When should you change the cambelt on z3 1.9?

The cambelt on a BMW Z3 1.9 should typically be changed every 60,000 to 100,000 miles (approximately every 4 to 6 years), depending on driving conditions and manufacturer recommendations. It's essential to consult the owner's manual for specific guidelines. Additionally, if you notice any signs of wear or damage, such as cracking or fraying, it's crucial to replace it immediately to prevent engine damage. Regular maintenance checks can help ensure the cambelt is in good condition.