2003 BMW 325I low fuel stall

- La Mesa, CA, USA

The BMW E46 3-series (1999-2006) suffers from a design flaw in the cooling system. Plastic parts in the cooling system fail as soon as 4 years and 80,000 miles from manufacture date, often failing catastrophically and causing the engine to overheat. Continued driving of the car in this situation leads to complete engine failure and loss of power (including power steering and power brakes), potentially causing an accident if it happens at highway speeds. Typical failed parts include the coolant expansion tank, radiator end tanks, and water pump impellers or bearings. (BMW came up with an improved water pump design around 2004 that is more reliable.) cars with automatic transmissions also suffer failures of the mechanical fan clutch and the transmission cooling thermostat. Failure of the fan clutch (found only on automatic transmission cars) can cause the fan blades to break off and damage the radiator, serpentine belt, and water pump, as well as the car's hood. At higher mileages (>150,000 miles) the plastic coolant pipes often fail, causing overheating and requiring major work to replace. On my car the coolant expansion tank and radiator both failed and were replaced. The thermostat also stuck open resulting in lower gas mileage until it was replaced. Now one of my plastic coolant pipes is leaking. BMW should be required to repair failed plastic cooling system parts on the E46 3-series with higher-quality parts designed to last at least 10 years and 100,000 miles from manufacture date.

- Los Gatos, CA, USA