The BMW M50 engine is the successor to the M20, and predecessor to the M52 engine. The M50 was used solely in the E34 520i and 525i, and the E36 320i and 325i. It is a straight six, or inline-6, coming in at either 2.0L (M50B20) or 2.5L (M50B25).In September of 1992, the engine received a technical updated (dubbed TU on the engine code) which added a single Vanos system. … [Read more...] about BMW M50 Common Engine Problems & Reliability Issues