Rein CHE0457 (11537545890 equivalent) hose between cylinder head and thermostat.
Hose for N52 (silver top) engines in E87 1 series, E9x 3 series, E85/E86 Z4 or N52K (black top) engines in E9x 3 series, E84 X1 only.
Location: Between cylinder head and thermostat.
Also known as 'Mickey Mouse' hose, notorious for breaking during oil filter housing repairs or suddenly while driving.