1984 BMW 318i 1.2 Bar; Screw On Cap;. Part Type: Engine Coolant Reservoir Cap. 1985 BMW 318i 1.2 Bar; Screw On Cap;. Compatible Years: 1984 1985. Notes: 1.2 Bar; Screw On Cap;. Expansion Tank Cap. Ensure that this part fits your vehicle by entering your vehicle's Year, Make, Model, Trim, and Engine in the Compatibility Table.