hi there

my car runs good, but there is sound comming only at higher rpm's, there is no smoke, no oil leak, but when driven hard it makes some noise at around 4500 rpm, is this normalor the turbo is going, 2nd gear pulls great, but around 4000 + rpm some drilling noise comes out of the engine, but when driving normal there is no sound what so ever, and i just did 115mph in sixt gear at around 4000 rpm or something like that but there was no noise, sometimes it feels like third gear is not pulling hard enough like the boost is much shorter then 2nd gear, but maybe iam just imaginaing things ?

 

Depending on the noise it could be anything from a turbo going out to transmission whine. Based on your description I would guess that its not a turbo though. The turbos on the A6 are fully spooled very early in the RPM range. Can you give a more detailed description of the noise and the timing of the noise (full throttle, only at high rpm, high pitched...ect)

 

the noise only comes at full throttle, and the noise increases its sound the more you accelerate, its like a drilling noise that increases only at high rpm, but when driving normal there is no noise at all, the noise disepears at higher speeds

 

Have someone check your ATF fluid level.