Your BMW knock sensor is part of what keeps your engine purring as it performs its best. What it does, as the name implies, is to detect engine knocks, via the vibration that they make. The ideal ignition point for fuel in the combustion system is a burn that takes place just before the point of detonation, which is like an explosion. In some circumstance, such as when the timing of the burn or the air-to-fuel ratio is off, the fuel detonates, rather than burns, and when that detonation occurs, the vibration of it alerts your BMW knock senor to the existence of a problem. The BMW knock sensor then signals the main computer of the vehicle, when then sends out the necessary signals to adjust the timing of the burn and the air-to-fuel ratio, as needed. If the BMW knock sensor is not functioning as it should, then the vehicle computer is deprived of this valuable input, which can have serious consequences not only for vehicle performance, but also for the sensitive, and much more expensive, combustion system parts, such as the pistons, and other parts, such as the oxygen sensor and catalytic converter, which can both be negatively affected by the fumes resulting from an improper burn. Replacing the BMW knock sensor is a pretty simple repair, and when you make your selection from our vast inventory of aftermarket parts and accessories, readily available through our well-organized online catalog, it will be an affordable repair, as well. Finding the correct BMW knock sensor for your year and model is as easy as entering your basic vehicle information and making your selection from the list of suitable options that you'll quickly be presented with. You can order your BMW knock sensor online or via our toll-free telephone number.