The BMW 330i has been manufactured during two different generations. The first 330 was the E46 generation, while the current 330i is part of the E90 and E92 (coupe) generation of cars. Both models are powered by a 3.0-liter straight-six engine that offers strong performance. Like any car, there are some areas buyers and owners should be aware of when it comes maintenance and potential problems.
The E46 330i was powered by an all new 2,797cc inline-6 called the M54. This engine produced 225-hp and powered the 330i sedan, 330Ci coupe and convertible, and the all-wheel-drive 330xi. The motor in these cars is by and large durable and reliable with the proper maintenance. There have been reports of the engine ECUs (electronic control units) needing to be rebuilt by BMW to cure rough idles, flat spotting or problems with power delivery. This seems to have been limited to cars with manual gearboxes and in particular cars with the optional (and rare) high-performance ZHP package.
The engines in the latest 258-hp version of the 330, launched in 2006, have like their predecessors, proven reliable so far. However, some owners have reported automatic gearboxes that are hesitant to shift or do not shift smoothly.
The E46 330 came with water pumps that should to be replaced every 60,000 or so miles. Likewise, it is recommended that the radiator be replaced at 90,000 miles as preventative maintenance.
Early E46 ball joints are a weakness and can be replaced with the later and stronger ball joints. On occasion, rear coil springs have been known to break, requiring the replacement of both. There have also been very rare rear floor failures, where the rear suspension mount literally rips out of the floor. Some early E46s had driveline vibrations that required the driveshaft, transfer case or rear differential be replaced.
Some owners have complained of heavy steering in some model year 2000 cars. BMW has retrofitted some of these cars with later steering racks to add more power boost and make them easier to drive at parking lot speeds. Owners of model year 2000 cars have also reported vibrating steering, which has been traced to defective front control arms and rotors.
The E46 interiors as a general rule hold up well, with only minor issues such as failed radio displays. The sunroofs can be a problem area on early E46s. To prevent problems, it is recommended that you grease the sunroof tracks regularly. The switch for the sunroof has also been known to "lose" or forget the initialization for its various positions. Resetting it involves noting the position of the sunroof and then holding the switch in that position for 20 seconds.
Some owners of the E90/92 330 have reported that the rubber used to give the interior surfaces the luxurious, "soft touch" feel has been getting soft and sticky and coming off in some cases.
Both the E46 and E90 generation 330s are very well-built, reliable cars when properly cared for. Like any high-end German vehicle, proper maintenance is crucial and any used purchase should include a pre-purchase inspection.
