Car is making a noise everytime I hit the gas...
 

First off, my apologies for contributing nothing but questions to the forum but I'm a new Audi dude and don't know jack about these things.

As for my 99 A6 2.8, if you can imagine the sound of someone sharpening a sword on a grinding stone, that's kind of like the sound it's making...or similar to dragging a metal can on the ground. Hard to explain, but it only happens when I give it gas, never when idling. Anyone experience this? No performance lags or anything, just a loud noise whenever I gas it.

Also, whenever I start the car after not driving it for 6 or more hours, there's a really loud fan that runs for a minute or two...it would seem to be like an "accelerated warmup" thing as I bought it in the winter, but at 70 degrees I don't know why it would do this...is it normal?

Maybe the exhaust rubbing on something... As for the startup fan...
 

that's the secondary air pump, which is an emissions thing. The inlet pipe may have come undone, which is why you can hear it so loudly.

The fan noise is due to the auxillary air pump to reduce emissions during startup.
 

How many miles on the car? Is it a Front Trak or Quattro? Got old service records?

Specifics: In gear or neutral? Does it change...
 

with engine speed? Could be an idler pully?

Re: Specifics: In gear or neutral? Does it change...
 

Only in gear, I can rev the engine in neutral and won't hear it...

Re: The fan noise is due to the auxillary air pump to reduce emissions during startup.
 

56K miles, Quattro, and unfortunately I don't have any old service recs...

So this fan noise is normal? Just seems weird, I'm hesitant to drive it until the fan calms down, though it really doesn't feel very different driving it while that aux. fan is still running...

Scraping noise...is it only when you give it gas from a stop?
 

if so, I might suggest you check your rotor shields, which are metal. The sheild is on the inboard side of the rotor, and sometimes warps and scrapes against the rotors. Easy solution, just reach in there and bend it back so it does not hit the rotor. Just be careful if you hove just driven the car around a lot, the brakes are HOT!

Just a guess...good luck!

Nope, anytime I hit the gas, but I will get under there and look
 

worth a shot, thanks.

Some fan noise is normal. As the other say, make sure the tube
 

is connected.

As for the grinding noise, can you tell where it comes from? Front, rear, center? You may have to drive alongside in another car with the windows down to identify the area.

Did it just start suddenly?

seems like it's gotten worse over the course of a couple months
 

and it's definitely coming from the front, somewhere around the engine, that's the best i can tell...