Hi all,
The Prius is 2nd gen (2009) with 67K on it now.
I have this noise I'm having a hard time explaining to the mechanics at the dealership, perhaps because it has started right after the latest service when they rotated the tires and replaced the oil in the front differential.
I can describe it as a rather soft knocking sound that seems to be coming from the passenger side from wheel, with the frequency of once per revolution (or twice - it turned out to be very hard to drive, count and look at the passenger side wheel at the same time :) - need a huge mirror for that!) . Well, it starts soft but becomes harder and I can even feel it of the steering wheel after long and highway speed drives.
I brought it down to the dealership and they claim they could not find or hear anything but the tire and the wheel look OK (tires almost brand new - about 5K on this set yet, balanced before first installed), brake pads and the disk look fine and no foreign objects. So, they said, it's safe to drive and don't worry too much.
My wish for this noise to go away didn't materialize and I think it's getting worse. So, I decided to ask for suggestions in this esteemed group before bringing it to the dealership again. What do you guys think it can be? If not the wheel/brakes, could there be something in the suspension that can make such noise? The timing it started is very suspicious - could they have screwed something up in the front differential while changing the oil there? Else could they have bumped the wheel against something while rotating the tires?
Any suggestion and comment you can offer will be most welcomed!