Expansion Tank Cap

Product Details

When you are pushing your BMW on the street or the track, your cooling system is under immense stress. A weak, worn-out expansion tank cap is a major liability that can quickly lead to an overheated engine and a ruined day. The factory caps are notorious for failing silently, dropping their holding pressure and causing your coolant to boil over at much lower temperatures than intended.

Maintain maximum cooling efficiency and system pressure with this Febi Bilstein 2.0 bar replacement cap. Febi is a trusted name in German replacement parts, delivering original equipment fitment and reliability without the dealership markup. Designed specifically for BMW's larger primary expansion tanks, this cap maintains a tight seal and vents safely only when pressure surpasses 2.0 bar. Keep your cooling system pressurized, your boiling point high, and your engine safe.

Key Features

• Guarantees proper cooling system pressure for optimal boiling point protection.

• An absolute must-have replacement during any radiator, hose, or expansion tank overhaul.

• OEM-equivalent fitment and function at a fraction of the dealer price.

• Premium rubber sealing ring ensures a leak-free interface with the expansion tank neck.

• Engineered to resist the corrosive properties of modern BMW coolant additives.

Specifications

• Manufacturer: Febi Bilstein

• Part Number: 46222

• Replaces BMW OE Number: 17117639021 (and older 17137516004)

• Opening/Relief Pressure: 2.0 bar (29 psi)

• Material: Heavy-duty plastic

• Thread Size: M52 x 3

• Color: Black

• Weight: 0.063 kg

Prop 65 Warning

Product Q&A

Lifetime Replacement

Fits These Cars