Little background, 2010 Volvo XC60 with 3.0 and 80k miles, I just replaced the PCV Engine Oil Catch, the left from CV axle and the brakes on all 4 corners on my son's car. The engine noise is gone, along with the clicking.

Now I still have an knocking noise. When I am standing outside the car with hood up or down. Press the accelerator. No noise. Sounds wonderful. Car actually runs really well and is very quiet.

Now move to driving the car. Every time I accelerate there is a fairly loud knocking noise inside the car. This noise seems to go away the faster I accelerate. But comes back as soon as I do not have the pedal to the floor. When I decelerate the noise is the loudest.

I have no idea what to even look for. Loose something? Loose Hub Bearing? Something loose in dash?

I am lost. Please help.