The camshaft eccentric (or Valvetronic eccentric shaft) is a key part of BMW's Valvetronic system, and its role is a bit different from that of a standard camshaft. Here's a clear breakdown:

1. Purpose

• In a conventional engine, the camshaft opens and closes the intake and exhaust valves with a fixed lift and duration.
• BMW's Valvetronic system adds variable valve lift: it can change how far the intake valves open, which controls the amount of air entering the engine without using the throttle.

The eccentric shaft is the central part that makes this variable lift possible.

2. How it works

• The eccentric shaft is connected to a linkage mechanism attached to the intake camshaft.
• By rotating slightly, the shaft changes the angle of the intermediate rocker arms, which in turn changes how far the intake valves open.
• This allows the engine to:
  Improve fuel efficiency
  Reduce emissions
  Provide smoother idling and more precise throttle response

3. In short

• It doesn't directly turn the valves like a standard camshaft.
• It adjusts the valve lift dynamically, acting as a mechanical "volume control" for the engine's airflow.
• Works together with the camshaft, Valvetronic motor, and engine sensors to optimize performance.

OEM Part Number: 11377589883

Compatibility:

BMW 1 (F20) 2011 - 2019 125 i (N20 B20 A) - 160 kW / 218 HP

BMW 1 (F21) 2011 - 2025 125 i (N20 B20 A) - 160 kW / 218 HP

BMW 2 Convertible (F23) 2014 - 2025 220 i (N20 B20 A|N20 B20 B) - 135 kW / 184 HP

BMW 2 Convertible (F23) 2014 - 2025 228 i (N20 B20 A) - 180 kW / 245 HP

BMW 2 Coupe (F22, F87) 2012 - 2025 220 i (N20 B20 A|N20 B20 B) - 135 kW / 184 HP

BMW 2 Coupe (F22, F87) 2012 - 2025 228 i (N20 B20 A|N26 B20 A) - 180 kW / 245 HP

BMW 3 (F30, F80) 2011 - 2018 320 i (N20 B20 A|N20 B20 B|N20 B20 D) - 135 kW / 184 HP

BMW 3 (F30, F80) 2011 - 2018 328 i (N20 B20 A|N26 B20 A) - 180 kW / 245 HP

BMW 3 Gran Turismo (F34) 2012 - 2025 320 i (N20 B20 A|N20 B20 B) - 135 kW / 184 HP

BMW 3 Gran Turismo (F34) 2012 - 2025 328 i (N20 B20 A|N26 B20 A) - 180 kW / 245 HP

BMW 3 Touring (F31) 2012 - 2019 320 i (N20 B20 B) - 135 kW / 184 HP

BMW 3 Touring (F31) 2012 - 2019 328 i (N20 B20 A|N26 B20 A) - 180 kW / 245 HP

BMW 4 Convertible (F33, F83) 2013 - 2025 420 i (N20 B20 B) - 135 kW / 184 HP

BMW 4 Convertible (F33, F83) 2013 - 2025 428 i (N20 B20 A|N26 B20 A) - 180 kW / 245 HP

BMW 4 Coupe (F32, F82) 2013 - 2025 420 i (N20 B20 A|N20 B20 B) - 135 kW / 184 HP

BMW 4 Coupe (F32, F82) 2013 - 2025 428 i (N20 B20 A|N26 B20 A) - 180 kW / 245 HP

BMW 4 Gran Coupe (F36) 2014 - 2025 420 i (N20 B20 B) - 135 kW / 184 HP

BMW 4 Gran Coupe (F36) 2014 - 2025 428 i (N20 B20 A|N26 B20 A) - 180 kW / 245 HP

BMW 5 (F10) 2009 - 2016 520 i (N20 B20 A|N20 B20 B) - 135 kW / 184 HP

BMW 5 (F10) 2009 - 2016 528 i (N20 B20 A) - 180 kW / 245 HP

BMW 5 Gran Turismo (F07) 2009 - 2017 528 i (N20 B20 A) - 180 kW / 245 HP

BMW 5 Touring (F11) 2009 - 2017 528 i (N20 B20 A) - 180 kW / 245 HP

BMW X1 (E84) 2009 - 2015 sDrive 20 i (N20 B20 A) - 135 kW / 184 HP

BMW X1 (E84) 2009 - 2015 xDrive 20 i (N20 B20 A) - 135 kW / 184 HP

BMW X1 (E84) 2009 - 2015 xDrive 28 i (N20 B20 A) - 180 kW / 245 HP

BMW X3 (F25) 2010 - 2017 xDrive 20 i (N20 B20 A) - 135 kW / 184 HP

BMW X3 (F25) 2010 - 2017 xDrive 28 i (N20 B20 A) - 180 kW / 245 HP

BMW X4 (F26) 2014 - 2018 xDrive 20 i (N20 B20 A) - 135 kW / 184 HP

BMW X4 (F26) 2014 - 2018 xDrive 28 i (N20 B20 A) - 180 kW / 245 HP

BMW Z4 Roadster (E89) 2009 - 2016 sDrive 20 i (N20 B20 A) - 135 kW / 184 HP

BMW Z4 Roadster (E89) 2009 - 2016 sDrive 28 i (N20 B20 A) - 180 kW / 245 HP

What's in the box
1 x Eccentric Shaft