I have a 99 Cavaliar,and when I reverse and turn the wheel left I get a knock ,pop and have no clue what it could be. The Garage could find no problem physically.Any idea?????????????

 

I have a totally different car but I'll share my experience.

I had my 97 Subaru in the shop to get the driver's side CV boot replaced. After the CV boot was replaced I kept hearing a knock and a pop when the tires were cut at their hardest radius. Then one time there was a knock and a pop and the axle release from the driver's side wheel. Thankfully the Subaru is all wheel drive and I was able to limp back to the shop on the 40% power from the back tires.

Perhaps get them to check where your axles meet the wheels, and see if something is coming loose.

 

CV joint most likely, but could also be a strut bearing or a bad tie rod, ball joint or sway bar link...have a good shop take a look and test drive the car.

 

I say CV joint is bad as stated above, take it to another shop that will properly diagnose the problem and fix it

 

I had a 97 Z24 and i think you have the same problem i had. GM couldn't find it twice, neither could midas or cantire.
So, i just kept on driving it for 3 more years. Turn up the stereo....
Until the strut bearing at the top of the strut came apart.... Then it made a real good noise.

I put in all new struts, tie rods, ball joints, brakes, air compressor, etc.
And then sold it.

 

I'm going with strut bearing also. Mine was making noise/sticking about three years ago and when I asked my mechanic to look into getting it fixed (usually anything that looks half worn I get replaced immediately) he said "Sean, Um....you really might not want a price on this." Apparantly my car being a 2000 was right in the wrong year to have this problem because the bearing is super expensive. Any other year is no problem but my year is like brutal money.
After 70,000km's it has gradually gone away and barely sticks at all now.