BMW F20 F21 F22 F23 F30 F31 F34 F32 F33 F36 B48 B58 coolant expansion tank 17138677649

Genuine BMW coolant expansion tank (Part No 17138677649) for F-series cars with B48 or B58 engines - no guesswork, no compatibility charts. Fits exactly as OEM: same mounting points, hose routing and cap interface.

Replaces ageing factory plastic before cracks cause low-coolant warnings or leaks on fast-road or track-day use. Not a pattern part - it’s the real thing, built to BMW’s spec.

• Direct fit for F20, F21, F22, F23, F30, F31, F34, F32, F33 and F36 models
• Confirmed for B48 and B58 petrol engines only - not for N20, N55 or diesel variants
• Same durability as factory unit - suitable for daily driver or spirited use