Electrolytic capacitors have a fairly short lifespan, though, as little as 5 years in many applications. They gererally work or they don't, though, and aren't intermittant. So, preventative replacement of the cap isn't necessarily a bad thing, but the cause of the intermittant start is likely elsewhere.
One easy way to tell if a cap is going bad is if it's bulging or leaking electrolyte.
