Subaru Genuine Timing Chain Guide SINGLEYour engine's timing chain can stretch over time resulting in a check engine light that comes along with excessive noise from your engine's timing cover. If the chain has broken, which is a rare occurrence, the engine will not start. If your Subaru has high mileage along with any of these other symptoms, contact our service department for expert diagnosis. Note: Listing is only for single timing chain guide. Two required for full engine replacement.