Been driving a new 2007 Altima for 3 months now and there has been a noise from day one. While at idle there is a thump that sounds like someone flipped my front fender with their finger. I can feel it through the automatic shift lever. It does it in gear, out of gear, a/c on or off, about every 15-20 seconds.The dealer said it was the exhaust pinging from temperature change. Now for the wierd part. The car sat overnight and when I was walking out to get in the next morning, it thumped all by itself. It seemed to be coming from up front. Has anyone experience anything similar? Thanks

If your literally feeling this noise on the shifter I'd have to say that this is definitely not a exhaust ping or none that I've ever heard. I'd go for a second opinion, sounds like the dealer is being lazy to find the real source of the sound.

I dont know about it happening repeatedly over a single driving session, but one thump that you are hearing is from the ABS testing itself. If you look in the manual it talks about it.

But it should only happen once when you first start driving the car. I think you have to get up to a certain speed like 5-10mph, I don't remember.