My wagon has now started to make popping/ sounds knocking sounds while under load like the sound a bad axle makes when turning it only makes them while driving under hard load in turns sometimes in the straights I don't think its coming from the motor one front axle is new the other still has all its boots intact can it the old one be going bad with out a torn boot.

 

I had a similar noise it was the upper control arm, but I would check all suspension bushings and also recheck all the strut bolts and control arm bolts and engine mounts etc.

 

That would be one of your drive axle's.