BMW 3 Series E46 4th Generation 1999-2006 Review

Arriving for the 1999 model year in sedan form and joined a year later by its coupe, convertible, and wagon siblings, the fourth-generation BMW 3 Series (E46) retained its predecessor's virtues, but added more cabin space, luxury, and high-end features to the recipe.

The E46 3 Series remained cosmetically unchanged for its first two years, before a comprehensive overhaul for the 2002 model year updated the sedan and wagon's appearance and added more features. The coupe and convertible's comparable facelift arrived in 2003, following which the latter two models remained in production until 2006.

Every element of the facelifted E46 BMW 3 Series's front received an update. There is a new hood and fenders, a new grille and headlights, and a redesigned bumper to underscore the other revisions.

Perhaps the most noticeable difference between the pre- and post-facelift models is in their headlight designs. The older model's lights have straight lower edges with small semi-circular cutouts which follow the contours of the reflectors within, while the facelift changed this to two overlapping ovoid shapes without any straight lines to be seen. The upper headlight edges are also more acutely curved following the facelift¹, and the double-kidney grille is significantly wider².

The hood³, fenders⁴, and filler panels below the headlights are also changed⁵ to follow the new headlight and grille shapes, but in the process, much of the pre-facelift model's taut, compact appearance got lost. The redesign of the bumper compensates for the fussier treatment up top, though, with a taller single air intake⁶ and round foglights, instead of the pre-facelift car's shallow, multi-segment air intake and rectangular foglights⁷.

Changes to the facelifted E46's rear end are more subtle than those applied to those in front, but do a great job of modernizing the car's backside. While the sheet metal remains unchanged, the tail lights and bumpers are more in tune with the design trends of its era, with crystal taillight clusters in a three-strip arrangement and a less fussy bumper design.

The indicators are relocated to the center strip, and wrap around the backup lights on the trunk-lid-mounted sections, instead of the older model's top-mounted indicator lamps and separate insert for the backup lights¹. The bumper is reprofiled with fewer creases, and loses the lower black trim insert which always looked slightly out of place on the pre-facelift car².

Seen in profile, the facelifted BMW E46 has more pronounced bulges in its lower side skirts for a sportier appearance¹, and the side indicator repeaters are relocated to the styling crease running through the body side, instead of the pre-facelift model's free-standing units mounted near the side protection strip².

The new light clusters are noticeable from the side, and the simplified bumper designs are also very apparent3. There are new front fenders as well, to accommodate the new headlight clusters, and the creases in the front fenders end behind the front wheel arches, instead of over the wheel centers, as on the pre-facelift model⁴.

Unlike its exterior, the facelifted E46 BMW 3 Series doesn't look much different from the facelifted model. The most obvious difference is the steering wheel, which changes from a four-spoke to a three-spoke design across all variants, and receives a smaller airbag cover on trims that were already equipped with a three-spoke wheel¹. On examples fitted with navigation, the display screen is larger than on the pre-facelift cars².

BMW dropped the "ti" three-door hatchback as well as all four-cylinder engines from the BMW E46 3 Series line-up, although the old-generation E36 three-door, coupe, convertible, and wagon continued for the 1999 model year.

The diesel options offered in other world markets also didn't make it to North America, leaving the US range with only two gas powerplants from which to choose. The initial range consisted of the 323i, which carried over the 2.5-liter M52TUB25 engine from its predecessor, and the 328i, which used the equally-familiar M52TUB28. Both engines offered a choice between a five-speed manual transmission and a five-speed automatic.

At launch, power was sent only to the rear wheels, but this changed in 2001, when AWD became available in both sedan and Sport Wagon body styles and with either transmission, along with new names: 325xi and 330xi. However, the E46 convertible and coupe remained exclusively RWD.

The M54B25 engine also replaced the similar-sized unit in the 323i in 2001, giving it the 325i badge in the process, while the B54B30 engine found its way into the 328i replacement, now named the 330i. The 330i models, regardless of drive wheels or body type, exchanged the five-speed manual gearbox for a new six-speed unit during the 2003 model year, and a six-speed automatic transmission arrived for both 325i and 330i models in 2004.

The EPA encourages owners to submit their recorded real-world fuel-economy figures to their website, where these owners' figures could be compared to the official numbers. Unfortunately, not all 4th gen BMW 3 Series variants have available real-world information, but the majority of those that do, show that most owners manage to improve the combined EPA figures by an impressive 10% or more.

* Real-world mpg and MPGe figures are provided by the EPA. Once a car has been on sale for a significant period of time, the EPA gets real-world figures directly from the customer base. These figures are then provided on the EPA website. Real-world figures are not available for certain models due to a lack of sales, or not enough people partaking in this after-sales survey.

The E46 BMW 3 Series was very well-equipped with standard safety features for its era, and its basic safety specifications would still pass muster to this day. It featured an unusual airbag arrangement, with two frontal airbags, two side airbags, and two tube airbags to provide head protection for the front seats, and could be further upgraded to eight airbags with optional rear side airbags. For 1999, this was revolutionary technology, and predates today's curtain airbags by a good few years.

Also standard were seatbelt pretensioners in front, power-assisted four-wheel ventilated disc brakes with ABS and electronic brake-force distribution, traction control, halogen headlights with a xenon upgrade option, five height-adjustable head restraints, and child-seat anchors. For 2000, the traction control was upgraded to full stability control, and bi-xenon headlights became available with the 2002 facelift. The Premium package also added automatic high-beam control, but rear parking sensors remained optional on all trims throughout the E46's production run.

When the NHTSA tested the E46 BMW 3 Series sedan in 2005, they gave it a four-star rating for driver protection in a frontal collision, five stars for front passenger protection in the same test, and four stars for rollover protection. However, the side-barrier test earned only three stars for front occupant protection but five stars for rear occupants.

Bear in mind that this pre-2011 test cannot be directly compared to a test performed from 2011 onwards, because its requirements are not as stringent as the later test protocol. Note that the side-barrier test results will not apply to the convertible body style, due to its lack of a solid roof and B-pillar, but it does have a pop-up rollover protection system behind the rear seats.

BMW E46 trim designations are determined by the engine in use, with the larger-engined derivatives offering more standard equipment than the base-engined variants.The "x" in a post-facelift model's name simply indicates AWD, but its standard-features list is identical to that of the non-AWD version. This applies to the other body styles, too, although there may be some coupe- or convertible-specific features to be found in those models.

Opening the door and getting into the driver's seat of an E46 BMW 3 Series, the design's similarities to the E39 5 Series are immediately apparent. The ergonomics are well-resolved, the seating position is spacious and comfortable, and the general assembly and material quality is very high. The view to the front and sides is very good, although outward vision to the rear three quarters is limited due to pronounced roof pillars and a tapering glasshouse.

BMW also addressed the E36 3 Series' largest point of criticism, by enlarging the cabin space both front and rear. Front headroom of 38.4 inches and front shoulder room of 54.4 inches are larger than what the contemporary B5 Audi A4 could offer, and the front legroom of 41.4 inches is actually slightly more than even the B6 Audi A4 has for its front occupants.

Those in the rear of an E46 sedan will also be happier than they would have been in an E36, but it's still nowhere close to limo-like. It also beats the B6 Audi A4 on rear-seat space, which may sound like damning it with faint praise, but the bottom line is that four average-sized adult occupants won't have much cause for complaint in the BMW E46.

A maximum cargo capacity of 10.7 cu.ft. isn't anything special, though, and falls almost 3 cu.ft. short of what you'd get in the B6 Audi A4. If practicality is a priority, a BMW E46 Touring/Sport Wagon will be much better suited to your needs, with its enlarged cargo hold and standard folding rear seats. Avoid the BMW 3 series E46 coupe or convertible if you're serious about carrying people, though, because these two body styles major on style instead of practicality.

As far as maintenance and servicing go, the 4th generation 3 Series is no more or less troublesome than any other six-cylinder BMW from this era. And, because their engines are all so closely related, there is a very large measure of part interchangeability.

The key to a long and happy service life with an E46 BMW is religious maintenance according to the manufacturer's prescriptions. BMW reckons that the engine oil and its filter need to be changed every 5,000 miles, and we agree - these engines need a steady supply of high-quality synthetic oil to stay healthy.

Other service items have varying replacement intervals, with the engine air filter supposed to last for 60,000 miles and the cabin air filter needing replacement every 15,000 miles, but we'd recommend halving these intervals if the car is operated in dusty conditions. Spark plugs are said to be good for 50,000 miles, which is a sensible interval - provided no misfires develop before the plugs are due for replacement.

Transmission fluid in the manual gearboxes are sealed for life, and usually won't need replacement unless a leak develops somewhere. The automatic transmission fluid and its filter need to be replaced every 60,000 miles, however, to avoid BMW E46 automatic gearbox problems in the longer term.

We'd recommend flushing the power steering fluid at 60,000 miles as well, and brake fluid needs to be replaced every two years regardless of the mileage covered. And, every 15,000 miles or so, check the condition of the serpentine drive belt in front of the engine, and inspect it for hairline cracks. Fortunately, the M52 and M54 engine both use timing chains to drive their camshafts, and there are no special maintenance requirements for these items.

The BMW M52 and M54 engines both have an oil capacity of 6.9 quarts of 5W-40 full-synthetic oil (including a filter replacement), which could cost between $96 and $135, depending on the brand of oil and whether you prefer an OEM oil filter or not. Having a private workshop perform this service would cost around $140, including labor, so it may not be worth the hassle of doing it yourself.

All mainstream E46 6-cylinder engines use the same spark plugs and filters. A set of six spark plugs should cost between $38 and $98 from an aftermarket supplier or the dealership, respectively, and a private workshop will charge about $350 to supply the plugs and replace them for you.

Engine air filters cost between $12 and $23, and cabin air filters will set you back between $21 and $40, and they're both easy enough to replace yourself. However, if you get a private workshop to replace both these filters, expect to pay about $210, parts inclusive.

There were a number of 1999-2006 BMW 3 Series recalls, many of which are related to the airbags.

• All 1999-2006 E46 BMW 3 Series models and body styles were recalled for their driver and passenger frontal airbag inflators, which may either burst upon deployment, sending metal shards into the interior, or not inflate properly, which could increase the risk of occupant injury in a collision. There are many notices regarding the BMW E46 airbag recall, but they all point to the same two airbags. This is related to the ongoing Takata airbag saga, so please ensure that this recall has been executed according to the manufacturer's requirements.
• 2002-2005 BMW E46 3 Series sedans were recalled for taillight malfunctions, where excess resistance in the connections to the light clusters could result in the taillights not working as intended.
• 2002 model year BMW 325xi models were recalled for a manufacturing defect in the rear brake rotors, which could cause the brake discs to separate from the hub. The repair involves a BMW dealership replacing both rear brake rotors, obviously at no charge to the customer.
• Another problem affecting only 2002 BMW 3 Series cars involves the front top strut mounts, which may separate when the suspension is at full extension.
• On 2003 model year BMW E46 models, the power window anti-pinching device could malfunction.
• 2003-model BMW 325i vehicles with automatic transmissions had a recall for their idle-speed control system, which could elevate the idle speed in gear sufficiently to make the car feel like it's being pushed against the brake. This could be a serious problem, but the remedy is as simple as the dealership reprogramming the engine control unit.
• All 1999-2001 BMW E46 models have been recalled for a problem in the HVAC's blower-fan assembly, which could overheat and potentially cause an engine bay fire.
• There is another potential fire hazard in 1999-2001 BMW E46 vehicles, this time related to aftermarket replacement engine cooling fans made by Valeo, which may overheat and possibly catch fire.
• 2001-2005 BMW E46 vehicles with Cardone aftermarket replacement brake master cylinders have been recalled for internal leaks, which will affect braking performance. If your E46 has had a replacement brake master cylinder fitted, please check if your car is affected by this recall.
• Some aftermarket headlight clusters, manufactured by DOPE Inc and E Speed Racing, respectively, were recalled for not conforming to federal regulations. They don't have the required side-marker reflectors, increasing the risk of a side collision in low-light conditions. This affects all 1999-2006 BMW 3 Series models with these DOPE replacement headlights, and all pre-facelift E46 models with the E Speed headlights.

When scanning the onboard diagnostic of a BMW E46 3 Series vehicle, the following error codes may appear:

• P0030 indicates a problem with the oxygen sensor's heater circuit. P0171 and P1092 both mean that the engine is running too lean, and could appear due to vacuum leaks in the intake system.
• If the engine cannot reach optimal operating temperature after a predetermined time, it will trigger P0128.
• P030x codes indicate misfires, with the last digit changing to either show general misfiring (P0300), or to indicate which cylinder is misfiring, e.g. P0303 indicates a misfire on cylinder number three. P0313 indicates a lean-condition misfire, most likely due to insufficient fuel in the tank.
• If there's a problem with the crank-angle sensor or its wiring, the P0335 code will be triggered, while a similar problem with a crankshaft position sensor will trigger P0340.
• P0599 means that there's a problem with the thermostat heater control or its circuit.
• Problems with the automatic transmission are indicated by the generic P0700 code, which simply means that there's a malfunction in the transmission, and P0741 indicates that there's excessive slippage in the torque converter.
• P1315 indicates that ignition coil number four or its wiring harness is defective.
• If the engine control unit detects a misfire, it will cut the fuel supply to that cylinder to prevent catalyst damage and present a P1353 error code.
• If there is a problem with the throttle position sensor or its wiring, P1637 will be triggered.

Some owners have reported BMW E46 throttle body problems, which could be a major issue, considering that later models employed an electronically actuated throttle body to control everything from idle speed to engine response. These issues are usually resolved by cleaning the throttle body of any accumulated gunk, especially on cars with a prior history of PCV problems, but can also be caused by a poor electrical connection between the throttle body and its wiring harness, and could trigger a P0121 and P0123 error codes in the diagnostic system.

The starting system also appears to be largely trouble-free, with the only BMW E46 starter problems to report revolving around the standard-fit anti-theft system. Either the immobilizer control unit or the coded key could go wrong. In the former case, the only solution is to replace the faulty controller, but in the latter case, there's also a possibility that the ignition key simply needs to be reprogrammed. Some owners also report that the crash sensor, located in the main power line next to the battery in the trunk, could malfunction, which will also cause a no-start condition.

Closely linked to the probable immobilizer issue are problems with the BMW E46's central locking, boot lock, and key, which could point to the same control module. However, there is also a well-known problem with the GM5 module behind the glove box, which controls the locking system. This problem can often be repaired by replacing the some relays inside this module, following which it should be working again.

There are also very few complaints about the charging system, with BMW E46 alternator problems usually only occurring due to corrosion in the alternator, or plain old wear and tear on the internal carbon brushes or regulator. BMW E46 battery problems don't appear to be a notable issue, although some electronic components could cause a slow battery drain due to poor earth connections.

The climate control system appears to be quite robust, and BMW E46 AC and heater problems are usually solved by replacing the cabin air filter or ensuring that the airflow control flaps in the HVAC system are working properly. There don't seem to be any design flaws in the cooling hardware, however, so the AC compressor and heat exchangers shouldn't pose any issues.

Problems with the BMW E46's manual gearbox and clutch are few and very far between, and, because these cars didn't employ a limited-slip differential, they generally don't need any attention, apart from an occasional clutch replacement or perhaps repairing a leaking oil seal.

The brakes are another story, with many owners complaining about BMW E46 handbrake problems. However, it usually turns out that the handbrake was never properly adjusted on those problem cars, with very few cases of owners needing to replace any components to get it to work as it should and the rest eventually getting it right after repeated adjustments.

Very few owners mentioned BMW E46 water leak problems, apart from the engine's cooling-system leaks, that is. Body-related water leaks are usually caused by blocked drainage channels in the sunroof assembly or the roof pillars, and cleaning them out is often a massive mission. However, an unchecked leak could eventually lead to electric problems, as some control modules are located in quite vulnerable areas.

BMW E46 sunroof problems have been mentioned by a number of owners, and the problems usually revolve around the sunroof frame's assembly. Either the drive cable stops working or the tilt-sliding mechanism warps, and both of these faults will cause the sunroof to stop working. The worst bit is that it's a big and costly mission to repair, because half of the interior has to be torn-down to gain access. Consequently, many owners simply stop using the sunroof.

There are no body-specific 2000-2005 BMW E46 wagon problems, but convertible owners often have bad luck. BMW E46 convertible problems can range from wiring issues to position switches in the mechanism, and often include some issue or pressure drop with the hydraulic system that operates the roof.

Most of the E46 BMW 3 Series models are very good cars, but we'd rather look past a 1999-2000 model, for the simple reason that early examples used an older engine family and lacked some comfort and convenient features that appeared on later cars. As such, the 1999 or 2000 BMW 323i with an automatic transmission is probably the least desirable of the range, so that's the one we'd avoid.

This is where things get interesting, because not everyone loves the facelifted E46's appearance. However, there was one model year where the M54 engine was used in the pre-facelift body, which will make a 2001-vintage 325i or 330i the most appealing of the older examples.

But, if you don't mind its looks, a 2004 or 2005 330i can give you a six-speed manual transmission, and if it's equipped with the Performance Package (ZCP), you'll get a bunch of cosmetic enhancements and a sharper driving experience as well. That would be the driving enthusiast's choice in the range, and it also looks set to appreciate in value soon.

BMW set out to raise the standards of its class with the E46 3 Series, and succeeded in this brief. In fact, the E46 was still class-competitive in the face of newer opponents when it went out of production, and its following among BMW owners has only grown since then.

While there are a number of potential trouble spots with an E46, a well-maintained example will give a truly sporty driving experience and faithful service in the long run. Just remember to keep your hand on it, and repair anything that goes wrong right away, before it grows into a major issue. And, if you're not the DIY type, it's probably a good idea to build a strong relationship with your nearest private BMW specialist, because you may end up spending a lot of time in their company.