BMW N45

The BMW N45 is a naturally aspirated, inline-four gasoline engine produced by BMW from 2004 to 2011. It is a successor to the BMW N42 engine and features Double-VANOS (variable valve timing) but lacks Valvetronic (variable valve lift) which was present in its predecessor. The N45 was primarily used in lower-end BMW models sold in Europe, Asia, and other markets where smaller displacement engines were more common.

The engine was available in two main variants: the N45B16, a 1.6-liter version, and the N45B20, a 2.0-liter version. The N45B16 was commonly found in the BMW 116i, while the N45B20 was found in the BMW 120i and 320i models depending on the market.

Key features of the BMW N45 engine include:

• Inline-four configuration: A four-cylinder engine with cylinders arranged in a straight line.
• Double-VANOS: BMW's variable valve timing system for both intake and exhaust camshafts, optimizing engine performance and efficiency.
• Aluminum engine block and cylinder head: Contributing to a lighter engine weight.
• Electronic throttle control: Providing precise throttle response and improved engine management.

While generally reliable, the N45 engine can be susceptible to issues such as timing chain problems, oil leaks, and issues related to the VANOS system. Maintenance and regular servicing are crucial to ensure the longevity of the engine. The lack of Valvetronic was intended as a cost-saving measure, simplifying the engine design while still offering decent performance for its intended applications.