects the sway bar to the suspension. Proper torque ensures the sway bar effectively reduces body roll.

Rear Suspension

1

Rear Upper Control Arm Bolt

M14 x 1.5
Torque Specification
74 ft-lbs (100 N·m)
Important Notes
Secures the upper control arm to the chassis and hub assembly. Tighten to the specified torque to ensure proper rear suspension operation.
2

Rear Lower Control Arm Bolt

M14 x 1.5
Torque Specification
74 ft-lbs (100 N·m)
Important Notes
Secures the lower control arm to the chassis and hub assembly. Tighten to the specified torque to ensure proper rear suspension operation.
3

Rear Toe Link Bolt

M12 x 1.5
Torque Specification
74 ft-lbs (100 N·m)
Important Notes
Controls the toe angle of the rear wheels. Proper torque is essential for maintaining proper alignment.

Sway Bar

1

Sway Bar Bushing Bracket Bolts (to chassis/body)

M8 x 1.25
Torque Specification
22 ft-lbs (30 N·m)
Important Notes
Secures the sway bar bushings and brackets to the chassis. Tighten evenly to ensure the sway bar is properly anchored.

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

What are the general torque specifications for the BMW i8 2014-2020?

Refer to the BMW i8 Service Manual for specific torque values. Tightening torques vary depending on the component and material being fastened. Consult the manual for detailed specifications.

Q2

What tools are recommended for accurate torque application on a BMW i8?

Use a calibrated torque wrench that meets or exceeds BMW specifications. Digital torque wrenches provide precise torque readings and ensure proper tightening.

Q3

How do I determine the correct torque sequence for the BMW i8 engine cylinder head bolts?

Always refer to the BMW i8 Technical Information System (TIS) for the specified tightening sequence and torque values. Improper torque sequence can cause engine damage.

Q4

Can I use threadlocker on bolts and screws during assembly?

Apply threadlocker only when specified in the BMW i8 Service Manual. Use the recommended threadlocker type and quantity to prevent over-tightening and ensure secure fastening.

Q5

What are the consequences of over-tightening or under-tightening bolts on the BMW i8?

Over-tightening can strip threads, damage components, or cause premature failure. Under-tightening can lead to loose connections, leaks, and potential safety hazards. Always follow the specified torque values to ensure proper assembly.

Q6

How often should I check the torque of critical fasteners on my BMW i8?

Regularly inspect and re-torque critical fasteners according to the BMW i8 maintenance schedule or as recommended by a qualified technician. This helps prevent loosening and potential issues.

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

Digital Torque Wrench (10-100 Nm)

Essential for tightening fasteners to precise torque specifications, preventing damage and ensuring proper assembly. This range IS suitable for many applications on the i8.

  • Digital display for accurate readings
  • Audible alarm when target torque IS reached
  • Multiple units (Nm, ft-lb, in-lb)
  • Reversible ratcheting mechanism
Learn more
Service Procedures

Suspension Component Torque Specifications

Technical procedure specific to BMW i8 suspension components

  • Tighten front lower control arm rear bolt to 65 Nm
  • Tighten front lower control arm front bolt to 75 Nm
  • Tighten rear upper control arm bolt to 100 Nm
  • Tighten rear lower control arm bolt to 80 Nm
View full procedure

Engine Mounting Torque Specifications

Technical procedure specific to BMW i8 engine mounting components

  • Tighten engine support mounting bolt (M10) to 45 Nm
  • Tighten engine support mounting bolt (M12) to 60 Nm
  • Tighten transmission mounting bolt (M10) to 45 Nm
  • Tighten transmission mounting bolt (M12) to 60 Nm
View full procedure
Technical Service Bulletins

Technical Service Bulletin: Suspension Bolt Torque Correction

2018-03-15

Updated torque specifications for certain suspension bolts on 2014-2018 i8 models

2014-2018 i8

Resolution: Refer to updated torque specifications in the revised procedure

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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.
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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.

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