I was driving my mostly stock 2002 base coupe automatic ( I do have the 18/19 setup though) and had been out for about an hour with no issues. I came to a stoplight and when I pulled away it suddenly felt like the engine had a weird kind of vibration and the right rear felt exactly like I was getting a flat-- sort of a flop,flop,flop sound a tire makes when it is losing air. I thought " Oh great, this is all I need on a Sunday with my wife out of town". I pulled over to the side of the road and checked all of the tires but there was no sign of a low tire or anything foreign around or under the car. I figured that since I was only about 3 miles from home that I would just limp it there as carefully as I could. When I got back in the car an pulled away everything was back to normal again. I was completely baffled as to what just happened... There was never any warning lights or sounds and when I checked the codes there was only one for the RH door mirror. Has anyone ever experienced this phenomena before with their car? I have around 107K on mine and have addressed just about every thing that is a common problem with C5s including just recently the harmonic balancer. I don't drive mine hard except for an occasional blowout on the interstate and it is not a daily driver--just an occasional weekend cruiser. One thing I will add is that shortly after installing the new Potenza tires I had to put a plug in the right rear tire due to a screw and I at first thought that is what went wrong, but again no pressure was lost on any tire. Any ideas from you guys??

 

Sounds like debris, or a wheel well liner being loose, or your windows were down and it was just the wind buffeting.

 

Not on my C5, but on my CTS!! The rear passenger side tire had the belts start coming apart. My wife was driving ahead of my C5, and pulled off the road, saying she had a flat. She didn't, and I could find nothing wrong. So we traded cars, and sure enough, that's what it sounded like. I drove the car for maybe a quarter mile, and it disappeared. It returned a week or so later, and upon closer investigation, the steel belts were visible on the inside sidewall only. Have your tires X-rayed. I'd bet money you've got an internal break. I had 75,000 miles on my Continentals, so they were near the end. Had to buy 4 new ones. Hope this helps......

 

Moved to C5 Tech.

 

Most likely a rock stuck in the tread of your tire !!…find a rock and put it in the tread and go for a ride and see if that’s what it sounded like !!

 

If the car was at high rpm with the shifter in 1st or 2nd, you hit the rev limiter. Causes a symptom like a huge muti cylinder miss.