If your engine is sounding louder than usual, there could be a number of causes. First, check your oil level and quality - low oil levels can cause increased engine noise. If your oil looks clean and is at the correct level, then the issue may be with your exhaust system. A loose muffler or exhaust pipe can cause an increase in engine noise. If everything looks tight and secure, then the problem may be with your engine itself. Internal engine damage can cause increased noise levels. In any case, it's best to have a professional mechanic take a look to diagnose the problem and recommend the best course of action.