Your car will act like out of calibration when the timing chain is going out. That means that the piston-valve cycle is out of sync, and you'll experience frequent engine misfires. If the engine's timing isn't synchronized, it will imminently cause engine breakdown.u003cbru003eYou might also hear rattling noises when idle, so the u0022check engineu0022 light could be an early symptom to look for along with the sound.