About this part
What it does. Dayco POLY RIB BELT, DAYCO Dayco 311-5070685 drives engine accessories such as the alternator, water pump and air-conditioning compressor.
Symptoms that point to this part
- Squealing on cold start
- Visible cracking or glazing
- Accessories losing power
Fitment. Catalogued as fitting 2023–2026 BMW X7, 2025 BMW X5, 2024–2025 BMW X6, 2023–2024 BMW 760i Xdrive. Engine, sub-model and trim can narrow fitment further, so check those attributes on the listing before ordering.