BMW 3 Series F30/31 2012-2019 (6th Gen) Review

Everything You Need To Know Before Buying A Used BMW 3 Series 6th Gen

Read in this article:

6th Gen BMW 3 Series: What Owners Say

  • There's much to like about the BMW 3 Series F31, with owners praising its solid construction and upmarket materials.
  • It handles well too, and both post-facelift gasoline-engine options are widely regarded as among the best in the industry. They pull strong from down low and provide great overtaking ability, and the ZF eight-speed automatic is tuned better than almost any competing auto 'box.
  • Outstanding performance doesn't come at the expense of frugal fuel economy, as the 3 Series still returns excellent gas mileage estimates from both official and real-world numbers..
  • As is typical of German products, the 3 Series doesn't exactly ooze value at the base level, and the expense of adding options quickly adds up when new. This does, however, mean that buying used could net you a great bargain.
  • Most complaints center around the iDrive infotainment system, which is accused of needing too much attention to be easy to use on the fly.
  • Other issues include a rough stop-start system. There have been a few complaints of mechanical problems relating to the turbos, timing chains, and other engine components relatively early in the vehicle's life, particularly on BMW 3 Series F30 (pre-facelift) derivatives.

Sixth Generation BMW 3 Series Facelift

2013-2018 3 Series F30 6th Gen Facelift Front Changes

The Bavarian brand gave the 6th-gen BMW 3 Series a substantial update for the 2016 model year. On the outside, a redesigned front fascia includes wider kidney grilles 1 and redesigned headlights 2, making full-LED clusters available for the first time. The bumper is an all-new design with the "V" theme extending all the way down to the bottom in the M Sport-equipped trims, bisecting the lower air dam. The lower air dam on the base trim is bigger and doesn't narrow as much in the middle 3. The Wagon received the same treatment front and rear.

2013-2018 3 Series F30 6th Gen Facelift Rear Changes

LED taillights can be found at the back 1, as can minor changes to the bumper design 2. The backup lights move from the top to the bottom of the trunk-lid-mounted clusters. New additions to the color palette include Mediterranean Blue Metallic, Platinum Silver Metallic, and Jatoba Brown Metallic.

2013-2018 3 Series F30 6th Gen Facelift Rear Changes

The profile is hardly changed at all and the only changes that can be spotted are some new wheel designs 1 and the changes to the front bumper 2 and lights 3.

2013-2018 3 Series F30 6th Gen Facelift Interior Changes

The last of the key changes center around standard specification, with the contents of the Sport Line specification included as standard. Leather availability was broadened, and the Premium Package is enhanced with Comfort Access, lumbar support, a power moonroof, and Sirius Satellite radio - all standard on the 340i.

Engine, Transmission and Drivetrain

The 6th-generation BMW 3 Series is available with several engine options. Not all the engines were available throughout the 3's lifecycle, as some engines were dropped, and others were added. The Wagon is only available with two engines. Pre-facelift models are equipped with either the turbocharged four-cylinder gas or diesel engine. The 328d remained throughout the Wagon's lifecycle, but the initial 328i was replaced with the more powerful 330i like the rest of the range. Most of the changes happened in 2016 when the 3 Series received a significant facelift. Beneath the skin, the changes are more substantial. The upgraded suspension includes new front struts, rear dampers, and a redeveloped electric power steering system. There's also an all-new family of engines, the B48 and B58 replacing the N20 and N55 engines, respectively. With this, BMW rechristened the 335i the 340i. The ZF eight-speed gearbox received revised tuning, while the six-speed manual on the 340i gets a dual-mass flywheel for smoother gear changes.

The available engine options for the 3 Series are as follows:

N20 2.0-liter Turbocharged Inline-Four Gas Engine
180/240 hp | 200/255 lb-ft
Horsepower
180/240 hp
Torque
200/255 lb-ft
Transmission
Six-speed manual or eight-speed automatic
Drivetrain
RWD or AWD (xDrive)

The 328i was the initial base offering in 2012. It's mechanically identical to the 2013 320i and comes in the same available configurations but its N20 engine is tuned to provide 240 hp and 255 lb-ft of torque. The AWD (xDrive) system provides additional grip in adverse conditions but doesn't add anything to the driving experience. The 320i was introduced later than the launch models (2013) and became the base model of the range. It has the same N20 2.0-liter turbocharged engine as the 328i but is tuned to produce 180 hp and 200 lb-ft of torque. Both a six-speed manual and eight-speed automatic transmission are available. The xDrive, or AWD model, adds additional grip for cold-weather states and is only available with the automatic transmission on the 328i. The N20 engine was replaced by the B48 for the 2017 model year, but only in the 328i, which then became the 330i; the 320i soldiered on with the less reliable N20 for the rest of the F30's production run.

N47 2.0-liter Turbocharged Inline-Four Diesel Engine |
180 hp | 280 lb-ft
Horsepower
180 hp
Torque
280 lb-ft
Transmission
Eight-speed automatic
Drivetrain
RWD or AWD (xDrive)

The last diesel 3 Series was introduced before the world found out about Dieselgate. It's an impressive engine with loads of torque, but not worth looking at. BMW has since stopped developing diesel engines, and this powertrain was not that reliable to begin with. We'd avoid this model purely based on limited parts availability.

N55 3.0-liter Turbocharged Inline-Six Gas Engine
300 hp | 300 lb-ft
Horsepower
300 hp
Torque
300 lb-ft
Transmission
Six-speed manual or eight-speed automatic
Drivetrain
RWD or AWD (xDrive)

Before the facelift, the 335i topped the lineup with a six-cylinder N55 engine displacing 3.0 liters and producing 300 hp and 300 lb-ft of torque. The AWD system provides additional grip, but only for cold-weather states. BMW's basic xDrive AWD system is not tuned for fun like it is on some M3 models, and you can't deactivate the front axle.

B58 3.0-liter Turbocharged Inline-Six Gas Engine
320 hp | 330 lb-ft
Horsepower
320 hp
Torque
330 lb-ft
Transmission
Six-speed manual or eight-speed automatic
Drivetrain
RWD or AWD (xDrive)

The B58 is a new engine and not an update of the N55. It has a robust closed-deck aluminum engine block made for high-boost turbocharged applications, as well as a narrower bore and longer stroke, although it still displaces three liters. It produces the same power and torque as the twin-turbo N54 engine in the former E90-based 335is models, but with a single turbocharger. It is used in the 2016+ 340i and replaces the N55 engine in the 2012-2015 335i.

N55 3.0-liter Turbocharged Inline-Six Hybrid
335 hp | 332 lb-ft
Horsepower
300 hp
Torque
300 lb-ft
Transmission
Eight-speed automatic
Drivetrain
RWD
  • Drivetrain: RWD
  • Electric motor: AC synchronous electric motor
  • Horsepower: 55 hp
  • Torque: 155 lb-ft
  • Engine + electric motor system output: 335 hp/332 lb-ft

The ActiveHybrid 3 is one of BMW's first attempts at going hybrid. Power comes primarily from the N55 3.0-liter turbocharged six-cylinder, with improved performance and fuel efficiency courtesy of an electric motor and 1.3-kWh lithium-ion battery pack. It may seem like a good buy, but the additional power is offset by the additional weight, so it's barely any faster than the 335i. The ActiveHybrid 3 is not particularly efficient either, unable to beat the 320i's figures, and the claimed 2.5-mile electric-only range is of very little use. For 335i performance in exchange for 320i economy, it has its place in the range, but it's not a very convincing effort.

B48 2.0-liter Turbocharged Inline-Four Gas Engine
248 hp | 258 lb-ft
Horsepower
248 hp
Torque
258 lb-ft
Transmission
Six-speed manual or eight-speed automatic
Drivetrain
RWD or AWD (xDrive)

For 2017, a year after the 3 Series facelift, the mid-range 328i received a brand-new B48 2.0-liter turbocharged engine to replace the previous year's N20 engine and with it came a name change to 330i. Outputs are up marginally from 240 hp and 255 lb-ft to 248 hp and 258 lb-ft, but with improved gas mileage, emissions, and overall driveability. This particular engine is also used in the G20 3 Series and is well-known for being dependable. The AWD provides the same equipment levels, but with the added benefit of AWD traction; however, the 2017+ 320i and 330i are not available with the manual AWD option.

B48 2.0-liter Turbocharged Inline-Four Gas Plug-In Hybrid
248 hp | 310 lb-ft
Horsepower
180 hp
Torque
215 lb-ft
Transmission
Eight-speed automatic
Drivetrain
RWD
  • Electric motor: AC synchronous electric motor
  • Horsepower: 87 hp
  • Torque: 184 lb-ft
  • Engine + electric motor system output: 248 hp / 310 lb-ft

The 330e was BMW's second attempt at building a hybrid, but this one is a lot better. Firstly, it is a plug-in hybrid. Compared to its predecessor, its all-electric range is up from 2.5 to 14 miles and its fuel consumption figures are impressive - 31 mpg on the combined cycle in its normal gas-electric mode. It uses a 180-hp version of the B48 2.0-liter turbocharged inline-four gas engine and not the N55 six-cylinder of the old car. If you do want a hybrid, this particular model is much better than the older non-plug-in ActiveHybrid 3. Its 7.6-kWh lithium-ion battery pack can be fully charged in about two hours and 12 minutes from a 240-volt outlet. It sprints to 60 mph in a respectable 5.6 seconds, so it's a little slower than the ActiveHybrid 3, but a lot lighter on fuel.

While all engines were widely regarded as impressive, smooth, and efficient, time has proven the B-series engines found in the post-facelift 330i and 340i to be more reliable, while the N-series motors require more preventative maintenance to keep them running optimally.

For that reason, we highly recommend going for a facelifted model.

2012-2019 BMW 3 Series Real MPG

Looking at what's available on the used market, most customers chose to avoid the manual option available for the gas engines. The eight-speed automatic was a lot more popular, so we'll focus on that. Given the performance potential, all models come with impressive claimed EPA estimates and even more impressive real-life figures as you can see in the table below.

The Wagon is a little heavier than the sedan, but it makes no real difference to the fuel consumption figures.

EPA Estimated MPGReal-Life MPG
320i six-speed manual RWD (N20 engine 2013-2018)23/35/27 mpg36.9 mpg
320i six-speed manual AWD (N20 engine 2013-2018)22/33/26 mpgN/A
320i eight-speed auto RWD (N20 engine 2013-2018)24/35/28 mpg22-32.7 mpg
320i eight-speed auto AWD (N20 engine 2013-2018)23/34/27 mpg31.4 mpg
328d eight-speed auto RWD (2014-2017)31/43/36 mpg42.3-52 mpg
328d eight-speed auto AWD (2014-2017)30/40/34 mpg33.3-48.2 mpg
328i six-speed manual RWD (N20 engine 2012-2016)22/33/26 mpg26.3-31.7 mpg
328i eight-speed auto RWD (N20 engine 2012-2016)23/35/27 mpg30.8-31.3 mpg
328i eight-speed auto AWD (N20 engine 2013-2016)22/33/26 mpg25.3-32.6 mpg
330i six-speed manual RWD (B48 engine 2017-2019)21/32/25 mpgN/A
330i eight-speed auto RWD (B48 engine 2017-2018)24/34/27 mpgN/A
330i eight-speed auto AWD (B48 engine 2017-2018)23/33/27 mpgN/A
335i six-speed manual RWD (N55 engine 2012-2016)20/29/24 mpgN/A
335i six-speed manual AWD (N55 engine 2013-2016)20/28/23 mpgN/A
335i eight-speed auto RWD (N55 engine 2012-2016)21/31/25 mpg21.9-28.2 mpg
335i eight-speed auto AWD (N55 engine 2013-2016)20/30/23 mpgN/A
340i six-speed manual RWD (B58 engine 2017-2018)19/29/23 mpg27.2 mpg
340i six-speed manual AWD (B58 engine 2017-2018)19/29/23 mpgN/A
340i eight-speed auto RWD (B58 engine 2017-2018)21/32/25 mpgN/A
340i eight-speed auto AWD (B58 engine 2017-2018)21/31/25 mpgN/A
ActiveHybrid 3 eight-speed auto RWD (2013-2015)25/32/28 mpg38.3 mpg
330e eight-speed auto RWD (2016-2018)30 mpg/72 MPGe + 14 miles EV range46.4-75.6 mpg

* 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.

Safety

German manufacturers tend not to include advanced driver-assistance systems as standard. Once you start shopping around, it's worth checking whether the previous owner added the Driver Assistance Plus Package (only available post-facelift), which came as standard with speed-limit information, active driving assistant, lane-departure warning, forward-collision warning, pedestrian warning, city-collision mitigation, active blind-spot detection, and side- and top-view cameras. The basic standard features you'll find on all models include automatic headlights, rain-sensing wipers, and active and passive safety features like six airbags, traction and stability control, and ABS.

US NHTSA Crash Test Result

Overall Rating::
(5/5)
Frontal Barrier Crash Rating::
(4/5)
Side Crash Rating::
(5/5)
Rollover Rating::
(5/5)

6th Generation BMW 3 Series Trims

Most models in the 3 Series range came with a baseline specification, such as climate control, a rearview camera, an infotainment system operated via iDrive, and the previously mentioned safety features. BMW did this so buyers could spec their own cars. This meant they could buy a 340i with fewer features at a reasonable price, or equip a 330i with loads of features while keeping the price relatively low. The 2015 F30 gets standard Bluetooth audio streaming across the board and the 2016 facelift has improved suspension to optimize the ride and handling. Packages and options were shuffled around every year, with most of them being available on the top trims.

320i
2013-2018
Engine
2.0-liter turbocharged four-cylinder
Transmission
Six-speed manual, eight-speed automatic
Drivetrain
RWD and AWD

The entry-level 320i only joined the lineup for the 2013 model year. Standard features on the pre-facelift model include 17-inch alloy wheels, leatherette upholstery, eight-way manually adjustable front seats, a leather-trimmed and manually tilting/telescoping steering wheel, automatic halogen headlights, fog lights, rain-sensing wipers, cruise control, Bluetooth, a 6.5-inch iDrive infotainment touchscreen, HD radio, an iPod/USB interface, an auxiliary audio jack, and dual-zone climate control. The N20 engine was replaced with the B48 after the facelift, benefitting from the same upgrades the rest of the line-up received but with the same outputs. The Sport Line specification is included as standard on the facelifted 2016+ 320i, and you get the basic comfort and convenience features.

328i
2012-2016
Engine
2.0-liter turbocharged four-cylinder
Transmission
Six-speed manual, eight-speed automatic
Drivetrain
RWD and AWD

The 328i has the same basic equipment as the base 320i, save for the addition of a standard universal garage door opener, auto-dimming rearview mirror, power-folding side mirrors, eight-way electrically adjustable front seats (with a memory function for the driver), a backup camera, and a rear-seat pass-through. Further to this, the 328i had a more substantial options list so you have a better chance of finding a 328i with additional features than a 320i with all the niceties added. The 328i is one of three available engines for the Wagon. The sedan and Wagon trims are exactly the same, though the Wagon is only available with all-wheel drive.

328d
2014-2016
Engine
2.0-liter turbocharged four-cylinder diesel
Transmission
Eight-speed automatic
Drivetrain
RWD and AWD

Equipment levels mirror those of the 328i in all aspects, including standard power front seat adjustment, and optional features like a premium sound system, navigation, heated front seats, and blind-spot monitoring. You also find the Wagon in 328d trim, but only with the xDrive AWD system as standard.

335i
2012-2016
Engine
3.0-liter turbocharged six-cylinder
Transmission
Six-speed manual, eight-speed automatic
Drivetrain
RWD and AWD

Several features come standard at this level, including 18-inch alloy wheels, a power moonroof, an alarm, an auto-dimming interior rear-view mirror, and adaptive xenon headlights with auto-leveling and auto high beams. Otherwise, many of the same options were available, meaning you can have a basic car with a big engine, or you could opt for the full luxury affair.

ActiveHybrid3
2013-2015
Engine
3.0-liter turbocharged six-cylinder
Transmission
Six-speed manual, eight-speed automatic
Drivetrain
RWD

The ActiveHybrid 3 has the same specification level as the 335i. There are a few additions, like a model-specific coasting feature.

330i
2016-2018
Engine
2.0-liter turbocharged four-cylinder
Transmission
Six-speed manual, eight-speed automatic
Drivetrain
RWD and AWD

Featuring updated design elements, LED headlight availability, and retuned steering and suspension, the 330i represents a substantial leap forward. Updated features include the availability of items like a head-up display, adaptive cruise control, and a WiFi hotspot, along with new connectivity features such as Apple CarPlay. The 330i is the base trim for the Wagon. BMW did not offer an entry-level model for the Wagon, knowing that it was targeting a specific audience. All Wagons come standard with AWD.

330e iPerformance
2016-2018
Engine
2.0-liter turbocharged four-cylinder with hybrid assist
Transmission
Eight-speed automatic
Drivetrain
RWD

The specification of the 330e is identical to the 330i. The 330e has model-specific alloys and a 14-mile all-electric driving range.

340i
2016-2018
Engine
3.0-liter turbocharged six-cylinder
Transmission
Six-speed manual, eight-speed automatic
Drivetrain
RWD and AWD

The 340i carries over many of the features the 335i has such as a power sunroof, and also standard LED headlights, satellite radio, and a premium sound system.

Sixth Generation BMW 3 Series Features

320i328i335i330i340i
Back-Up CameraSSSSS
Bluetooth ConnectionSSSSS
Leather SeatsN/AN/AN/AN/AS
Apple CarPlayS on faceliftS on faceliftS on faceliftS on faceliftS on facelift
Keyless EntryN/ASSSS
Keyless StartSSSSS
HD RadioSSSSS
Alloy WheelsSSSSS
SunroofN/AN/AN/AN/AS

Interior, Trim And Practicality

BMW kept the standard features on the 3 Series to a bare minimum, which means there's a good chance you'll find a 335i or a 340i with cloth seats. Most people opted for the optional leather, which was available in the standard black, white, tan, and red. The F30 3 Series does not have the best reputation when it comes to interior quality. BMW ensured that the surfaces you interact with the most are covered in high-quality materials, but if you look closer you'll spot some cheap plastic.

The 13 cubic foot trunk is a nice addition. It can easily swallow two golf bags, a week's worth of groceries for a family of four, or the same family's luggage on a weekend away. The latter will require some careful packing, however. While BMW marketed the car as a five-seater, it's not. The rear middle seat has no legroom, which makes this a strict four-seater. If you want the ultimate in practicality, look no further than the Wagon. You'll only find this model with the 328i, 328d, and 330i engines, which come with a premium. For additional useability, the Wagon is only available with BMW's stunning xDrive AWD system. Good luck trying to find one, as the average car buyer seems to be allergic to wagons, opting for a crossover instead.

The Wagon retains the trademark BMW interior but obviously adds a much bigger trunk. The 17.5 cubic feet of storage space behind the second row is extremely useful. Fold the second row forward, and you get 53 cubes to play with. Cargo is more exposed in the Wagon, but a cargo cover is included as standard. Ensure you get this cover if you decide to purchase the vehicle. It's one of those things the previous owners might have removed to fit a bicycle, and forgot to put back in. You don't want any prying eyes looking at your valuables.

Trim320i328i/330i/328d335i/340iActiveHybrid3330e
Black ClothSSSSS
Black Leather SeatsOOOOO
Tan LeatherOOOOO
White LeatherOOOOO
Red LeatherOOOOO

2012-2019 BMW 3 Series Maintenance and Cost

BMW's dealer network is not that large, but there are hundreds of independent specialists all around the country. If you do plan on using an independent service center, ensure they have the right diagnostic equipment. An average annual service costs anywhere between $150 to $400, depending on where you go. A major service can cost anywhere between $1,000 to $3,000. According to the BMW forums, the average cost is around $1,400 to $1,700 per year. This is definitely one car where a third-party warranty is recommended. Warranties are available for cars that are less than 15 years old. If the car you're looking at falls within that bracket, go for it.

Sixth Generation BMW 3 Series Basic Service

Engine Oil change

Oil capacity:

  • N20 2.0-liter gas engine: 5L (5.3 quarts)
  • B48 2.0-liter gas engine: 5.2L (5.5 quarts)
  • N55 and B58 3.0-liter gas engines: 6.5L (6.9 quarts)
  • N47 2.0-liter diesel engine: 5.2L (5.5 quarts)
  • Recommended oil type: Fully synthetic 0W-30
  • How often to change: 15,000 miles or 12 months
  • Average price: $67-$92, depending on the engine
Sparkplugs
  • N20 2.0-liter engine:
  • Part code: 12-12-0-039-664
  • Average price: $111 for four
  • B48 2.0-liter and B58 3.0-liter engine:
  • Part code 12-12-0-040-551
  • Average price: $116 for four or $174 for six
  • N55 3.0-liter engine:
  • Part code: 12-12-0-037-582
  • Average price: $166 for six
Air Filter

OEM part number: ?

  • 13-71-8-507-320 for N20 2.0-liter gas
  • 13-71-8-632-502 for B48 2.0-liter and B58 3.0-liter gas
  • 13-71-8-511-668 for N47 2.0-liter diesel
  • 13-71-7-599-285 for 3.0-liter gas

Average price:

  • $39 for N20 2.0-liter gas
  • $51 for B48 2.0-liter and B58 3.0-liter gas
  • $72 for N47 2.0-liter diesel
  • $48 for N55 3.0-liter gas
Battery
  • Type: Non-standard battery
  • Replacement: Every 3 to 5 years
  • Average cost: $200
  • Service requirements: The BMW's ECU uses an intelligent battery sensor, which means you can't disconnect the old battery and fit a new one. The new battery needs to be registered by the car, which can only be done with the right diagnostic equipment.
  • 2013-2015 ActiveHybrid 3 1.3-kWh lithium-ion high-voltage battery pack average cost: $5,700
  • 2016-2018 330e PHEV 7.6-kWh lithium-ion high-voltage battery pack average cost: $1,393

6th Generation BMW 3 Series Tires

There is no standard tire size for the F30 3 Series since so many options were available. A 320i comes with a basic 16-inch rim, while the M Sport package adds larger rims and wider tires.

F30 models are infamously equipped with run-flat tires, but you don't necessarily have to go that route. Run-flats are notoriously stiff, so we recommend going with a basic tire repair kit and insurance with roadside assistance. We do recommend that you stick with the same tire size and wheels.

The various standard and optional tires for the F30 3 Series include:

2012-2016 328i RWD, 2013-2016 328i AWD, 2013-2018 328d RWD & AWD, 2013-2018 320i RWD & AWD, 2013-2015 ActiveHybrid 3 RWD, 2016-2018 330e RWD
Tire Size:
225/50-17
Run-flat all-season:
$780 to $1,228 for four
2012-2015 335i RWD & AWD, 2016-2018 340i RWD & AWD
Tire Size:
225/45-18
Cost for all-season:
$832 to $1,113 for four

Check Before You Buy

Technical Service Bulletins according to the NHTSA. Check service book for:

The 2012-2019 BMW 3 Series recall list is quite long. All early models were recalled for a PVC heater that may short circuit, increasing the risk of a fire. The 2012 model was recalled for head restraints that went beyond the maximum allowed movement in the event of a crash. 2012 and 2013 models were also recalled for driver airbag inflators that may explode. 2012 to 2014 models were recalled for loss of brake assist. 2014 models were subjected to a fuel pump recall. Later on, in 2021, all diesel models were recalled for the possible failure of the high-pressure fuel pump. 2012-2015 models were recalled for inoperative side marker lamps.

These are the error codes you'll most likely encounter when shopping for a sixth-generation BMW 3 Series:

  • Code P0030 indicates that there is a problem with the heater element circuit of the heated oxygen sensor.
  • Code P0597 is for a faulty thermostat. This is a serious issue, as it can lead to overheating problems.
  • Code P052B indicates that there is a problem with the Variable Valve Timing solenoid.
  • Code P0456 will show up when there's a leak in the EVAP system.
  • Code P0171 indicates that the car is running lean.
  • Code P0243 will show up when the ECU when it detects wastegate problems.
  • Code P0300 indicates a misfire in the engine.

There are several known 2012-2019 BMW 3 Series problems, but there is one failsafe way to avoid most of them. According to various BMW forums, buying a used F30 3 Series with a full service history is the safest bet. Check that all fluids have been changed, especially the transmission fluids on earlier cars. Here's another hot tip: buy a model with services that took place before reaching the scheduled intervals. These cars preferred preventative maintenance instead of regularly scheduled maintenance. There were a few persistent problems with the earlier N-code engines and we list them below. The later B engines are all-new, with robust closed-deck engine blocks made for high-boost turbocharged applications and so far, they seem to last well, but they're still quite new and one would have to keep an eye on them to see whether they develop the same problems as the N engines.

6th Gen 3 Series Common Problems

N20 and N47 Four-Cylinder Engine Problems

There seems to be some confusion about which 2.0-liter turbocharged F30 engine is which. All four-cylinder F30s started out with the N20 2.0-liter engine in 2012 and this engine was the only four-cylinder gas engine until the 2016 model year, when the 328i became the 330i and, in the process, lost its N20 engine in exchange for the then-brand-new B48 engine, still displacing two liters and with slightly higher outputs. However, the confusion comes in with the 320i, which retained the old N20 engine from 2016 onward, even though some sources insist that it also received the new B48 engine. A quick look under the hood appears to confirm that these sources are wrong and it is easy enough to distinguish the N20 from the B48. The N20's plastic engine cover has two cut-outs at its front end facing the nose of the car. If you're standing in front of the car with the hood open, looking rearward, the left cut-out is for the oil-filler cap and the one on the right for the oil filter. It also has a smaller plastic cover between the engine and the radiator which juts out noticeably in the center where it attaches to the front cross member close to the front bumper seal. The B48 engine looks quite different, with a more rounded and uniformly shaped main engine cover lacking the two cut-outs. The additional cover between the engine and radiator is also much larger, taking up almost the entire space, for a much more enclosed appearance. All this is quite important because the one to be wary of is the N20. The most common of the N20 engine problems is with the timing chain; in fact, almost all of the N20-engined models have known timing chain problems and issues.

The plastic timing-chain guides wear out prematurely and the chain starts making a whining sound when the engine is running, soon damaging the chain and requiring the entire timing-chain kit to be replaced. If ignored, the chain can fail and ruin the engine. This problem afflicts N20 engines up to 2015 and engines before that should be fitted with updated and improved parts to prevent the problem from happening. Some N20-equipped BMWs received extended seven-year/70,000-mile warranties, so either check the VIN to see whether a vehicle qualifies or make sure the pre-2015 N20 you're looking at has been fitted with the updated parts, with proof of the work having been done by BMW. With the timing chain sorted, the N20 is quite reliable, but it still suffers from oil leaks from the valve cover and oil filter housing, like most BMWs of this era. Vanos failure is also expected every 70,000 miles or so.

In terms of the N47 diesel engine, most of the timing-chain comments apply as well and these are often due to oil-change intervals being stretched out too far, but as this was a rare and unpopular model, avoid it altogether, because engine parts will also be scarcer and more expensive.

Mileage: Chain-guide failure from 50,000 miles, oil-filter-housing leaks from 60,000 miles, and valve-cover leaks start between 50,000 and 100,000 miles.

Cost: $1,500 for parts and labor to replace the timing-chain kit at an independent shop and double that amount at BMW; the parts for a valve-cover replacement are around $400 ($450 on the six-cylinder N55) and around $400 labor; an $800 job to replace the oil filter housing; $300-$400 to replace the Vanos solenoids.

How to spot: Failing chain guides will cause the chain to whine audibly or emit a grinding noise; valve-cover and oil-filter-housing leaks will leave visible traces of oil, even on the floor, and emit a burnt-oil smell and even some smoke when dripping on hot engine parts.

N55 Six-Cylinder Engine Problems

The turbocharged 3.0-liter N55 engine had become quite reliable by 2012 and the only real issues with it are persistent oil leaks from the valve cover and oil filter housing, like many other BMW engines, and failing water pumps and thermostats at higher mileages. The water-pump housing contains both the pump and thermostat and is prone to cracking at leaking with advancing age. Vanos failure from around 70,000 miles is also to be expected and requires replacing all the Vanos solenoids. Vanos lasts better with frequent oil changes.

Mileage: Water pumps and thermostats last around 80,000 miles at best but can start playing up before that.

Cost: The N55's water pump and thermostat cost around $1,000 to replace, labor included, and the Vanos job should cost around $400, all in.

How to spot: A thermostat will usually fail in the open position, leading to overcooling and error codes, while the water-pump housing may leak coolant, leading to low coolant levels and overheating, as well as visible leaks.

Damage to the dual-mass flywheel on manual transmission

This problem is limited to pre-facelift manual models. As part of the facelift, BMW strengthened these parts.

Mileage: Between 80,000 to 90,000 miles

Cost: $600 to $1,100

How to spot: Vibrations and knocks while driving

Automatic gearbox transmission fluid

A lot of automatic transmission and xDrive transmission problems were traced back to a lack of fluid. It may be necessary to check the oi levels of these components more frequently and keep the fluids topped up. We would replace automatic transmission fluid at least every 60,000 miles to maintain long-term reliability. Generally, the popular ZF 8HP automatic transmission is an excellent unit that can last well with the proper care.

Mileage: Problems can start at 60,000 miles if there are fluid leaks, so check the transmission fluid periodically and replace it at this distance.

Cost: $800

How to spot: Check the service history, check for oil leaks, and check the oil level at every service.

Starter motor failure

The F30 3 Series came standard with a stop/start system. These are notoriously rough on the battery and alternator, especially when the system does not deactivate when the battery voltage is low. Early cars suffered from starter motor failure due to batteries that were drained by the stop/start system. BMW's intelligent charging systems might not always fully charge the battery on short trips, so if you do a lot of town driving, it might be worth investing in a trickle charger to keep the battery topped up. Also drive sedately home the last few miles to give the engine the opportunity to cool down properly, so the cooling system won't have to do as much post-switch-off cooling, thereby giving the battery a rest and prolonging its life. These problems were magnified in BMW's 4.4-liter V8 N63 engine but remain true to a large extent to many modern engines with intelligent charging systems and with cooling systems that run after the engine has been switched off.

Mileage: 15,000 miles

Cost: $400 to $550 for parts, and $300 to $350 for labor.

How to spot: Check for irregular starter motor and battery replacement; best to avoid earlier models

Taillight seals

The 3 Series is known for rear light problems. The taillight seals are known to fail, causing moisture leakage into the trunk.

Mileage: N/A

Cost: $20

How to spot: Smell the inside of the trunk for that telltale musty water odor.

Less Common Problems

We found a few complaints about AC or air conditioning problems, but not enough to be considered common compared to the number of cars BMW sold. It's worth keeping in mind that the very first F30 models are now more than ten years old, and at some point, the AC will need a freon recharge. There were some complaints about 3 Series steering problems, but in most cases, the car just missed a service where the power steering fluid needed to be changed. There were some fuel-pump failures on the four-cylinder engines, but too few to warrant great concern. Random electrical problems can occur and the iDrive can be prone to bugs, although this is usually easy enough to fix with a software update.

Which One To Avoid

There are a few models to avoid. First and foremost, avoid the diesel. It had expensive problems, and you'll struggle to get parts for it. The N20 engine in the 328i and 320i is a bit fragile and we'd avoid it unless we had proof the timing-chain system has been replaced with updated parts. The ActiveHybrid 3 makes no sense, and the same goes for the 330e. The all-electric range is not impressive or usable, and the cost of replacing batteries after ten years or so is high and unlikely to be recouped in fuel savings.

Which One To Buy

For once, the fun model is the one to have. The 340i's upgraded 3.0-liter turbocharged six-cylinder is robust, and it's fun to drive. While most Bimmers of this era are sparsely equipped, BMW at least provided a power sunroof, LED headlights, satellite radio, and a premium sound system. Since it's a facelifted model, it also comes with Apple CarPlay, which you can use for live navigation via third-party apps. It's just a pity this engine was never offered in the Wagon because we'd have one of those in a heartbeat. If you can't stretch the budget that far, opt for a 335i. Just keep an eye out for a model that has been well looked after.

6th Gen BMW 3 Series F30/31 Verdict

The 6th generation 3 Series was a big departure from all the 3s that came before. It lost a bit of its edge, especially at the bottom end of the range. The six-cylinder models still provide plenty of thrills, however. While there are a few models to avoid, the most fun model is the one to have. The interior tech will be one generation behind what's available these days, but Apple CarPlay and mobile data will make living with it so much easier. The F30 3 Series is also large enough for a small family, and practical enough for the daily grind. If you want something a little bigger and more stylish, it's worth having a look at the BMW X3 from the same vintage, as it used the same basic platform and engine options.

Back
To Top