Ok, so my jeep as long as i have had it has a slight little clank clank clank,it go's away when i give it some thottle so i haven't worried to much about it. And with the way i treat it it hasn't gotten any worse! what I'm wondering is , it doesn't knock at all when i first start it up , sounds perfectly normal till it warms up then i have a little clank! iv heard before that a cracked exhaust manifold can sound like a knock. I'm at school now and i kinda looked at it and i coudn't see any cracks. just figured id see if any ones els's did something like this.

 

Mine rattles a bit too, have you checked the hangars securing the exhaust line to the underside? That can cause a mean rattle haha

 

yeah, i have checked those, my flex plate bolts were loose, that helped it out alot.. but the thing that stumps me is , it does not knock at all for maybe the first 5-6 mins when i start it up! an then go's away when i ive it jut a bit of throttle. so thats why i figured maybe exhaust mani!

 

How's your idle? Does your oil pressure drop after it idles a bit? If you have a low or uneven idle it could rattle, everything might haha. Mine rattles like a hoe after a few minutes stopped at a light

 

she idle's great ,oil pressure stays at 40 at running temp! she runs strong.

 

Cracked manifolds are pretty common. Easy to tell if you have one if you can hear the exhaust leak but can be hard to notice if its always been like that. Is your engine pretty loud inside the jeep and underneath?

Oh you have an 01, didnt think those had the same problem hmmm

 

I have an 01 too, thought they fixed that on 00-01

 

Could be the exhaust gasket where the header meets the downtube, Those are pretty common on all cars

 

i have a 91. dont know where ya'll got that i have an 01! and no it ain't terribly loud. it sounds about like my other jeeps.

 

Oops, thought the other person was the poster and mixed up years

 

Wish I had a 91 haha

 

Doesn't an exhaust leak usually only show its face when its cold and when it heats up it goes away because of everything expanding?