Flat Spots on Tires

audi
a4

#1

I just went on a cross country road trip, about 10,000 miles, and now I have 3 very distinct flat spots on my rear driver side tire. They are on the inside tread and a scraped down to the threading in the tire. The car is AWD and the rest of the tires are getting close to being replaced but still have tread. I’m wondering what would cause this to happen. Any ideas? I checked the wheel well and there doesn’t seem to be any places where the tire would be rubbing.


#2

What you describe is not, technically, flat spotting. Flat spotting happens the whole width of the tread, and is usually caused by prolonged parking. What you describe sounds more like wear due to improper wheel alignment or suspension damage.

I suggest you have someone check the wheel alignment on your A4 before you install new tires.

By the way, if you can see the tire cord it’s not safe to drive on the tire. Have this checked ASAP before the tire blows out.


#3

The problem might be caused from a worn strut/shock at that corner. If the strut/shock has lost it’s dampening effect, the tire can start bouncing up and down as the vehicle is driven causing cupping or flat spots on the tire.

Take vehicle for a drive with someone following in another vehicle. And under various speeds have them observe that tire. If the tire starts bouncing up and down that strut/shock is worn and that’s what caused the flat spots.

Tester


#4

Also, any tire that’s worn down to the cords (the ‘threading’) is unsafe. You need to replace and balance the 4 tires, get the suspension checked for worn components, and have a 4-wheel alignment, ASAP.


#5

The car is AWD

AWD cars generally (always?) allow only a very limited variation in tread depth from tyre to tyre.  Driving very far with one tyre with a much different tread wear or tyre size will damage some very expensive drive parts.

#6

Thanks for the info everyone. I actually already took that tire off. I had a full size spare. I will be getting new tires next month and will make sure to check on the balancing and alignment. If anyone thinks of any other reasons there would be three very worn down spots that would be great.


#7

Please read your owner’s manual: does it warn against using a new tire with 3 worn tires? It could cause problems with your awd system, as JEM says above.

Those 3 worn spots were caused by either a worn/damaged strut, a worn/damaged other suspension part, a severely out of balance tire, or (pretty unlikely) a bad alignment. Probably a combination of 2 or more of these problems. The sooner you get it checked and fixed, the better.


#8

Is there an easy way to figure out what part is worn,damaged and is the strut or other suspension parts fixable at home. I don’t have a lot of mechanical experience but I had done some bigger jobs like change the timing belt. Any info would be greatly appreciated.


#9

To check the strut, do a ‘bounce test’ at each corner of the car (push down hard at each corner, observe how the car bounces before it comes to rest). If one strut is bad, that corner may bounce longer than the others, but it’s not a fool-proof test. How old (years/miles) are the struts?

As for damage an alingment, you’re better off taking it to a shop for this. If you don’t have one you trust use the mechanic finder under ‘actual car info’ on this site.


#10

Another vote for mis-alignment.


#11

So I took my car in and got some new tires and the wheels balanced. Brought it to the Audi shop to check the alignment and suspension. They let me know the rear right tire camber and toe was off slightly. They put the alignment back to spec and said it was probably a mix of that being off and having the car weighted down with 4 people and tons of stuff for 10,000 miles straight but they couldn’t find anything else. If anyone can think of anything else I should check let me know. Thanks


#12

It sounds like you did all the right steps. Sometimes one tire can look much more worn than the others through a combination of minor misalignment and having the other tires almost worn out. There’s not much difference between a little tread and no tread.

Keep an eye on them, and rotate them consistently.