The BMW S85 engine, a naturally aspirated 5.0-liter V10, stands as certainly one 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 lovers for its efficiency and character, the S85 additionally comes with a fame for prime 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 observe, typically described as the most effective 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 provides a singular 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 widespread, significantly because the engine ages.
  • The superior design and complicated elements make the S85 troublesome and costly to restore and keep.
  • Diagnostic and restore work typically requires specialised information and instruments.
  • Most S85-equipped automobiles have 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 may be prohibitively costly, with rod bearing replacements and VANOS repairs being significantly expensive.
  • The engine’s high-strung nature and gas consumption make it much less sensible for day by day driving, with common mileage typically within the single digits.

Reliability of the S85 Engine

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

  • Rod Bearings: Untimely rod bearing put on is without doubt one of the most well-known points. BMW’s authentic bearings and oil clearances have 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 widespread at greater mileages. Some homeowners report early put on and tear on these.
  • VANOS System: The twin VANOS system is liable to solenoid failure, which may end up in tough idle, lack of energy, or test engine lights.
  • Cooling System: Cooling system elements, together with the water pump and thermostat, typically fail prematurely, risking engine overheating.
  • SMG Hydraulic Pump: House owners observed occasional hesitation throughout shifts occurred when the motor struggled to construct hydraulic strain rapidly 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 provides appreciable tuning potential, although its naturally aspirated design limits positive aspects with out vital modifications.

  • ECU Tuning: Software program tunes can optimize throttle response, take away the velocity limiter, and refine energy supply, usually including 10–20 horsepower.
  • Exhaust Programs: Upgrading the exhaust can unlock a extra aggressive sound and minor efficiency positive aspects, significantly 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 automobile weight slightly than engine upgrades.
  • Consumption Modifications: Carbon fiber airboxes and high-flow filters can enhance airflow and improve the engine’s induction noise.

Upkeep Ideas for the S85 Engine

  • Rod Bearing Substitute: Proactively exchange rod bearings to forestall catastrophic engine failure. Take into account upgraded bearings with improved clearances and high-performance oil.
  • Oil Adjustments: Use high-quality artificial oil (10W-60 is really useful) and alter it each 5,000 miles to attenuate put on.
  • VANOS Upkeep: Frequently examine and exchange VANOS solenoids and seals as wanted to keep up optimum efficiency.
  • Throttle Actuator Substitute: Monitor throttle actuators for indicators of failure and exchange them with upgraded items when essential.
  • Cooling System Overhaul: Change the water pump, thermostat, and hoses at common intervals to forestall overheating.
  • Transmission Care: If geared up 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 important.

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