This cam gear problem, if it is indeed a problem among all ecodiesel engines, is detrimental. An engine has what’s called a timing chain, which is driven off of the crankshaft and wraps around cam sprockets, so the camshafts can open and close the valves when they're supposed to. That’s why it is called a timing chain, as it ensures the timing of the valves opening and closing stays where it should. If the timing chain slips, the cams mistime, and if it happens to a harsh enough degree the engine simply won’t start anymore, because valves are (or will soon) be hitting pistons at that point. A mechanic will then charge thousands to rip apart the engine and reset the timing, or replace the timing chain altogether.