'05 Ford Focus, backend noise

Several weeks ago my car started making a noise that sounded like a motorcycle was coming up behind me. The noise started in at 65 mph and now, weeks later, starts in at around 35 mph. I have had the muffler checked and the CV joints and everything checks out okay. The noise does not change if the car is turning left or right. The noise is also, curiously, no louder with the windows open or closed. Any ideas welcome.

Take the vehicle for a drive while someone follows you in another vehicle and have them watch the rear tires on your vehicle. What you might be hearing is tire bounce.

Go to YouTube, and in their search engine type in “tire bounce” and you’ll see an example of tire bounce.

Tester

Thank you. I will do that this weekend.

When they checked the muffler, did they also check the rest of the exhaust system? This sounds like an exhaust leak somewhere, from a rusted or broken exhaust connection. Before this happened, did you recently run over something like a branch or a limb in the road and hear a clunk or scraping sound? When backing up, before all this happened, did you hear something in the bumping into a curb or rock? If the tailpipe or muffler hit something, while it might not damage those parts, the impact could be enough to crack something else in the exhaust system. If the noise seems to be coming from the front part of the car more than the back, suspect a loose or cracked exhaust manifold.

You might have a bad wheel bearing