Greetings folks. I am in need of some help. First let me start off by saying I am newbie to this site and a complete engine car novice.

I have a 2003 a4 1.8t with 103,000 miles. I recently had an oil change, the whole cooling system replaced including the coolant pump. I had the timing belt and serpentine belt replaced as well. Car was running fine until I was driving for about an hour on the highway when the fine began making a loud sound when ever I increased the rpm's like it it was working overtime or the muffler was busted. Even at idle it has a louder than normal sound. No ticking or vibrations. Didn't notice any real loss of power, but the noise is def concerning. Please, please send some ideas my way! Many thanks