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 engine 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

 

could be a whole bunch of different things. Not much forum traffic here in the "new member welcome area". you would be better served by posting your question in the A4 section where the "knowledgeable" members spend time.

good luck. have fun.

 

Have you confirmed that the exhaust system hasn't been compromised. I have heard that the exhaust system has a section of braided flex pipe that can break free and cause a leak.