I bought a 2007 XC90 several weeks ago. Within an hour of taking ownership, we realised there is a grinding noise to the front right (drivers side in Australia) upon acceleration at lowish speeds - it stops when the car is at cruising speed and I am not actively pushing the accelerator. Over the weeks we have owned it, it has got progressively worse - It now sometimes does it whilst idling (which it didn't do initially) and when I decelerate over bumps something in the same vicinity rattles - it sounds to me like the two noises are related.

It sounds like something is rubbing against something else, it is actually a noise I would associate with dodgy brakes, not accelerating.

It is absolutely driving me crazy with fear that I have got a car with a significant mechanical problem - I can't get it in with a highly reputable Volvo mechanic who has been recommended to me, until next week.

Does anyone have any thoughts about what it could be?

 

Your problems is as same as me. the worse of mine is the front right brake and wheel over heat with the rattling noise at low speed acceleration. I have not figured it out.

 

Turns out, our problem was a broken top engine mount. 15 minutes work and $400 and it was all fixed, such a huge relief. I hope yours is as simple.

 

If your brakes are good then it is your bearing . raise the tire from top to bottom and see if the tire rocking