Strange behavior in my AWD 2006 sienna with 165k miles. Noticed a front end shimmy that was intermittent, not while braking, figured it was a tire. replaced all 4 tires with new and had alignment done by a good shop. Still have the problem, but I have noticed that it only happens after the vehicle is stopped. So when I first start, it drives fine until about 50-60 mph when I notice a shimmy in the steering wheel. It varies in intensity, sometimes mild, sometimes pretty significant. It doesn't seem to pull to either side. Also, I can hear a slight roaring type sound when this is happening. If I drive for about 5 minutes it will improve slowly and then go away, shimmy and roar both, and it will drive like a dream. No pulling, no shimmy. If I stop the vehicle at a stop light or something and go again, I get the same problem.
So I conclude that it would not be tires, alignment, steering rack, shocks, bearings, because those wouldn't improve after driving a few minutes. It's got to be the brakes, right? But the rotors are fairly new, and I don't get a lot of pulsing while I am braking. Maybe a stuck caliper? But why wouldn't it pull to one side? I should mention that the check engine and VSC lights are on, but I think they are from an oxygen sensor which has never been replaced. I don't suppose the VSC system could be causing the shimmy through a malfunction, could it?
So I conclude that it would not be tires, alignment, steering rack, shocks, bearings, because those wouldn't improve after driving a few minutes. It's got to be the brakes, right? But the rotors are fairly new, and I don't get a lot of pulsing while I am braking. Maybe a stuck caliper? But why wouldn't it pull to one side? I should mention that the check engine and VSC lights are on, but I think they are from an oxygen sensor which has never been replaced. I don't suppose the VSC system could be causing the shimmy through a malfunction, could it?
