2000 V6 Camry Shaking / Vibration

I brought my used Camry to its first bumper-to-bumper inspection. They found everything in basically good health, so no work needed to be done. When I headed back home, though, there was a new shaking/vibration in the body of the car that wasn’t there before. The ride had been perfectly smooth up to that point. I figured the new vibration had something to do with the mechanic taking the wheels off and putting them back on. Alas, when I brought it back to them, they could neither feel the vibration during test-drive that I felt, nor could they suggest a cause.



'Any idea what the mechanic might’ve done, either during his inspection or while “putting my car back together” that could have created this new shaking/vibration that I feel in the body of my car? They used a pneumatic gun to remove and refasten my lug nuts. Could uneven torque pressure cause some kind of imbalance/misalignment that could result in shaking and/or vibrations? ?Any other possible explanations?

Did the vibration come back? Did they put the tires back in the original position? If they swapped the tires willy-nilly then they could have caused the vibration. Tightening the wheels with an impact wrench can warp the rotors enough to cause a vibration. The lugnuts need to be properly torqued.

It’s impossible to know what happened from here. Some theories could be a wheel weight falling off, moving wheels from one end of the vehicle to the other (some may not notice a vibration until it changes ends), installing wheels back onto a different lug position from where they were removed (this has to do with with rust scale on the hubs, possibly warped hubs, etc.).

Another possibility could be a shock or strut going weak after the car has been raised up in the air. This allows the shock or strut to reach its maximum extension and with an aged vehicle the seals in the shock/strut may be affected.
(This actually happened to one of my cars back before Xmas. I had raised the vehicle to change the engine oil, transmission fluid, check the brakes and suspension, etc. When I raised the car up the front struts were perfectly fine. When that car came back down both were perfectly bad and it rode like a ping-pong ball. So, new struts it got.)

Thanks for your questions and comments, missileman. Yes, the vibration returned. What is certain is that they did not rotate the tires after their inspection. Each one went back on where it came off. I’m kind of pinning my hopes on the lug nut torque theory at the moment. I’m going to wait a few days before having a mechanic remove and refasten them with a torque wrench to the correct pressure. The reason I’m waiting is contained in my answer to ok4450 below.

Yes, I realize my description is short on sufficient details. I simply don’t have more information at this point. Various possible explanations were what I was looking for, however, so thank you very much for your response. Your theory regarding a change in the shocks’ performance, after the car was put on a lift for the first time in who-knows-how-long, resonates with me. If overly-tight lug nuts are not the cause of the vibration, something tells me the act of removing all of the car’s weight from its own suspension may have disrupted the settle stability that had allowed it to ride smoothly up to that point. I’m not convinced that the shocks are actually “bad”, since the mechanic noted specifically that they were still in good shape, but I’m going to drive the car around for a few days and see if it resettles back into its stable suspension “state” and stops vibrating. If it’s still vibrating by the end of this week, I’ll turn it over to a different mechanic.