Why Does my Toyota Privias front end sound like its rumbling and going to fall apart. Les Schwab says the shocks and brakes are ok, brand new tires. And it idles horribly and wont start now im parked on a hill. While something other then oil is burning and smoking through the hood

Check the backing plate on the ft wheels

This is kind of a long shot, but you've done all the logical things already. You didn't state what make, model, year so I don't know if this will apply or not. I had a 2002 Intrepid that did this (infrequently at first, but became more pronounced) when I was turning slightly while braking. It turned out to be the inner tie rod ends, where they connect to the steering rack and pinion. The bushings were badly worn, and you could feel this with the wheels off the ground.

Check the warning sensor adjustment as the eb system may be worn enough to set it off if the adjustment is too close.

Be like a grinding nosise or a howling sound if howling like airplane then could be your rotors if a little jerking then it's both brakes and rotors but calipers themselves usually don't go bad les schwab will tell u for free if there good or bad before just throwing money at them k

could have wrong size tire or uneven,possible front brake caliper could be locking up.

Im not sure what car the instructions above are for, but it's not a Cressida. They dont have upper front control arms.

Anyways,

You remove the brake line, brake caliper, brake rotor. Then you remove the sway bar end link that attaches to the shock housing. Next remove the lower 2 shock bolts and the 3 upper mount bolts in the engine bay. Then you push down on the lower control arm so that you can remove the entire shock/spindle assembly.

Then take it to a shop to compress the spring to take it all apart.

Could be bad or sticking hubs, wheel bearings or u joints. When you said it went away when 4wd engages tells me that your right its partially engaged. Had the same issue with my 95 SUV 2yrs ago and had to replace the locking hub assembly. It had the electronic auto hubs. They were shot and starting to fall apart.

For some reason it doesnt think the alternator isnt working.

If you live near a Les Schwab then take it to them,the inspection is free, it sounds like you have ball joint that is coming apart or a tire that has separated,if you want to do it yourself then make sure the car is in park and chock the rear tires so it can't move then jack up the front end you can do one side at a time or both it's up to you just make sure to support the car on jack stands,once it is up off of the ground put one hand on the top of the tire and one on the bottom then try to make it move by pushing in at the top and pulling out at the bottom it shouldn't move then do the same thing on the side of the tire this will let you see if your tie rod ends are ok they shouldn't wiggle in there socket.Also check your tires for bulges or sharp steel belts sticking through the tread face.Hope this helps and good luck

Ok, so put that tire on the rear and see if the noise goes with it. Hope so, good luck-Ned-
Let your brakes break in before picking on them.