Question: Tire problem

[LittleRedFlatBack]

I've got an issue that I'm trying to work thru with my C5. I've only owned the car for 3 months now, but I'm tired of the extreme noise in the cabin, generated by (I think) the tires. I've read thru many posts about run-flats versus non run-flats is this is NOT another post like that so read on before the flaming begins.

The noise is most noticeable in the rear of the cabin, so I assumed that it must be a rear tire causing the problem, but could find nothing wrong back there. Then I moved to the front of the car and found the beginnings of "cupping" on the inside of both front tires. I assume I need the front end aligned by this find. Now, here's the question part of this thread. 1) Can the front tires cause a loud roar throughout the vehicle and sound like it's coming from the rear and 2) Can I break-down the front two tires and swap the left/right tires on the wheels (thus moving the cupping to the outside of the wheels) to eliminate the road noise?

The car has 17's on the front and 18's on the rear so rotating is out of the question. My first thoughts were to replace all four tires with Michelin Pilot sport A/S (run-flats) after the alignment, but the tires are less than a year old (by the manufacture date) and I hate to spend the money if not required.

Dennis

 

[Patrick]

Dennis,
A couple of points for you to consider:

Run-flats, due the stiffer side wall construction, have a reputation for being noisier than non run-flats.

Yes, not only can you not rotate front tires with rear tires, you switch sides with the front tires, either. The tires are directional. When they wear, the only option is to replace them.

I don't have any specific experience with cupping on the tires, and the noise it would produce, but I suspect your analysis is correct: the cupping is most likely do to a bad alignment.

Hope this helps.

-Patrick

 

[LittleRedFlatBack]

Run-flats

Thanks for the imput Patrick.

I realize the run-flats are louder than other tires and this may very well be normal, but not owning the car since new puts me at a disadvantage here. I'm not sure if this is normal noise level or not. A friend that works at a tire company has told me that the cupping on the front tires can cause a lot of road noise too. My question is more directed towards moving the cupped section of the tire to the outside edge of the tire by swapping the tires from the wheels on the front of the car. Will tires cupped on the outside make the same noise as tires cupped on the inside?

Dennis

 

[gmjunkie]

Thanks for the imput Patrick.

I realize the run-flats are louder than other tires and this may very well be normal, but not owning the car since new puts me at a disadvantage here. I'm not sure if this is normal noise level or not. A friend that works at a tire company has told me that the cupping on the front tires can cause a lot of road noise too. My question is more directed towards moving the cupped section of the tire to the outside edge of the tire by swapping the tires from the wheels on the front of the car. Will tires cupped on the outside make the same noise as tires cupped on the inside?

Dennis

You can do that!!And get rid of the negative camber in the alignment!! Your tires will last allot longer!!

PS a little more air pressure in the front will help too!

 

[Tuna]

In my experience, once tires are 'cupped', you can't get them to quieten down short of having them shaved back to round.

Yes, it is also possible for the front tire noise to appear to be coming from the rear of the car.

 

[gmjunkie]

In my experience, once tires are 'cupped', you can't get them to quieten down short of having them shaved back to round.

Yes, it is also possible for the front tire noise to appear to be coming from the rear of the car.

Yep,I Agree!!

 

[LittleRedFlatBack]

Thanks guys, it's worth a try! These tires have too much tread on em' to just throw them away.

Dennis

 

[Tony C]

Hi All,
I had cupping on my front tires as well but they've been on for 32K miles. I'm replacing my original tires today with BFG g-Force super sport a/s tires (non-run flats). I got great mileage on the first set of OEM's but can't stand the noise, etc. Now, to your comment, I had someone suggest that when I replace the tires that I keep the old ones for autocross runs. I don't plan to do that but if your tires have a lot of tread left perhaps they can be "alternative use" tires.
Tony C.

 

[LittleRedFlatBack]

I don't plan to do that but if your tires have a lot of tread left perhaps they can be "alternative use" tires.
Tony C.

Good idea Tony, but I'm not really into autocrossing. I guess it would be a good excuse to get those Z-06 wheels I've been wanting because those "alternative use" tires would have to stay on my original wheels.

Thanks for the suggestion, Tony.

Dennis