I recently purchased a 2006 Impala with 26K miles on it.

When driving around 40-50 MPH and my foot isn't on the gas, I hear a strange sound from the rear...too loud to be outside air. Its the LT (3.5L)...is it the exhaust, or possibly the wheel bearings? I can't help but think its one or the other. Previously I had a '00 Impala, and it didn't have the same noise...but it also had a single exhaust.

Any idea or similar experience?

 

It would be helpful if people wouldn't have to guess at what the noise sounds like.... more info.

 

^^^Sorry...didn't realize that I actually left that out...

It sounds like a "growl" or grumble coming from the rear....not sure if it's the exhaust (since they're duals) or if it's the rear wheel bearings.

 

when traveling 40-50.... are you going straight, or making a turn.
if making turns, are you going left or right.
Most wheel bearings Ive seen make problems- do it when they are under load- like turning.
You may want to get under the car and see if the exhaust systems hooks havent come loose.
Sisters 03 Impala had one of those hooks with a rubberband looking thing loose on it... I simply put it back on....

 

My '06 Impala SS has a strange noise comming from the rear as well. It's great!! It is the roar of 303 ponies through a dual exhaust