alright i have been having all sorts of problems with my 99 s80 lately i dont know if its related to the bad etm or abs module i have been dealing with but at around 3500 rpms on a stand still acceleration either in park or neutral the engines making a wierd rattle sound. any ideas on what it might be would be great thanks everyone.

 

Bad engine mount?

 

im having some similar issue with mine, Only that When I get up to 4k rpms and let it naturally slow down to its normal position, I hear lots of clicking noises....any ideas? Only notices this in tiptronic mode.

 

 

i had a toyota camry with a loose engine mount. i would hear a loud click sometimes during hard acceleration from stand still, when i would accelerate hard and let off the gas, when switching between forward/reverse with moderate acceleration after the shift and later, when it got worse, when it would change gears. basically, it seemed to happen whenever the torque from the engine and/or the resistance to it through the transmission changed. i never heard it rattle.

the mount had previously lost a bolt and i replaced it with one in my garage and it was fine for about 40k. i never actually checked to see why the mount was making this noise again, because it had plenty of other noises and i got my S80 shortly after it.
obviously the engine mounts in a volvo are completely different, but this sounds like it could be a similar problem. this is probably also why i never heard mine rattle, but it did have rattling in other places that i never tracked down.