The BMW S85 engine, a naturally aspirated 5.0-liter V10, stands as one among BMW M’s most formidable 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 fame for top upkeep calls for and potential reliability issues. This text dives into the S85’s professionals, cons, reliability, tuning potential, and upkeep wants.

Execs 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 singular exhaust be aware, usually described as probably the greatest 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 singular driving expertise.

Cons of the S85 Engine

  • The S85 is susceptible 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 complicated parts make the S85 troublesome and costly to restore and keep.
  • Diagnostic and restore work usually requires specialised information and instruments.
  • Most S85-equipped automobiles had been paired with the SMG III single-clutch automated handbook transmission, which is understood 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 gas consumption make it much less sensible for every day driving, with common mileage usually within the single digits.

Reliability of the S85 Engine

The S85’s reliability is usually debated. Whereas many house owners take pleasure in trouble-free experiences with correct upkeep, others face vital points attributable to neglect or design flaws. Key issues embody:

  • Rod Bearings: Untimely rod bearing put on is without doubt one of 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 attributable to worn gears, resulting in limp mode. Replacements are frequent at greater mileages. Some house owners report early put on and tear on these.
  • VANOS System: The twin VANOS system is susceptible to solenoid failure, which can lead to tough idle, lack of energy, or verify engine lights.
  • Cooling System: Cooling system parts, together with the water pump and thermostat, usually fail prematurely, risking engine overheating.
  • SMG Hydraulic Pump: Homeowners observed occasional hesitation throughout shifts occurred when the motor struggled to construct hydraulic stress 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 beneficial properties 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 Methods: Upgrading the exhaust can unlock a extra aggressive sound and minor efficiency beneficial properties, notably with headers or catless setups.
  • Compelled Induction: Supercharging is a well-liked route for these in search of 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 may also come from decreasing automobile weight somewhat 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. Take into account upgraded bearings with improved clearances and high-performance oil.
  • Oil Modifications: 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 keep up optimum efficiency.
  • Throttle Actuator Alternative: Monitor throttle actuators for indicators of failure and change them with upgraded items when needed.
  • Cooling System Overhaul: Substitute the water pump, thermostat, and hoses at common intervals to stop overheating.
  • Transmission Care: If geared up with the SMG transmission, service the hydraulic system and take into account 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 instrument is important.

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 selection for possession. With diligent care and common maintenance, the S85 can present years of thrilling efficiency, however potential consumers ought to be ready for the related prices and occasional repairs. For many who are passionate and able to make investments the hassle, the S85 stands out as one among BMW’s most iconic engines, embodying the model’s wealthy motorsport heritage.