that sounds like the same thing that I'm suffering from, but then again so do a lot of lower back/glute area injuries. You might want to golf ball or lacrosse roll your QLs that's where I also felt a lot of tension. Have you checked your psoas, that whole are seems to enjoy getting fucked. Funny thing is it's the exact same two exercises that aggravate it the most for me too, and only when going heavy.
Recently I have been doing a lot of bodyweight glute activation stuff (look up Bret Contreras), and it seems to be helping, but i've also laid off squatting and dl'ing pretty much completely. Do you warm up adequately? I notice leg swings across the body and back and forth loosed the hips up nicely followed by a long glute stretch (the standing newspaper hits the area best for me). Also try the standard IT band stretch (where you cross your feet and lean the opposite direction) but instead of just leaning, try and release the hip on the same side you're stretching and it also kinda hits that are.
Sorry if none of that made, sense. I just have a feeling that you are tight or injured or whatever in the same area I am. It sucks a ton since those are my two favorite lifts and I have not been able to go anywhere near the weights I used to for almost three months. Hang in there and focus on trying to stimulate your legs muscles with different techniques and such.