The timing chain tension keeps the right level or tension on the timing chain to keep it moving the same pace perfectly with the other parts of the engine. How to check if the timing chain tensioner in your BMW works well or not? If you hear some squealing or rattling voice from timing cover area; if you hear some chains flapping voice from the front engine when you stand one the side of pulleys when the car is running; if your car doesn't run at all, there should be a little slack on the opposite side of the tensioner. The timing chain tension in your BMW is too important to ignore. And please find a new one as long as you find there is something wrong with the timing chain tension. You can always find a good quality product here, and we promise we offer you all BMW genuine OEM timing chain tension at the lowest price.