I hear a noise coming from the underside of the truck when I am travelling 65mph and higher. It sounds like when you blow over an empty bottle. The best way to describe it is a deep "toot". It happens only when I take my foot off the gas and at 65mph and greater. I have just over 800 miles on this 2003 truck and am looking for anyone who may know what this is. Thank you.

 

gray matter:

Check out the "humming" post and replies below. This "toot" sound may be the rear end, as described in that post.

 

I called the dealer and of course he couldn't tell me exactly without driving the vehicle, but he said it sounds like it is a pinion noise. I will have to take it by so he can drive the truck and hear it for himself. It seems like this is different in that, all of the other posts describe the noise while the vehicle is accelerating. My noise is noticable only when I take my foot off the accelerator. I guess I will find out when the service tech takes it out. Thanks for the reply Rileyrott.