Depends on the type of noise and where it's coming from.
Is it high mileage, has it been serviced regularly, any history of oil starvation, is it losing coolant? Is it a knock, rumble, tap, squeal, sound like an army tank?
It is, for obvious reasons, pretty difficult to diagnose "rough" via text, just take it to a garage, it'll take a mechanic about 3 seconds to diagnose!!
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