The 2012 335i with N55 engine is a significant improvement over the troublesome N54 twin-turbo, but still carries BMW's characteristic high-mileage expensive failures. The single twin-scroll turbo is more reliable, but oil leaks, cooling system issues, and transmission problems define ownership past 80k miles.
Oil Filter Housing Gasket Leak
Common · medium severity
Typical onset: 60,000-100,000 mi
Symptoms: Oil pooling on top of transmission bellhousing, Burning oil smell from exhaust manifold heat, Low oil warnings between changes, Oil drips on driveway after sitting
Fix: Replace oil filter housing gasket and oil cooler seals while you're in there. 2-3 hours labor. Access is tight but doable without removing too much. Use OE gaskets only—aftermarket versions fail quickly.
Estimated cost: $400-700
Valve Cover and Valve Cover Gasket Oil Leaks
Common · medium severity
Typical onset: 70,000-110,000 mi
Symptoms: Oil residue along driver side of engine, Burning smell on cold starts, Oil consumption between changes, Failed emissions test due to evap system contamination
Fix: Replace valve cover gasket and PCV valve integrated into the cover. The N55 uses a plastic valve cover that can crack, so inspect carefully. 3-4 hours labor including cleaning mating surfaces thoroughly.
Estimated cost: $600-1,200
Cooling System Failures (Water Pump, Thermostat, Expansion Tank)
Common · high severity
Typical onset: 80,000-120,000 mi
Symptoms: Coolant warning light with no visible leaks, Overheating in traffic or on hot days, Coolant smell from vents, Expansion tank cracks visible on inspection, Erratic temperature gauge behavior
Fix: Electric water pump fails without warning—no weeping like mechanical pumps. Thermostat housing is plastic and cracks. Budget 4-5 hours to replace pump, thermostat, expansion tank, and hoses as a complete refresh. Do it all at once or you'll be back in six months.
Estimated cost: $1,500-2,500
Turbocharger Wastegate Rattle and Failure
Occasional · high severity
Typical onset: 90,000-130,000 mi
Symptoms: Rattling noise on cold start that disappears when warm, Reduced boost pressure and sluggish acceleration, Check engine light for underboost codes (30FF, 30FE), Turbo whine under acceleration
Fix: Wastegate actuator arm bushing wears out, causing rattle and boost control issues. Can replace just the actuator if caught early (6-8 hours), but often requires full turbo replacement. This is not a cheap fix—labor intensive due to location.
Estimated cost: $2,000-4,500
Timing Chain Guide and Tensioner Wear
Occasional · high severity
Typical onset: 100,000-150,000 mi
Symptoms: Rattling noise from front of engine on cold starts, Check engine light for camshaft correlation codes, Metal shavings in oil during changes, Rough idle that smooths out when warm
Fix: N55 timing chain issues are less common than N54 but still occur. Requires full front-end teardown—14-18 hours labor. Replace chain, guides, tensioner, and VANOS solenoids while you're in there. Oil change history is everything here—neglect accelerates failure dramatically.
Estimated cost: $3,500-5,500
Transmission Mechatronic Sleeve and Solenoid Failures (8HP Automatic)
Occasional · medium severity
Typical onset: 80,000-120,000 mi
Symptoms: Harsh shifts from 2nd to 3rd gear, Transmission fault warning on dash, Delayed engagement when shifting to Drive or Reverse, Limp mode activation, locked in one gear
Fix: ZF 8HP transmission mechatronic sleeve seal leaks internally, contaminating solenoids. Can sometimes be fixed with fluid and software update if caught early (3 hours), but usually requires mechatronic replacement (8-10 hours). Fluid changes every 40k miles prevent this.
Estimated cost: $1,200-3,800
High-Pressure Fuel Pump (HPFP) Failure
Rare · high severity
Typical onset: 70,000-110,000 mi
Symptoms: Long crank time before starting, especially when hot, Rough running and misfires under load, Loss of power above 4,000 RPM, Fuel pressure fault codes (29D2, 29E7), Limp mode during acceleration
Fix: N55 HPFP is more reliable than N54 but still fails. Metal shavings from pump contaminate injectors, so replace fuel filter and consider injector inspection. 4-6 hours labor. Use OE pump only—aftermarket failures are common.
Estimated cost: $1,800-2,800
Owner tips
Change oil every 5,000 miles maximum with BMW LL-01 approved synthetic—extended intervals kill timing chains and turbos on these engines
Replace transmission fluid every 40,000 miles despite 'lifetime fill' claims—ZF 8HP longevity depends on fresh fluid
Inspect cooling system hoses and plastic components annually after 60k miles—replace proactively before roadside failure
Keep detailed service records—turbo and timing chain failures correlate directly with maintenance neglect
Budget $2,000-3,000 annually for maintenance and repairs after 80k miles if buying used
Buy one if you have a trusted independent BMW specialist and a $3k/year repair budget—fantastic driving dynamics, but ownership costs are real and unavoidable past 80k miles.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.
Fitment notes: AGM battery required; located in trunk right side; requires registration with vehicle computer after replacement
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Every control module on the 2011-2013 BMW 335i — where it lives, replacement time, and what it takes to program a replacement. Modules marked dealer / factory tool won't work after a part swap alone — budget for programming.
Aftermarket tool coverage varies by software version and vehicle build — treat "aftermarket tool" rows as "usually possible" and verify against your tool maker's coverage list before promising a customer. Spot a wrong location or hour? Tell us — corrections ship fast here.
AIR BAGS:FRONTAL:DRIVER SIDE:INFLATOR MODULE · 20V017000
2020-01-15 · EA15001
BMW of North America, LLC (BMW) is recalling certain 2008-2013 128i and 135i Convertibles, 128i, 135i, and M Coupes, 2007-2010 X3 30si and X3 xDrive30i, 2013-2015 X1 sDrive28i, X1 xDrive28i and X1 xDrive35i, 2007-2013 328i, 328i xDrive, 335i, 335is, 335i xDrive and M3 Coupes, 2006-2011 328i, 328xi, 328i xDrive, 325i, 325xi, 330i, 330xi, 335i, 335xi, 335i
xDrive and M3, 2009-2011 335D, 2006-2012 325xi, 328i, 328xi and 328i xDrive, 2010-2011 X6 ActiveHybrid, 2007-2013 328i, 335i, 335is, M3 Coupes, X5 30si, X5 xDrive30i, X5 xDrive35i, X5 48i, X5 xDrive48i, X5 xDrive50i and X5 M, 2009-2013 X5 xDrive35d and 2008-2014 X6 xDrive35i, X6 xDrive50i and X6M vehicles equipped with non-desiccated driver frontal air bag inflators containing phase stabilized ammonium nitrate (PSAN) that were used as interim remedy parts for previous Takata recalls. These inflators may explode due to propellant degradation occurring after long-term exposure to high absolute humidity, high temperatures, and high temperature cycling.
Consequence: An inflator explosion may result in sharp metal fragments striking the driver or other occupants resulting in serious injury or death.
Remedy: BMW will notify owners, and dealers will replace the driver air bag. On X5 and X6 vehicles, only the inflator will be replaced. All repairs will be performed free of charge. The recall began March 11, 2020. Owners may contact BMW customer service at 1-800-525-7417.
EXTERIOR LIGHTING · 15V520000
2015-08-17
BMW North America, LLC (BMW) is recalling certain model year 2012-2015 320i, 320xi, 328i, 328xi, 335i, 335xi, and ActiveHybrid3 vehicles manufactured October 20, 2011, to June 22, 2015, 2014-2015 328xi Sports Wagon vehicles manufactured March 21, 2013, to March 17, 2015, 2014-2015 328d, 328xd vehicles manufactured June 28, 2013, to April 21, 2015, and 2014-2015 328xd Sports Wagon vehicles manufactured July 5, 2013, to April 21, 2015. The affected vehicles may have been programmed with new software that inadvertently makes the front side marker lights inoperative in conjunction with the parking lights or the headlights. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 108, "Lamps, Reflective Devices, and Associated Equipment."
Consequence: If the side marker lights do not illuminate, the vehicle may be less visible at night, increasing the risk of a crash.
Remedy: BMW will notify owners, and dealers will upload revised software to correct the issue, free of charge. The recall began on October 7, 2015. Owners may contact BMW customer service at 1-800-525-7417 or by email at [email protected].
ENGINE AND ENGINE COOLING:ENGINE · 14V176000
2014-04-10
BMW of North America, LLC (BMW) is recalling certain model year 2010-2011 128i Coupe, 128i Convertible, 328i Sedan, 328i xDrive Sedan, 328i Coupe, 328i Convertible, 328i Sports Wagon and Z4 sDrive 30i, 2011-2012 135i Coupe, 135i Convertible, 335i Sedan, X5 xDrive 35i, and X6 xDrive 35i, 2011 335i xDrive Sedan, 335i Coupe, 335i Convertible, 528i Sedan, 535i Sedan, 535i xDrive Sedan, X3 xDrive 28i, and X3 xDrive 35i, 2010 X3 xDrive 30i, and X5 xDrive 30i, 2012 640i Coupe, and 640i Convertible and 2010-2012 535i Gran Turismo vehicles. In the affected vehicles, the bolts that secure the housing for the variable camshaft timing adjustment (VANOS) unit can loosen over time and may possibly break.
Consequence: If the bolts loosen or break the engine may have reduced power or stall. An engine stall increases the risk of a crash.
Remedy: BMW will notify owners, and dealers will replace the four VANOS housing bolts for both VANOS units (intake and exhaust), free of charge. In addition, owners of approximately 170,172 model year 2010-2012 BMW vehicles equipped with inline 6 cylinder engines not covered by this recall, will receive an extended warranty to address this condition. The recall began on September 24, 2014. Owners may contact BMW at 1-800-525-7417.
Size-standard part numbers — verify your connector type before buying. Rear blades are model-specific; check the package's vehicle list.
Fuel economy figures are EPA data via fueleconomy.gov (median across matching trims). Performance figures are compiled estimates for the 2012 BMW 335i 3.0L I6 Turbo N55 and can vary by trim.
🔧 Database maintained under the daily editorial review of Chris Hackleman · Master Technician · 20+ years and Jeff Moore · Master Lexus & Toyota Mechanic · 20+ years.