Mine is a new 2012 XC90 with only 19,000 miles on it. It just started making a heavy 'thunk' sound coming from the rear when going over a bump, and feels like the shocks are not working, like an old car that 'bottoms out' when you go over a bump and the bumping sound is like a loose spare tire under the rear of an old pickup.

The problem is, I cannot reproduce this sound or behavior with any reliability. For instance, two days ago, right after this behavior started, I took it into the dealer and went for a test drive with the mechanic and was not able to get the sound to return. They did an inspection on the rack and cleared the car as okay. That evening, going into the mall entrance where there is a dip in the road, it made the loud sound again and acted the same 'loose without shocks' way.

I hate things that you cannot pinpoint.

My guess right now is that it is something to do with the suspension, as it seems fine most of the time, then, just like the shocks have stopped working, it swings its rear down low when going over a bump and makes a loud sound 'thunk.'

Any guesses, I don't think the dealer will find anything since they already checked it out as okay, but I know there is something seriously wrong. This has been a very solid and quiet car for my little over one year of ownership now.

TIA,

Ken

 

the shocks would not momentarily stop working. if they are bad they would be bad all the time. you are probably hitting the bump stops (maximum shock travel). i'd check that the spare is tight and the tools/jack are secured and not bouncing around.