Common issues & diagnosis
Overflow bottles in older vehicles can need replacing. Long exposure to high temperatures and pressure will eventually cause the plastic to degrade and break.
What is the part's function?
Expansion tanks are primarily designed to act as an overflow reservoir for the coolant, which expands as it heats up. They also provide a place for air bubbles within the coolant system to go.
How to determine fitment compatibility
There can be a few different types of expansion tank for each model generation.
The best way to determine fitment compatibility of a expansion tank is to match the BMW part numbers from the catalogue. This can be done by decoding your vehicle’s VIN in a BMW EPC (electronic part catalogue.)
If you don’t have access to an EPC, provide our team with your vehicle’s 17-digit VIN—and we’ll check our stock for a compatible match.
Interchangeability between models
There is low-interchangeability of overflow bottles between models.
