N54 E90 E92 335i 135i Billet Water Hose Fitting 11537541992 11537544638

Replaces the brittle plastic thermostat housing outlet on N54 engines - the one that cracks, weeps, and dumps coolant mid-fast-road run or track-day session.

• Fitment is precise: E90/E92 335i, E82 135i, plus any N54 with OEM part numbers 11537541992 or 11537544638
• Not for N55/N20/N53: those use different O-ring geometry and port angles - this is N54-specific
• Machined from 6061-T6 billet aluminium, not cast junk; 25mm ID hose seat, M22x1.5 thread
• Search terms this actually matches: N54 decat coolant fitting, E92 stage 2 water outlet, 335i fast road thermostat adapter, N54 track day coolant upgrade, BMW E90 billet hose connector