When does timing belt need to be changed in 2004 BMW x5?

The timing belt in a 2004 BMW X5 should typically be replaced every 60,000 to 100,000 miles, depending on the specific engine model. It's crucial to consult the owner's manual for the manufacturer's recommendations, as some engines may utilize a timing chain instead, which generally requires less frequent maintenance. Signs of wear, such as unusual noises or engine performance issues, may also indicate it's time for a replacement. Always consider having it inspected by a professional if you're unsure.