As a professional mechanic with years of experience, I can tell you that there are several reasons why your Kenworth W900’s engine could be sounding louder than usual. It could be due to an exhaust leak, worn-out bearings, or even a failing transmission.
However, it’s hard to say without a proper inspection. I strongly recommend you take your truck to a qualified mechanic for a thorough check-up. A sudden change in engine noise should never be ignored as it could lead to more serious problems down the line.
Stay safe on the road!