I have a violent vibration when accelerating especially up a hill or over 60 MPH. The vibration goes immediately away when I let off of the gas. My mechanic has replaced the following to no avail: L axle, L wheel bearing and front motor mount. He feels that the vibration is on the Left side of the car. I recently invested in the 100000 mile preventive maintenacnce, but now the car is hardly worth keeping. Any previous experience with this type of problem.

SOURCE: Why does my car vibrate and noisy at red light and stop sign

Maybe it's the transmission itself. check it.

SOURCE: I Think I have a front wheel bearing problem

Check wheel bering for play if there is no play , it doesn't mean that bearing is NOT bad its can still be dry and would be making that grinding sound you described Also check axle and see if boot is broken. That may be your problem also make sure that rotors are not gouged/scraped up and pads are good.Contact if you need more help and thanks for using FIX YA

SOURCE: Kia Sportage front wheel noise and vibrating

Sounds like a problem I had. Turned out to be the vacumn valve that locks the hubs when in 4wd. The car was not in 4wd but the hubs were always locked causing the wheels to vibrate and chatter especially when turning.

SOURCE: Knocking noise from under hood

ok the lifters are making noise, make sure you are using the right oil for your temp zone. also add some lucas oil to your engine oil, it will quiet down the engine.

SOURCE: 2001 kia sportage there is a grinding noise coming

dus it start win youre hiting bumps or turning or reach a sirtin speed