hello.. what you need to do is when it is making the roaring sound put it in park or neutral and rev the engine a few times a see if you hear the same noise..
i suspect you may have a bad fan clutch.. when they go bad the fan clutch can roar like an airplane taking off..
if you can try this and then get back to me if you need further assistance.. thank you
it sounds like a different issue with the ac light flashing..
whenthe ac light is flashing than the ac has detected a probelm in the ac clutch or ac electrical circuit.. there is a service bulletin on your ac compressor if you have rear ac also...
i would be pretty confident you have a bad clutch fan , the engine has to get warmed up to operating temp before the clutch fan will engage of lock so if it took a little while and then does it in park and on accel i would say that you need to replace the fan clutch..
hope that helps.. if you have the rear ac and want a copy of the service bulletin you would be out of warranty on this let me know and i can send it to you..
if you are just driving local trips it should be ok to drive.. keep an eye on the temp gauge because with the clutch fan roaring it is not pulling enough air through the radiator..
the bulletin i was pertaining to deals with the improved ac parts for your vehicle as some of the compressors were failing prematurely on your model i have attached the link dont know if that is your probelm or not..
Download link: http://www.mediafire.com/file/wmyzdmwixwy