Hello everyone. I have a 2005 a4 with the 3.0. Let me start by saying the car runs great, it accelerates fine and there doesn't seem to be any loss of power at all, but when I am travleing at a slow speed and my rpms reach about 3 or 4 thousand a really scary noise starts to happen. Its a mixture of grinding and groaning (honestly cant really describe it but its horrible). It is most noticable in 1st and in 2nd i really had to listen but its there. in all other gears i cant seem to hear it. The noise doesnt happen when i rev it up in neutral, only while in gear and it has no effect on the way the car drives. I rolled in first until i started hearing the noise then gunned it to see if anything would happen but it just seems to go away when i do that but it could be my exhaust noise drowning it out. I know this wasn't the best description but i have never heard anything like this in any car. If this sounds familiar to anyone or someone has the slightest idea of whats going on any feedback would be very much appreciated. Thanks.

 

Could be CV joint but if it's a manual trans, check the gear oil level in these locations. The Transfer gear box (the Quattro part). The Transmission. Both front and rear Differential housings. Could be low on juice. But any horrible noises like that in the gear box is not a good sign. If it's a CV joint, it's much easier and cheaper to fix. Check to see if the rubber boots that protect the joints on the inside at the differential and on the outside at the wheels are torn. There will be grease slung all over the area.. Torn boots will cause premature failure of the joint because dirt and water get in..