I could not start a new topic and I apologize if this is not the same problem as described in the TSB.
We own a 2006 Lexus GX740, and when the speed gets above 65 mph on colder days (we are in Phoenix, so this constitutes about 55 to 65 degF), we hear a banging or thumping or flapping noise underneath the car on the right hand side. We are having a tough time figuring out if it is in the front or the back of the car.
This happened within the first week after we owned the car. It is intermittant, and the dealer has not been able to reproduce it, either because it heats up or they do not drive it around enough. We have brought it in four times.
When it does start occurring, it will make this thumping, banging or flapping noise for hundreds of miles - it almost sounds like rocks in the wheel well, someone hammering on the bottom of the car, or a mid-pitch thumping noise. Everyone that hears it is a bit shocked, thinking the tire has gone flat. My wife tried to explain it to me for the last year and for the first time, I heard it as we drove to our relatives house about 300 miles away and it was so loud, I was concerned something would break.
When she has had friends in the car, they were concerned that the tire went flat. When we inspect underneath the car, everything looks fine.
This happens with no turning, no bumps, no wind, just driving down a smooth freeway on a perfectly still day.
