Hello My name is Will and I have a 2007 Chevrolet Cobalt with 26700 miles on it and I have recently started hear some odd rattling noises from the back right tire area and I have looked under the car to make sure that there was not anything loose under there and I didn’t see anything. The tires on getting pretty worn out and I have order a whole new set, but I am still very worried about that noise and I was hoping someone could help me with this problem.
No one can help you remotely. Someone has to put the car on a lift and check it out. You’re unlikely to find it by just peering under there with all of the weight of the car on it.
If you have a spare tire/jack back there, it would pay to check to make sure that they are tight.
Make sure your lug nuts are tight, check to see if there might be something in the trunk just in case. It appears the exhaust is on the driver’s side to that seems to rule out exhaust clamps and heat shields etc. Most probably it could be a stabilizer link, or strut mount that may not appear loose. A good mechanic should be able to isolate and fix the noise.
You might be able to help yourself by raising one and then the other rear wheel off of the ground with a jack under a sturdy place under the car where it will not be damaged by the force of raising the car. Then shake the rear wheel in any direction that you can imagine. If that does not reveal anything, check your exhaust system to make sure that all mounting points are in place and as intended. Move the rear muffler around a little to make sure that it is not very close to touching any body part. Keep in mind that the exhaust system does have flexible mounts to permit some movement. Yes, I know it’s on the driver’s side but check it anyhow to eliminate that as a possibility.