The BMW S85 engine, a naturally aspirated 5.0-liter V10, stands as one in every of BMW M’s most bold engineering feats. Developed for the E60 M5 and E63/E64 M6, the S85 was impressed by BMW’s Formulation 1 experience within the early 2000s, showcasing a high-revving design, unbelievable sound, and motorsport know-how. Whereas revered by fanatics for its efficiency and character, the S85 additionally comes with a repute for top upkeep calls for and potential reliability issues. This text dives into the S85’s execs, cons, reliability, tuning potential, and upkeep wants.

Professionals of the S85 Engine

  • The S85 produces 500 horsepower at 7,750 RPM and 384 lb-ft of torque at 6,100 RPM.
  • With an 8,250 RPM redline, the engine delivers thrilling high-revving efficiency, making it a standout in its class.
  • Borrowing from BMW’s Formulation 1 experience, the engine options superior supplies and know-how, together with particular person throttle our bodies and a light-weight design.
  • The S85 delivers a novel exhaust notice, usually described as top-of-the-line in BMW historical past, mixing a high-pitched wail with a deep growl.
  • As BMW’s solely manufacturing V10 engine, the S85 holds a particular place within the model’s historical past and affords a novel driving expertise.

Cons of the S85 Engine

  • The S85 is liable to a number of points, together with rod bearing put on, VANOS solenoid failure, and throttle actuator issues.
  • Excessive oil consumption is frequent, notably because the engine ages.
  • The superior design and complex parts make the S85 troublesome and costly to restore and preserve.
  • Diagnostic and restore work usually requires specialised information and instruments.
  • Most S85-equipped vehicles had been paired with the SMG III single-clutch automated handbook transmission, which is thought for jerky shifts and frequent hydraulic pump failures.
  • Routine upkeep and potential repairs could be prohibitively costly, with rod bearing replacements and VANOS repairs being notably pricey.
  • The engine’s high-strung nature and gasoline consumption make it much less sensible for day by day driving, with common mileage usually within the single digits.

Reliability of the S85 Engine

The S85’s reliability is commonly debated. Whereas many homeowners take pleasure in trouble-free experiences with correct upkeep, others face vital points resulting from neglect or design flaws. Key issues embody:

  • Rod Bearings: Untimely rod bearing put on is among the most well-known points. BMW’s authentic bearings and oil clearances had been inadequate for the high-revving design, requiring replacements each 60,000–80,000 miles.
  • Throttle Actuators: The digital throttle actuators can fail resulting from worn gears, resulting in limp mode. Replacements are frequent at increased mileages. Some homeowners report early put on and tear on these.
  • VANOS System: The twin VANOS system is liable to solenoid failure, which can lead to tough idle, lack of energy, or test engine lights.
  • Cooling System: Cooling system parts, together with the water pump and thermostat, usually fail prematurely, risking engine overheating.
  • SMG Hydraulic Pump: House owners observed occasional hesitation throughout shifts occurred when the motor struggled to construct hydraulic strain shortly sufficient.
  • Serpentine Belt

Fashions Utilizing The S85 Engine

  • 2005–2010 E60/E61 M5
  • 2005–2010 E63/E64 M6
  • 2009–2010 Wiesmann GT MF5
  • 2009–2013 Vermot Veritas RS III

Tuning the S85 Engine

The S85 affords appreciable tuning potential, although its naturally aspirated design limits features with out vital modifications.

  • ECU Tuning: Software program tunes can optimize throttle response, take away the pace limiter, and refine energy supply, usually including 10–20 horsepower.
  • Exhaust Programs: Upgrading the exhaust can unlock a extra aggressive sound and minor efficiency features, notably with headers or catless setups.
  • Compelled Induction: Supercharging is a well-liked route for these looking for substantial energy will increase. Aftermarket kits can push output past 700 horsepower, however require vital funding and supporting modifications.
  • Weight Discount: Because the S85 is already extremely optimized, efficiency enhancements also can come from decreasing car weight reasonably than engine upgrades.
  • Consumption Modifications: Carbon fiber airboxes and high-flow filters can enhance airflow and improve the engine’s induction noise.

Upkeep Suggestions for the S85 Engine

  • Rod Bearing Alternative: Proactively change rod bearings to stop catastrophic engine failure. Contemplate upgraded bearings with improved clearances and high-performance oil.
  • Oil Adjustments: Use high-quality artificial oil (10W-60 is beneficial) and alter it each 5,000 miles to reduce put on.
  • VANOS Upkeep: Usually examine and change VANOS solenoids and seals as wanted to take care of optimum efficiency.
  • Throttle Actuator Alternative: Monitor throttle actuators for indicators of failure and change them with upgraded items when vital.
  • Cooling System Overhaul: Change the water pump, thermostat, and hoses at common intervals to stop overheating.
  • Transmission Care: If outfitted with the SMG transmission, service the hydraulic system and contemplate changing to a handbook gearbox for improved reliability and driving enjoyment.
  • Common Diagnostics: Carry out common diagnostics to catch potential points early. A dependable OBD scanner or BMW-specific diagnostic device is crucial.

The BMW S85 engine is a real engineering achievement, delivering distinctive efficiency, an unforgettable soundtrack, and an exhilarating driving expertise. Nonetheless, its intricate design and excessive upkeep calls for make it a difficult alternative for possession. With diligent care and common repairs, the S85 can present years of thrilling efficiency, however potential consumers needs to be ready for the related prices and occasional repairs. For many who are passionate and able to make investments the trouble, the S85 stands out as one in every of BMW’s most iconic engines, embodying the model’s wealthy motorsport heritage.