✅ Fixed
BMW E46 cooling system: multiple plastic components fail at 80-120k miles. Replace proactively: 1) Thermostat housing (plastic cracks) — replace with aluminum aftermarket. 2) Expansion tank and cap — cracks suddenly. 3) Lower hose has internal wire mesh t
BMW E46 cooling system: multiple plastic components fail at 80-120k miles. Replace proactively: 1) Thermostat housing (plastic cracks) — replace with aluminum aftermarket. 2) Expansion tank and cap — cracks suddenly. 3) Lower hose has internal wire mesh that collapses — replace with radiator hose. 4) Water pump (plastic impeller fails) — replace with metal impeller version. 5) All together as preventive package: $300-600 in parts. Do all at once — labor overlap saves money. A failed expansion tank on highway causes immediate overheating.