Rein CHE0479 or Febi Bilstein 103042 (17127565094 equivalent) coolant crossover hose.
Rein CHE0479 or Febi Bilstein 103042 (17127565094 equivalent) crossover coolant hose for E8x 1 series and E9x 3 series models with N54 engine. Also fits E84 X1 with N20 4 cyl turbo petrol engine.
Runs from expansion tank to top radiator hose.
Replacement every 4-5 years is recommended to avoid breakdown requiring tow. Top radiator hose replacement recommended in conjunction as the barbed fitting for this hose is known to rot internally, breaking upon removal of old hose. If the top radiator hose plastic fittings are maroon/brown, failure is imminent.
Note: Depending on availability, we offer Rein and Febi Bilstein brands for this part. We believe they're as good as each other. Pictured is the Rein version.