Auto insurance policies are meant to protect your vehicle if it is damaged as the result of a covered loss. Unfortunately, breakdowns, wear and tear, and warranty issues are not covered on a traditional auto policy. If the vehicle's engine were damaged due to an accident then your collision coverage would pay for a new engine, but auto insurance doesn't cover a specific part.
You could purchase a "stated amount" policy for your vehicle which means you and the insurance company agree to a set value of your car in case of a total loss. However, this would require that the value be determined by an appraisal and usually has a much more expensive premium. These types of policies are better suited for classic or "show" cars since those usually aren't driven many miles per year. I hope this helps!