Does the BMW 3 Series have a timing belt or chain?

The BMW 3 Series utilizes both belts and chains, depending on which particular model year, trim level, and engine type You're looking at. For example, the BMW 325i uses a timing belt during the second generation (E30), which lasted from 1985 until 1993. Beginning with the third generation, they've exclusively used timing chains. The 320D has always used timing chains in each configuration, and the 320i has used chains exclusively, with the exception of the 1982-1992 2.0L M52B20. Glancing the list, is seems that the last time a timing belt was used on A3Series was 1998, with the 1,.8L M40 was used on the 318i. Therefore, if Your 3 Series is a modern model year, there's a good chance it's driven by a timing chain.