BMW 3 Series (E46) - Problems

Problems

Like all car models, some common faults or premature failures have become apparent with the E46 over time. These include:

• Front lower suspension control arm bushes and/or balljoints wear out as early as 30,000 miles, causing knocking and sloppy handling. The whole arm normally has to be replaced but this is a quick workshop job.
• On Touring models, rear coil springs frequently break and the wiring to the rear tailgate components often suffers from breakage where it flexes between the body and tailgate.
• Steel brake pipes corrode and may need to be replaced at a relatively young age. The rear pipes pass over the fuel tank, making this a lengthy job.
• The more powerful six-cylinder cars (330d and 330i) can suffer from rear subframe cracking caused by torque reaction at the differential mounts.
• Pre-2004 diesel engines can suffer from swirl flap failure, which often writes off the vehicle due to extensive engine and turbocharger damage. The flaps can be removed by independent workshops with little effect on performance.
• All diesels can suffer from turbocharger failure. The early type of oil breather is implicated in this, as it blocks easily, restricting the oil feed to the turbo bearings. Post-2004 cars have a vortex-type breather which can easily be retrofitted to earlier cars. As with all oil-cooled turbochargers, it is important not to turn off the engine for a few minutes if the car has just been driven hard (with significant turbo boost).
• The final stage resistor on cars with climate control partially burns out, leading to a loss of proper heater fan control. The resistor, located in the footwell area, is replaceable although somewhat difficult to access.