Hey, just to make some things clear. I have b5 98 a4 1.8t and on this model the rotors can't be turned? And if Im look for warpage what am I specifically looking for or what should I see? Thanks.

 

o yea its also quattro

 

Rotors can be turned..depending on how many times before it has been turned or it's current state. So far as warpage, you really won't be able to see with the naked eye while holding it in your hand. I suggest you take it to a shop and have them place it on the machine that turns rotors to see if it's warped or not.