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Thumping noise in front weel/axel...only when cold

This winter, my car has started making a noise that sounds like there’s a leather strap on the wheel hitting the firewall. I can hear it inside and outside of the car. It only happens when it is cold (for North Carolina, not North Dakota) and after a few miles the noise stops but is there the next day without fail. There’s no change in sound if I let the car idle first to warm up. The colder it is in the mornings, the sound is longer lasting. It definitely changes frequency and volume (louder) directly with the speed. I can kill the engine and coast (safely) and the noise is still there. It doesn’t go away when I hit the brakes or turn in any direction. I just had the tires rotated and balanced (I assume that the shop would see it if the wheel bearing is loose). I can’t replicate the issue for the repair shop because it’s warmed up by the time i get there…and leaving it overnite is problematic having only the one car.

Many performance tires use a nylon “cap ply” between the tread and the steel belts to get a better bond between the rubber and the steel. Nylon cord can and will take an overnight “set” and thump for a few blocks. Look at your tires and see if there is a nylon ply in there…

Thank you! How can I tell if the cap ply is at fault? The next question would be what to do? is this a defect (the tires are still under warranty) or something I can ignore?

No defect. It’s normal for Nylon cord tires to “take a set” overnight…Back in the old days, when many tires were 4-ply Nylon, they would act like they were square for a couple of miles. Tire manufacturers switched to polyester which does not take a set. But for pure strength and BONDING, nothing beats nylon. So they have gone back to it to prevent high-speed tread separation. The construction materials will be molded into your tires sidewalls.

Thank you VERY VERY Much!

I won’t tell you not to check out the tires as Caddyman suggests and he very well may be right.

I’d also just mention that it wouldn’t hurt to have a front end shop give the CV joints & wheel bearings a once over. The reason being that one of the things that happens in the cold is that grease gets harder and doesn’t lubricate as well. If you, e.g. had a wheel bearing seal or CV boot blow you will have lost some grease. Until everything gets warmed up enough part of the bearing/joint will lack lubrication. It can also just be worn parts + cold grease = some noise.