Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2018 Bmw 640iSerpentine Belt Diagram & Size
OEM serpentine belt spec from the factory service manual for the 2018-2019 (2018-2019).
Quick Answer
This vehicle's factory manual
2018 Bmw 640i: confirm the engine, trim, or drivetrain to open the available repair and diagnosis sections.
What You'll Need
These links search Amazon; confirm the belt or pulley against your engine, equipment and VIN before ordering. As an Amazon Associate, we earn from qualifying purchases.
Serpentine Belt
Bmw 640i Replacement Belt
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Tool
Belt Tensioner Tool
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Related Part
Idler / Tensioner Pulley
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For belt noise, inspect the belt drive and follow the vehicle's service procedure. Belt manufacturer Dayco advises against using belt dressing to solve serpentine-belt problems. Read Dayco's belt-service guidance.
Related for Your 2018 Bmw 640i
Frequently Asked Questions
- What size serpentine belt does a 2018 Bmw 640i use?
- Refer to the factory service manual for the exact serpentine belt specification for your 2018 Bmw 640i.
- How do I know if my Bmw 640i serpentine belt is bad?
- Common signs include squealing on startup (especially when cold), visible cracks or fraying on the ribbed side, power steering or A/C failure, and battery warning lights. The factory manual includes inspection criteria and replacement intervals.