2008 Lucerne. From the time I bought it, it had a shudder in the driver’s side front end when the brakes were applied. Dealer did a brake job at 10K replacing pads, turning rotors. Now, I have a rattle in the front end that sounds like a heavy thump. Dealer replaced intermediate steering shaft at 12K, but noise still there. The colder the car, the worse the thump. As you drive, it fades, but is still there as a faint thump. In 13 degree weather on Friday, as I started and pulled out, each rotation of the driver’s front tire produced a heavy thump. As car warmed up, thump faded. Could it be a warped rotor or bad bearings from the brake job.
If the noise existed before and after a brake job, then it’s probably not the brakes.
Many shops (especially chain shops) will do a front-end check for free, time to look for something else like a swaybar link or loose strut or who knows.