first off i'm not a mechanic.

there has been a light knocking noise under the steering wheel coming through the floor. i can hear it when i'm running or idling. it sounds like something is knocking on the body...not very audible unless you're in the drivers seat and you can feel it in your feet. i've had the 2000 1500 5.9 for 2 months and it just started making the noise a couple of weeks ago.

i looked under there just now and noticed that there's about a 3/4 inch separation from the exhaust manifold flange/or the diamond shaped fitting and the flange of the exhaust pipe. i can see a pipe in between these that is not corroded, whereas the pipes and fitting are corroded red. is this how it's supposed to be or could those bolts have come loose. could this be the knocking?

thanks,
jenny

 

im assuming 1 or more of the 3 bolts that hold that flange together are shot and gone. with that im assuming that sound your hearing is the flange rattleing around from it not being bolted

 

Check the bolts make sure there tight, that might just be how it is.
Start the truck and then get down on the ground under the truck and listen to see if its coming from their, you can use a machanics stethoscope or a short piece of hose to pinpoint location of noise
Sounds like their is an exhaust leak though so start just below header and come back

 

There are only 2 bolts that hold the flanges together