Yes it is most likely the discs have had it, are they oem or after market! Get some high carbon discs if you want to upgrade as the chances of them warping are very slim and expell heat alot better. I run DBA 4000 series on the fronts and there amazing. Look in to those if you got some money to burn
Im getting the same thing in mine... i posted a thread up over the road and everyone was saying it will be the discs so im gonna change them along with new pads.
My std. discs warped half way through the first track day I did in my 5. I swapped to DBA floating discs and now more than a dozen track days since and killing a set of Pads on them they are still spot on J