Welcome to the BMW 1 Series Car Bible. As you scroll down you’ll learn all about this vehicle’s qualities, features, finer points, and shortcomings. If you’re thinking about buying one of these, want some help maintaining or modifying one, or just want to deepen your knowledge for the next round of car trivia, you’ve come to the right place.
This is a living document that’s updated as we learn and confirm new valuable info. Got something to add? Drop a comment or send us an email! Don’t be shy; the more dialogue we have the better this Car Bible will get.
–Andrew P. Collins, Car Bibles Editor-In-Chief
(Disclaimers; Disclosures: Some Car Bibles will have links to specific forums, groups, brands, shops, or vendors for parts shopping and such. We have no sponsorship deals or official affiliation with any of them unless explicitly stated. We also have to explicitly state that you should work on your own car and follow our advice at your own risk.)
There’s a lot of info packed into this Bible. If you’re looking for something specific, hit command/control-F, type one of these terms, and your browser should bring you straight in.
- The Short Story
- Fast Facts
- Spotter’s Guide
- Check This Car Out If…
- Important Trim Levels and Options
- Year-To-Year Changes
- Obscure Details
- General Reliability and Ownership Costs
- Red Flags and Known Issues
- Where To Buy Parts
- Aftermarket Support
- Popular Modifications
- Key Technical Details
- Fluids, Filters, and Capacities
- Factory Service Manuals
- Other References and Resources
- Professional Reviews
- Owner Reviews
- What They’re Worth Now
- Where To Find One For Sale
- What To Ask A Seller
- Competitors To Consider
- Photo Galleries
- Pop Culture References
- Enthusiast Inquiries
- Downloadable Paperback Car Bible
- Comments Disclaimer
The Short Story
The E8X BMW 1 Series, both the 128i and the 135i, were the Bavarian automaker’s entry-level models when they came to the United States in 2008. Both left a short while later in 2013 and were replaced by the 2-Series. The 1 was marketed around the world as a spiritual successor to the beloved-by-enthusiasts BMW 2002, a sporty coupe produced in the late-1960s and ’70s. This generation’s 1 Series is popularly referred to by enthusiasts as E8X, referencing the car’s chassis codes: E82 for coupes, E88 for convertibles. Hatchback models (E87; E81) never made it to the U.S. market.
The 1 Series cars we did get are generally still regarded as fun, engaging cars. They’re lighter and more compact than the 3-Series which they share some underpinnings with (the E9X generation), have either a naturally-aspirated or turbocharged inline-six under the hood, and are all rear-wheel drive.
If you’re looking for more images, scroll on down to the Photo Galleries links toward the end of the Car Bible.
The BMW 1er was the smallest offering during its run, and it shows. That shorter roofline, coupe-only body (for U.S.-market cars), short wheelbase, and more. It looks like a scaled-down BMW 3er, from its smaller headlights to its smaller Hofmeister Kink.
How does one ascertain whether they’re looking at a 128i or 135i? Generally, the 135i will have larger and wider wheels and tires, as well as a sportier-looking front bumper. Though, they can sometimes get confused for a 128i that’s equipped with the M-Sport Package, which has a similar-looking front bumper. Though, because basically everything is interchangeable between trims, owners might opt to put 135i wheels on their 128i, swap bumpers, etc.
The 1M was significantly different than the average 1 Series; we’ll write a separate Car Bible about it.
The 1 was one of the last BMWs to have hydraulic steering.
The E8X lived on in markets around the world – we only briefly saw it here in the USA.
It came with diesel engine options in other markets.
Shares around 60 percent of its parts with the E9X 3-Series.
Initially it was a bit tough getting a hold of confirmable production numbers. Scrubbing through the internet determined that BMW produced 156,451 1 Series of the coupe and coupe convertible variety between 2008 and 2010. That’s all well and good, but that’s world market, not USA-specific, only contains ’08-’10, and doesn’t include the more popular 135i. It also doesn’t cover automatic versus manual, each specific trim package, etc, so it’s tough to say how rare the car you own or are looking at really is.
Based on our research, we can say with confidence that M Sport package 128is, manual transmission-equipped models, and non-sunroof cars are unfortunately on the rare side. Finding a decent example with three pedals can be tough. Base automatic 128is are cheap and plentiful, though that might not be the best choice for an enthusiast who wants improved suspension and a manual gearbox.
Check This Car Out If…
You’re in the market for a small, fun, rear-wheel drive sport coupe. If you’d like to get behind the wheel of a real screamer, the 135i is well-known for being very responsive to power-adding modifications, and it has a particularly large aftermarket.
Important Trim Levels And Options
The 128i, 135i, and 135is were all available with both coupe and coupe convertible body styles, with various packages available to spruce up their amenities and appearances. The Premium, Technology, Limited Edition, Sport, and M Sport package were available on the 128i, while only the Technology and Limited Edition were available on the 135i. The 135is could only be optioned with the Technology Package.
Notably, one package worth pointing out was the M Sport available on the 128i. It included a red leather interior, better brakes, sportier 17-inch wheels, sportier shifter on manual-equipped models, a thicker/sportier steering wheel, sport suspension, and 135i front and rear bumpers.
These changes reflect the U.S. market.
2008 Model Year:
- Car debuts in the USA.
2009 Model Year:
- No significant changes.
2010 Model Year:
- Twin-turbocharging is dropped for a single turbo setup on the 135i’s N55 engine.
- Some folks argue that reliability went up after this point, though another opinion is that aftermarket tunability was negatively affected
- The 135i’s base wheels are now 17-inch staggered wheels, with (front) 205-50-R17, (rear) 225-45-R17 tires.
- The automatic transmission the in the 128i could now either be the ZF GA6HP19Z 6-speed auto, or GM GA6L45R six-speed auto, which was the only automatic offered on 2008-2009 models.
2011 Model Year:
- The automatic 135i is now equipped with the 7-speed dual-clutch transmission, the GS7D36SG.
2012 Model Year:
- No significant changes.
2013 Model Year:
- Final model year for U.S. market.
Luckily, the BMW 1 Series doesn’t have any obscure or odd maintenance requirements. Plus, a lot of what’s under the hood is very much the same as a lot of other BMWs of its era. Because of this, for a car company that suffers a brand tax on parts, its parts pricing isn’t too bad.
General Reliability and Ownership Costs
Generally 1 Series BMWs are expensive cars to run due to the parts costs. Though, ownership costs can be significantly cheaper if maintenance is of the DIY variety. That’s what we’re here for – helping you learn how to wrench, build up the confidence to perform maintenance, and save money!
Opinions vary a bit whether these cars would be considered “reliable.” Some owners point out that as long as service intervals are tended to, they’re fine. Some folks say improving cooling systems and changing the oil and oil filter more frequently significantly improves reliability. The general consensus is the 128i, while it has its own foibles, is more reliable than the 135i, mainly due to not being a direct-injection turbo engine.
Red Flags and Known Issues
Generally, because these are German sports coupes, they’ll need a tad more attention than other brands’ offerings from Japan and the USA.
Some of the 128i and 135i/s’ issues include:
Water pump and thermostat failure. The water pump is electric and is known to fail. Luckily, revisions were made and newer OEM parts are more reliable than ever.
Carbon buildup the intake valves. This is a byproduct of direct injection: gasoline doesn’t clean the back side of the intake valves, so carbon builds up in that area.
High pressure fuel pump failure. This was so bad that it was a 10 year or 120,000 mile warranty item; they tend to just fail!
Fuel injector failure. Due to the nature of the high-pressure fuel system, these can wear out faster than conventional injectors due to their increased workload.
Oil filter housing gasket leak. This is a common, albeit easy-to-fix leak.
Serpentine belt shredding. This system had some design faults, and if they snap can really do some damage.
Valve cover leakage and valve cover cracking. This is partially due to high heat, and pressure under the valve cover, especially on 135is.
Oil pan gasket leaks. These just, well, leak.
Turbo rattle and failure. The twin turbos on the N54 are weak, and can fail if not properly warmed up before stomping on it. Increased boost pressure decreases their life significantly, requiring aftermarket solutions to fully cure this.
Staying on top of BMW recommended service intervals, performing “while you’re in there” maintenance, using quality replacement parts, changing oil frequently, keeping an eye out, and not driving these cars too hard before they’re up to operating temperature help stave off issues immensely.
There have been a couple of extended warranty items on 1 Series cars. Some of the most significant ones have to do with the N54-equipped 135i; the high pressure fuel pump and fuel injectors carry a warranty period of 10 years or 120,000 miles. Wastegate-related maintenance is at eight years or 82,000 miles.
As far as firm recalls, well, there are a few. The NHTSA’s website details them, and they include: potential explosion of the driver airbag inflator, faulty blower motor wiring that may result in a fire, PCV heater short that may result in a fire, driver’s front airbag creating metal shrapnel upon deployment, loose camshaft bolts, a total loss of electricity, sound insulation around the seat belt might ignite causing a fire, a faulty cooling fan motor that results in a fire, and faulty rear CV joints might cause a stall.
Luckily, since these are open recalls, they can be checked and remedied by any BMW dealership. Also, the newer the 1 Series is, the less issues they have. Only early models have the frightening fire risks, while 2013 model year examples might only need their airbags replaced.
Where To Buy Parts
Aftermarket and OEM parts support is still very good for these cars, especially those equipped with N54 or N55 engine.
Because the 1 Series shares so many parts with the larger and more mass-produced 3-Series (as well as other models in BMW’s lineup), the chances of replacement parts being readily available for years to come are very good.
Besides doing common brake and suspension upgrades, there’s a myriad of tuning available for N54 and N55-equipped 1ers; ECU tuning, turbo upgrades, intake manifold upgrades, exhaust and intake upgrades, and so on.
The 128i doesn’t have as much going for it, besides intake and exhaust upgrades. Though, there is one OEM upgrade that can bump up power significantly: the 330i “HO” intake manifold upgrade with accompanying tuning. While this can be a bit expensive, it yields as much as a 60 horsepower gain, which is frankly phenomenal for a naturally-aspirated, non-race engine. Especially one that’s using other OEM BMW parts.
Key Technical Details
Engine: There were three U.S. engine options in these cars, one with two tunes:
- N52 3.0-liter inline-six, naturally aspirated (228 horsepower) in the 2008-2013 128i
- N54 3.0-liter inline-six, twin-turbocharged (302 horsepower) in the 2008-2010 135i
- N55 3.0-liter inline-six, turbocharged (302 horsepower) in the 2010-2013 135i
- N55 3.0-liter inline-six, turbocharged (322 horsepower) in the 2013 135is
Transmission: Four different transmissions saw duty in the U.S.-market:
GA6L45R is the six-speed conventional automatic in the 128i from 2008-2009, made by GM. This is actually tough territory to describe, as the ’08-’09 automatics were only the GM unit, which 2010-2013 could be this unit, or…
GA6HP19Z is another six-speed conventional automatic in the 128i from 2010-2013, made by ZF. Owners will have to be especially cognizant of which one they have, as they require different fluids and maintenance procedures.
the GS7D36SG seven-speed dual-clutch automatic, six-speed manual – 135i from 2011-2013.
The GS645BZ was the six-speed manual bolted up under manual 128i and 135is.
Drivetrain: Longitudinal front-engine rear-drive
Suspension: MacPherson struts, coil springs front and rear. 50/50 weight distribution with multi-link suspension at all four corners
Wheelbase: 104.7 in; 2659.38 mm
Overall length: 172.2 in; 4373.88 mm
Curb weight: 3,252 to 3,660 pounds, turbocharged and convertible models are on the heavier end, while non-turbo, non-convertible models are on the leaner-side
OEM tire size:
128i coupe, base: 205/50/R17
128i coupe, convertible: 205/55/R16
128i coupe, Sport Package: (front) 205/50R17, (rear) 225/45R17
135i coupe, 2008-2009 Base and convertible: 205/50/17
135i coupe, 2010-2013 Base: (front) 205-50-R17, (rear) 225-45-R17
135i coupe and convertible, Sport Package 18-inch: (front) 215/40/R18, (rear) 245/35/R18
Fluids, Filters, and Capacities
Fuel: The lowest acceptable octane rating for the 128i is 87, the 135i requires 89 or higher.
Engine Oil, 135i: 7 liters of BMW TwinPower Turbo 5W-30 Engine Oil, part number N54OCI. The recommended interval by enthusiasts is 5,000 miles, though BMW states 10,000. Err on the side of caution and do 5,000. Oil by brands like Ravenol and Liqui-Moly should be considered as well, as they’re renowned for being of OEM or better quality.
Engine Oil, 128i: 7 liters of BMW Twin Power Turbo (7.4 quarts), 0W-20 Engine Oil, part number 83212461988. The recommended interval by enthusiasts is 5,000 miles, though BMW states 10,000. Err on the side of caution and do 5,000. Like the 135i, oil by brands like Ravenol and Liqui Moly should be considered as well, as they’re renowned for being of OEM or better quality.
Battery Size: 70 AH. 570 CCA. Part number 61217586960, though this is discontinued from BMW’s parts catalog. Re-manufactured batteries are available though come with a core charge. Non-Lead Acid upgrades are always recommended, as they don’t leak, are lighter, and last longer. Braille’s B7548 is a good choice. Typically, batteries last 3-5 years depending on the climate. Shorter in hot climates, 5 years in colder climates.
Oil Filter, 135i and 128i: One BMW filter kit, 11427953129. This should be changed when you change your oil.
Air Filter, 135i: BMW Genuine, part number 13717556961. The Mann-branded product is a great, inexpensive alternative. BMW recommends this be replaced at 50,000 miles, though a visual inspection to ascertain how dirty it is should be priority. It might need to be replaced much sooner.
Air Filter, 128i: BMW Genuine, part number 13721730449. The Mann-branded product is a great, inexpensive alternative. BMW recommends this be replaced at 50,000 miles, though a visual inspection to ascertain how dirty it is should be priority. It might need to be replaced much sooner.
Cabin Air Filter: BMW Genuine, part number 64316946629, changed every 15,000 miles.
Manual Transmission Oil: 2.1 liters of 75W-90 Transmission Fluid, part number 83222339221. The recommended service interval is 50,000 miles.
Automatic Transmission Fluid, 135i automatic and 128i ZF automatic: 7 liters of Shell M1375.4 automatic transmission fluid, part number 83222220445. The drain plug and fill plugs, with accompanying washers, are also recommended replacements. The recommended service interval is 80,000 miles.
Dual Clutch Transmission Oil, 135i DCT: 6 liters of BMW DCTF 1+ Gear Oil, part number 83222446673. Again, doing a full service is recommended to keep this complex transmission happy. Companies sell service kits to make it easy. BMW states the fluid from the factory is “lifetime,” but enthusiasts recommend it be changed at least every 40,000 miles, included with a full service.
ZF Automatic Transmission Filter, 128i and 135i: BMW Part number 24117571217, this is actually a part of the transmission’s oil pan, and is recommended to be replaced when the fluid is replaced. Luckily, companies sell this service as a kit.
Differential Oil, Open: 1.2 liters of OEM Differential Fluid, part number 07512293972. Note: this is to only be used with open differentials that are not LSDs. The recommended interval is every 40,000 – 50,000 miles.
Coolant: Genuine BMW, part number 82141467704, diluted 50/50 with distilled water. Its recommended this be flushed and changed every 2 years. 1 gallon of coolant, equaling 2 gallons after dilution, should do the trick!
Power Steering Fluid: 2 liters of BMW Hydraulic/Power Steering Fluid, part number 83290429576KT. Enthusiasts recommend changing this every 30,000 miles, though BMW states its a lifetime fill.
Brake Fluid: OEM is BMW DOT 4 Brake Fluid, this comes in 335 ML bottles, and requires three bottles to do a complete flush. Part number: 81220142156. Upgraded DOT 5 fluid is always good for improved braking performance in non-cold climates. This is recommended to be changed every two years.
Clutch Fluid: This system integrates with the brake fluid.
Spark Plugs: OEM BMW spark plugs, six total, part number 12120037244KT. BMW states the service interval is every 40,000 miles, but some enthusiasts say 30,000-35,000 is a better idea.
Ignition Coil Pack: OEM BMW, six total, part number 12138657273. Enthusiasts seem to agree that the more often the plugs are changed, the less the Coils have to be changed. It also seems though, that 50,000 miles is “on the safer side.”
Carbon Cleaning: This affects 135is due to their direct injection. Carbon builds up on the backside of the intake valves, due to gasoline being injected directly into the combustion chamber instead of the intake manifold. This should be done every 30,000 miles, and luckily companies make DIY-friendly kits.
Factory Service Manuals
Bentley Publishers is considered the go-to for BMW factory workbooks, but bizarrely finding one for the 1 Series is somewhat challenging. A Haynes 1 Series manual exists but it’s not U.S.-model centric. This $13 downloadable “BMW 1 Series Workshop Manual” from emanualonline.com seems enticing but we haven’t tested it.
It looks like you can buy other downloadable manuals for this car at emanualonline too. Another site, aplusmanual.com, seems to have similar offerings and a site called onlymanuals.com has a bunch of free downloads but they’re mostly brochures.
If you just need a 1 Series owner’s manual, not a full FSM, bmwsections.com has free downloads.
Other References and Resources
We’ll add links to more critical resources as we find them!
“First Drive: 2011 BMW 135i Coupe. Bavaria’s Tiniest Model Loves Streets, Not Circuits” (MotorTrend – June 10, 2010)
Nate Martinez had some positive things to say about the 135i for MotorTrend in his 2010 solo review of it, right in the middle of its U.S. run. “With our right foot once again planted to its limits, corners hastily arrive at the nose. Turn (in) is sublime and weighty, just as it is in other roundel bearers.”
“First Drive: 2008 BMW 128i Coupe” (MotorTrend – February 18, 2008)
Edward Loh, at MotorTrend as well, had nice things to say about the 128i in 2008: “…the 128i is thrilling and proves you don’t need a ton of power to have a lot of fun, you just need to keep the momentum up. Near perfect 50/50 weight distribution helps accomplish this as does the 128i’s forged-aluminum front suspension pieces and lightweight steel multilink rear suspension. When fully compressed at the corner apex, there’s a feeling of massive tire grip at all four wheels — a wonderful sensation when these corners pile up one after the other as they do out here.”
Kevin Bandy (Jun 15, 2020)
2009 128i; modified; owned eight months plus
“The 128i is the newest and smallest of BMW’s naturally aspirated 6 cylinder cars with all of the suspension finesse of their higher trim cars. The lightweight package and low cost is a gem that’s often forgotten in the shadow of the quicker but less reliable 135i, or the highly valued 1M, but the chassis and potential is in tact.” That and more of his insights on 1 Series ownership are documented on his YouTube channel bandygram.
Jake Stumph (Feb 10, 2021)
2010 135i; modified; owned eight years plus
“I’ve owned my 135i since January 2013. It has taught me more about the way cars work than anything I’ve owned before or since. It’s deeply flawed, but something about it is so charming. It’s the last of its kind – with heavy hydraulic steering, a weighty clutch with a chunky shifter and a brutal twin turbocharged workhorse of an engine – and for better or worse that makes it feel so much more impactful to drive than anything BMW has made since. Are their cars now objectively better? Sure, they’re faster and more comfortable, but they’re sterile Germanic appliances by comparison. It’s most likely the last BMW I will ever own.”
Stumph has been an automotive journalist and track-day enthusiast for years. His YouTube channel has a mix of car reviews and mod tips, and you can see more about his 1 Series there too.
Own or owned one of these and want to share your thoughts? Hit up in the comments or email firstname.lastname@example.org!
What They’re Worth Now
As of 2021, on average, it looks like between private sales and used car dealerships of all calibers, the 128i ranges in price between $6,000 and $15,000, with the higher end occupied by manual models with the M Sport Package in very good condition and lower mileage. The lower segment is usually all 128is in rougher shape, with automatic transmissions and no noteworthy options.
The 135i/s goes for a bit more, hovering between $10,000 and $24,000 depending upon age, condition, options, mileage, and other standard factors.
The 1M, which again, we’ll dive into another time, is considered a collector’s item and worth dramatically more money.
Where To Find One For Sale
Because the 1 Series isn’t too old, you can still find examples for sale at popular used car dealers like CarMax and Carvana. However, Craigslist and Facebook Marketplace are full of them, as are clean, taken-care-of examples on various auction sites like Cars & Bids, Bring-A-Trailer, and more.
As with any used car purchase, the more prepared you are the better. At Car Bibles we’ve got some great reference material for navigating a used car purchase.
What To Ask A Seller
No matter what car you’re looking at, you’ll want to ask its seller about service history, remedying recalls, usage, condition, and why the car’s being sold. With the 1 Series, because there are quite a few components under the hood that are known weak points, pay close attention to topics like:
“When was the water pump and thermostat last replaced? Have they ever failed?”
“Have intake valves ever had any kind of carbon cleaning?”
“Has the high pressure fuel pump ever failed or been replaced?”
“Have you ever had an issue with fuel injectors?
“Has the oil filter housing gasket been replaced?”
“What’s the condition of the serpentine belt?”
“What’s the condition of the valve cover gasket and valve cover itself?
“Are there any oil gasket leaks?”
“Is there any turbo rattle? Has the turbo ever been replaced?”
Lower mileage doesn’t necessarily mean better mechanical condition; some of these could’ve been freshly replaced on higher-mileage examples.
For the 135i, one particular maintenance item to be sure to ask about is that above-mentioned intake valve cleaning. Since the N-series engines are direct injection, carbon buildup occurs on the backside of the intake valves, which can lead to a host of issues if not cleaned regularly. Opinions vary, but figure this type of service interval can be anywhere between 30,000 and 60,000 miles.
Competitors To Consider
Surprisingly, there isn’t a whole lot of direct competition to the 1 Series! The Audi A3 and S3 are probably the closest-thing-to. The A3 is more in line with the 128i as its the less performance-oriented model, whereas the S3 takes on the 135i.
The E9X 3-Series might be a consideration if you’re also thinking about something that’s a bit larger.
The Mazda RX-8 stacks up as a performance sports car with sub-250 horsepower like the 128i.
One could potentially also compare and cross-shop the Porsche Cayman and Cayman S to the 1 Series. The Porsches’ original MSRPs were significantly higher, and they have fewer seats. But depending on how flexible your budget is, if you’re sniffing around for “not terribly expensive rear-drive German fun cars” that might be on your radar.
The BMW Press Room always does at great job at this kind of stuff! Netcarshow has albums of the 1 Series Coupe from 2008 and 2012, the 2008 135i, convertibles from 2008 and 2012, plus 1 Series group shots.
Pop Culture References
As far as our research has dug up, not many celebrities have owned a 1er. Jodie Foster has, but that seems about it.
There 1-Series hasn’t really had any kind of prominent role in mainstream media. It had a minor appearance in an episode of Degrassi: The Next Generation (woopty-doo), but otherwise has mainly been in the background in movies and tv. Though it’s certainly had its share of appearances in automotive media.
Every car has a collection of common questions that pop up in forums and Facebook groups whenever new blood joins in. We hope a lot of those have been answered above, but if we start to see more specific questions pop up on the regular, we’ll include them in this section.
Downloadable Paperback Car Bible
If you’re old school and like to keep reference notes on paper, or you’re just a completionist and want a free accessory for your 1 Series, you can download a paperback Car Bible! Well, you have to also print it to put it on paper. But you knew what we meant.
Think of it like an owner’s manual supplement. Keep it in your car and your days of waiting for slow internet on your phone at the auto parts store are over!
You’ve reached the end of the BMW 1 Series Car Bible and are about to scroll into the comment section. If any questions were left unanswered in the text above, try posing it in the space below! Unsolicited 1 Series tips are also welcome.