The timing chain set has many components, like chain damper, tensioner, guide or rails. Each of them is important for the whole set, and you have to make sure everyone one is in top shape so that they can cooperate properly. If your BMW is taking a worn timing chain guide, you may hear a clattering noise from time to time. You should stop driving, and check it immediately and see if the replacement is necessary. What's more, don't wait it is too late, and you are supposed to do regular maintenance to see every part in your BMW is working. Once you decide to change, you are glad to be your first choice and we offer you all BMW genuine OEM timing chain guide with a discounted price.