BWMs are well manufactured and dependable vehicles. However, as with all vehicles, there is wear and tear over time which can lead to problems if proper vehicle maintenance is not performed. Do not ignore signs of wear and tear especially under the hood as it may indicate a serious problem with the timing belt.
Your engine’s crankshaft and camshaft have to run in sync with each other. The crankshaft is what’s connected to the pistons, via connecting rods, and actually delivers torque to the transmission. The camshaft is what opens and shuts valves during the combustion process, and the timing belt is what connects the two. Many vehicles use a timing chain (like a bicycle chain in a short loop) that runs on sprockets and will typically last the life cycle of the vehicle without needing replacement or service. The timing belt, like you might guess, is a reinforced rubber belt that will stretch and eventually snap over enough miles and years of time.
When the timing belt breaks, there’s no way for the camshaft to open and close the intake and exhaust valves, so the valves remain open. Remember that the combustion chamber at the top of the cylinder is quite small and tight; on some engines (known as “non-interference” engines), the piston can make it to the top of its travel in the cylinder without making contact with open valves. On other engines, the pistons can crash into the valves, resulting in bent valves and stems and perforated piston crowns. It’s a catastrophic scenario that means the end of that vehicle’s engine.
Most vehicle manufacturers specify a service interval of about 50-70,000 miles for timing belt replacement (check requirements for your year/make/model of BMW). The belt replacement is a fairly involved job that can only be done by a trained, experienced technician as it requires disassembly and removal of other engine parts and systems. Make no mistake: every mile that you go past the recommended timing belt service interval is borrowed time.
Don’t take chances. If it’s time for timing belt replacement for your BMW, contact the service department at Dreyer & Reinbold BMW North and make an appointment so that our factory-trained techs can get your service issue taken care of.
