Low booming

[shrtbx]

Im starting to hear a low booming sound coming from the engine while at idle. Sort of sounds a low thunder sound from far away or like someone beating on an oil drum. I can only hear it at idle and it shakes the truck until i take off. If i throw it in neutral while at a stop and step on the gas it goes away. As tank gets lower the shaking gets worse. Any ideas guys on what might be going on?

[xtreme80]

I think the gas tank think might be in your head, but I could be wrong. Check the flex plate bolts and make sure those are tight. Can you pinpoint where it's coming from? Have someone hold the truck in gear and listed under the hood and underneath and let us know what you come up with.

[shrtbx]

I think you are right about the gas tank. I was was listening to the exhaust (which comes out before my rear tire on the drivers side)on the way in to work and noticed that i didnt hear any sort of missing sounds or hesitation coming from it at the stop light. But at the same time i heard that low booming sound wich was not that bad today but still there. So that tells me its something external. Im going to take a look at the flexplate tonight if i have time like you suggested.