When it comes to building a driver-focused car, there are few manufacturers with more success stories than BMW. It has produced a wide range of bangers over the years, with its creations combining everyday versatility with addictive driver engagement, setting them apart from their rivals. One of the most notorious and best-loved is the E46 M3, which combined a crisp six-cylinder engine with refreshing handling and a well-proportioned body.
They possess a huge fanbase, but there are plenty of fascinating tales about the model that you perhaps had overlooked while poring over the equally awesome performance stats.
The E46 M3 Is One Of The Most Popular Of The Breed
Years Produced
2001-2006
Total E46 M3 Production
85,766
The E46-generation BMW M3 unleashed in 2001 as the German looked to make an impact in the new millennium. The 3.2-liter S54 engine was developed specifically for the new car, and the team ensured it produced more grunt than its predecessor. A sleeker and more modern body than the previous M3 helped reduce drag. Having built upon the successful recipe of the first two generations of the M3, gearheads across the world were sold on the E46 from the moment it emerged.
The model went on to become the best-selling M3, with over 85,000 cars being sold across the globe. This puts the E46 around 13,000 units clear of its predecessor, despite being on sale for one less year. In fact, the E46 has yet to be eclipsed in sales by any of its successors, making it the most successful M3 model produced thus far.
The SMG Gearbox Was Fairly Popular
Total E46 M3 Production
85,766
SMG Production
40,125
Manual Production
45,651
Another addition offered on the E46 M3 was the second-generation BMW SMG transmission. SMG is essentially an automated manual gearbox, with a hydraulic system being present to shift the gears without the use of a clutch pedal found on a traditional manual. Having debuted on the E36 M3, the new SMG II found on the E46 was slicker and faster than the first iteration of the gearbox, and offered drivers the chance to focus purely on the driving.
Still, most E46 buyers preferred the more involving experience of a manual gearbox, so it edged out the SMG II in sales. It was close between the two though, with just over 45,500 manual cars sold, and a little over 40,000 SMGs. Automatic transmissions have become more dominant these days, but the E46 showed that the love for the manual was still strong back then.
The SMG Isn’t As Unreliable As It Sounds
Speaking of the SMG, the transmission developed a reputation for being relatively unreliable compared to the standard manual. In fact, this reputation is rather exaggerated for the most part.
The SMG II was based on the Getrag six-speed manual transmission used in the E46 M3, with the main difference being the addition of a hydraulic system to operate the clutch. Contrary to public opinion, the gearbox itself is pretty strong, and the only real problems regard the hydraulic system.
The pump and solenoids installed within the unit can fail over time, and are costly to replace. The issues aren’t as common as you may think, though, and driving smoothly and regularly servicing the gearbox will help keep the unit running reliably. Many SMG-equipped M3s have far eclipsed the 100,000-mile mark without major issue, so don’t simply assume the SMG II is an automatic death sentence to your wallet.
Early E46 M3’s Suffered From A Critical Engine Problem
Engine
3.2-liter Inline-6
Horsepower
343-360 hp
Torque
269 lb-ft
0-60 MPH
4.9 seconds
Top speed
155 mph (limited)
While the E46 M3 is generally a reliable machine, it has had its moments. One particularly scary issue reared its head in 2003, when BMW issued a service bulletin for all E46 M3s built between 2001 and 2003 for a potentially disastrous rod bearing issue. The bulletin, titled SI B 11 04 04, was issued because the original rod bearings in affected cars had a tendency to overheat and fail when run at high revs for extended periods, which subsequently led to severe engine damage.
BMW revealed that subpar quality control had led to parts not being manufactured correctly, meaning they didn’t perform as well under load as they should have. Every affected engine was fitted with redesigned rod bearings that wouldn’t overheat, and all subsequent cars also received the enhanced components. It was a worrying time for E46 M3 owners, and the program has been somewhat forgotten over the years.
The M3 Can Have A Dodgy Oil Pump
There is another, even rarer problem that can affect S54 M3 engines that E46 enthusiasts would rather not think about. The nut holding the drive sprocket for the engine’s oil pump can detach, which ultimately causes the pump to fail and leads to near-instant oil pressure loss. The result is oil starvation in the engine, which causes severe overheating and eventual catastrophic internal damage. The vibrations within the engine cause the nut to loosen in extreme circumstances, leading to its detachment.
The problem is extremely rare on E46 M3s, and usually only happens in ultra-high-intensity situations, such as sustained track driving. An upgraded nut is available that prevents the problem from occurring, and is usually a worthwhile enhancement if you frequently track your example.
There Are Performance-Enhancing Airboxes Available
Adding a carbon-fiber airbox, like that used on the awesome BMW M3 CSL, is one of the most popular mods available for the E46 M3, so there’s no secret here. Going further, there are several types of aftermarket airboxes available, and those not familiar with the upgrade process could find themselves slightly confused. Generally, the two main options on the market are those produced by Turner Motorsport and Karbonius.
The Karbonius component is closer to the OEM part, and its shape tends to produce a better noise than Turner’s offering, according to enthusiasts. Plus, the part’s fit and finish are superior. By contrast, the Turner component has a slightly different design that produces slightly more grunt at higher RPMs. This makes it better suited for those looking to extract the most power possible for a track build, and it’s cheaper to buy, too.
Be Careful When Tuning
Another lesser-known element of introducing a revised airbox to the E46 M3 is that you need to incorporate a new engine tune to make it work properly. The standard mass airflow sensor doesn’t work with the aftermarket CSL-style airbox arrangement, so you also have to retune the S54. Several upgrades are available. For example, the one from the company Alpha N essentially circumvents the lack of a MAF sensor by taking into account throttle position and RPM and using a new calculation to ensure the engine runs as smoothly as it should.
Once completed, the engine can make use of the sharper throttle response and extra power provided by the new airbox. Using a skilled tuner with the map is essential, though, as simply installing the Alpha N software without fine-tuning can cause an unsteady idle and mid-RPM range hesitation, which detracts from the driving experience rather than enhancing it.
Related
Here’s What Makes Every Generation Of BMW M3 Special
If you were to create a single M3 with the best traits from every generation that’s ever existed, what would it look like?
Look For The Competition Package
While the CSL is the most famous factory-upgraded version of the E46 M3, there is another, less well-known option. Called the Competition Package, or ZCP internally, the M3 was graced with a range of performance enhancements that helped provide a more responsive drive for those who paid extra. Larger brake rotors were up front, while the car’s steering ratio was also quicker. The changes included:
- Uprated discs front and rear, new material and larger size to improve braking performance
- Upgraded steering rack
- M Mode got less restrictive stability control
- New 19-inch wheel design
- Alcantara steering wheel
- Aluminum-trimmed cabin
- Exclusive Interlagos Blue metallic exterior paint option
The threshold of when the stability control activated during the M driving mode was also slightly raised, and a special set of 19-inch wheels was included. The cherry on the cake was a racier interior that included an upmarket, grippy Alcantara steering wheel.
The Package Transforms The Feel Of The Car
These changes weren’t simply aesthetic, either, as the M3 became much more of a precision-driving tool thanks to the ZCP Package. The uprated steering ratio helped quicken up the steering considerably, which assisted the agility of the car once you turned the wheel. It was also more alive on the brakes thanks to the componentry, while the more aggressive stability control setting ensured you could cut some more aggressive shapes with the vehicle before it tried to stop you.
For those looking for a more focused and hardcore factory M3 without spending the insane money needed for a CSL, the ZCP Package is well worth searching for.
Related
Everyone Is Wrong About Which BMW M3 Generation Is The Best
There is simply nothing better than the one (and only) V8 M3.
The Standard M3 Can Be Had With CSL Bits
The M3 CSL is known for being superior to the standard E46 M3 because it weighs considerably less and has an upgraded S54 engine that produces 360 horsepower, but there is more to the story than that. The upgraded braking system ensured it could not only stop faster and more aggressively than the standard car but also do so more consistently before overheating. Plus, the brake discs were larger at both ends.
The ZCP Package uses the same steering rack as the legendary CSL. This means that while it lacks the extra go-faster juice and weight-saving potential of the full-fat model, this is still a vehicle that boasts equally responsive steering. This lesser-known fact could at least make you feel better about not being able to enjoy a genuine CSL. Hopefully, for your bank account’s sake.
Sources: BMW.
