I dont know if it is specific to my truck, but I randomly hear what sounds like a clunk noise under the bed of the truck. It only happens when i first start the engine and it does not happen everytime. Has anyone else heard this. It is not terribly loud, and it happens as soon as the truck begins to idle. Tranny? Gas tank? what could it be?

thanks in advance.

 

23 hits an no replies.................wow, nobody has anything?

 

Could it be your cat. conv.????
Hit it with a rubber mallot or whatever & see if it makes the noise

 

This same sound on my truck turned out to be the yoke joining the drive shaft to the trans. They had to replace the whole drive shaft.

Try stompin' on it from a dead stop. If you hear the clunk just a second or two after you start movin, you may have the problem I had. I had to take my truck to three differnent guy to figure it out.

Good luck.