2002 Chevy Trailblazer growing noise

I took my car into get both motor mounts replaced. They were not very bad yet, but were vibrating my car. When I drove the car home I noticed my fan set on 2 just gave out a puff of air. The speed seemed to pick up then slow down again. I didn't touch the dial. It did this automatically. I thought maybe my fan was going out like it did before so I turned off the fan off. THe next day I heard a grinding about 5 seconds long and it happens every 30 seconds it seems. The grindng noise happens when the car is in park, when coming to a stop I hear it, and when driving. Is it safe to drive? Why is this doing this now only mometns from taking the car in to fix the motor mounts, did they screw my car up? Suggestions? I also notice when I turn to the left my car sometimes seems to make a popping noise. This has been doing this a little while but never the grinding noise. That only started after I got the engine mounts replaced?