New member here. I have a 2005 A6 3.2 Quattro (45,000 miles). The engine seems rough and loud between 2000 and 2500 revs. Is this normal? Seems a bit unrefined for such a well respected engine. No other major problems to report.

If you are hearing clicking or hard engine noise at 2k-2.5k, I might be a bit concerned. Is it Dependant on accelerator position (more gas = more noise), or is it under load that you hear the noise, it's tough to even guess unless very specific conditions can be listed for us to read.

Thanks for your reply. The engine noise is under both hard and soft acceleration, always between 2 - 2.5k revs, irrespective of which gear I am in. The engine is smooth in all other rev ranges. Audi have old me twice that the engine is operating 'within the manufacturer's specifications'. This may be true, but as I said in my original post, it seems too rough a sound for such a well regarded engine.

I hear something similar when I first start up and drive away. The engine has a 12.5:1 compression ratio and direct injection. I've likened the noise to a diesel engine, when it's running at low rpm. What I suspect is that we're hearing the sound of the engine, and between 2000 and 2500 rpm there is not enough dampening in the car to quiet it. At 2500 rpm, the engine fires 7500 times a minute, or 125 times a second. That would be one octave below a middle C.

Once road noise rises, I no longer notice it, but, having come from an RS4 with Milltek exhaust, the A6 is too quiet for me.

It's hard to say w/o hearing exactly how it's like, but I found mine to sound pretty boring below 2.5-3k rpm. It doesn't sound like a special engine. Once past that speed range, the engine note changes completely & it screams to the redline effortlessly.