Noise from underneath....
JK Newbie
Joined: May 2008
Posts: 33
Likes: 0
From: Coto de Caza, CA
Vibration noise
Today I crawled under my 07 unlimited and found 4 loose bolts on both the exhaust flanges where the exhaust pipes come up and meet the exhaust manifolds. Not easy but tightened them, no more vibration type noises on startup. Craig
JK Freak
Joined: Jan 2009
Posts: 593
Likes: 0
From: Los Angeles, CA-All Day!!!
i had a very similar issue w/ my JK, i turned out to be a broken tack weld on the heat shield nearest to the catalyc conveter/s. i took into the dealership a couple of weeks ago & htey fixed the issue at no co$t. 
JK Freak
Joined: Feb 2008
Posts: 513
Likes: 0
From: delaware (north)
are you sure you diddnt just scoop up some pebbles with your skid plate.
the tcase skid plate is very good at holding mud and rocks cause of its high walls.
and since you said it happened after draging it than that would be the opprotunity to catch a few
the tcase skid plate is very good at holding mud and rocks cause of its high walls.
and since you said it happened after draging it than that would be the opprotunity to catch a few
JK Enthusiast
Joined: Jul 2009
Posts: 435
Likes: 0
From: NJ
Check the welds on the crossover exhaust pipe heat shield , one little broke weld makes it sound like you got tranny probs when you gas it. On mine one broke , I pryed it away with a screwdriver, no more noise. A month later, same thing, next weld. Check also the u-bolts that clamp your exhaust together.