Overflow Bottle | 17137542986

The overflow bottle / coolant reservoir is the plastic reservoir mounted in the engine bay that stores the coolant for the engine. Overflow bottles are required because engines go through cycles of expelling and absorbing coolant as they warm up and cool down. When the engine is cold, the pressure of the cooling system is low and more coolant is required, and when the engine is warm the pressure of the cooling system is increased and therefore less coolant is required.

For some vehicles, the overflow bottle is an integral part of the system, and since it is also pressurised, the overflow bottle becomes an even more important component to engine safety. Because the overflow bottle is part of the cooling system, when it has any issues it can quickly lead to issues with the engine.

Replace your failed or failing part with this direct replacement.

Part also fits*

5 SERIES 2003 – 2010 E60/E61, 6CYL/V8, PETROL, 10/03-04/10
6 SERIES 2004 – 2011 E63/E64, COUPE/CABRIO, V8, PETROL, 05/04-04/11

*This is a guide only. If you are unsure if this part is suitable for your vehicle, please contact us and we can confirm prior to your purchase.