2003 V6 Sonata sounds like a diesel

[Churchie]

Had car in for motor cradle rust repair recall, mechanic said "oh by the way have you had timing belt changed (70,000 on car) said no..when call for status they said car won't start must be timing belt!!!!" Called Hyundai in CA got a call back that they would check it out and get back. Next day they said they changed oil and all is ok. Wife said car sounded a little noisy, I checked and it now sounds like a DAMN diesel!!!!!. This motor had been so quiet it sounded as if it wasn't running. When they checked timing belt could this have caused it to jump or????????????