I have a 2020 Ascent Touring model – love the car and the way it drives. I put new tires on them (Bridgestone Alenza AS Ultra) at about 40K miles, then rotated them at about 45K. Shortly after revving, I began to notice a subtle knocking noise/vibration at about 30 mph. I first noticed it on a patch of fresh pavement in the city, then I just heard and felt it, I hear/feel it every time I go anywhere. I would describe it as a subtle tapping noise (hhrrrmmmm, hhrrrmmm, hhrrrmmmm) with a periodicity of approximately 2-3 seconds at 30-35 mph and an even more subtle vibration that I can feel through the pedals and steering wheel. I’m pretty sure it’s coming from the front, and I suspect it’s the right front, but I can’t say for sure. It varies with speed and is more noticeable on left turns. I took it to the shop where I bought the tires and got one of the mechanics to go for a walk with me – he immediately listened to it, noted the speed at which it started, and so we drove around for about 10-15 minutes at various speeds, turns, stop/start, etc. I left it with them for the day but they were unable to identify the source. They checked the tires, all balanced, rotated the tires back to original position, but the vibration/noise is still there, so it doesn’t seem to be a tire thing. They didn’t find anything loose, everything is tight and in the pepper, so they suspect a bad bearing, but don’t know where/which one. That was 2 weeks ago and since then I’ve put about 3000 miles on the car (all highway, 2/3 of it with a trailer) and everything is the same – no changes, no ill effects on driveability or gas mileage ( except with trailer). There doesn’t seem to be any risk of a sudden failure, but I had hoped that the condition might get a little worse with all that running to help isolate the cause. Any ideas?
