1999 Jeep Cherokee Classic - V6 - ~180,000 miles

Took 99 Jeep to shop to get new tires, oil change, etc...

Shop indicates the exhaust manifold is cracked and needs replaced.
Is this(manifold) a common problem for a 99 Cherokee ?

Any TSB out there ?

Thanks for info !

 

Cracked exhaust manifolds are a very common problem. The stock design is pretty efficient, but they are terribly prone to crack. It is not a question of if it will crack, but rather when.

Replace it with a header. There are plenty of available headers out there. Some of the cheap-o's use a very thin flange where it attaches to the head. I'm not saying all inexpensive headers are junk, just be careful when you shop. IMO, you usually get what you pay for.

 

That or take stock one down an weld the seems like I did an then add a small flex section in the spipe that should keep it from cracking again.

 

A weld job is plenty cheap and will solve the problem for quite a few years. I have to do mine but my brother has a new header that he wont' use so I'm buying that. I'd rather just weld mine but gotta help family out you know.

BTW you have an I6 not a V6 unless it's a really special jeep

 

Sorry if this is a derail but how much of a pita is it to remove?

 

mine was cracked also, right where all the pipes merge to the collector. I took it off and a friend welded it for me. Problem solved , only thing is it will take quite a few hours to do since you have to take the intake manifold off first. Also make sure all the bolts are tight once you put it back together , if the intake manifold is not tight enough it will suck air and will run like crap.

 

it took me about 7 hours to do but 2 hours of it was getting a new gasket at the parts store and taking the exhaust manifold to my friends house . he had to set up his welder and do the work.

 

Exhaust/intake manifolds took about 3 hours. Get a short flex-handled 3/8 drive rachet. Best investment I've made so far, and fits many places others won't.

 

As they all said. I think this is the jeep 4.0s most common problem. It's rediculous. They build a bullit proof motor and then just keep putting this junk manifold back on it time after time. No redesign lol. Completely asanine!

 

Thanx y'all I think ill pull mine this weekend and weld it up. Anyone know what type of metal it is so I know what rods to pick up. My break is right where the two pipes come together at the bottom.

 

just jb weld it back. lol, sadly seen that work

 

Too much flex and vibration, jb weld or Mega stick would crack and pop off. If its cast it will be a pita,anything else will be no problem for my one ten welder .

 

Just weld it.
If you are good and using a wire feed welder you can probably do it in the jeep. I have done a few times. Removing it will make it easier though.

Make shure all the bolts are tight. sometimes the back ones loosen up and cause a leak.

Do not use JB weld or any other type of epoxy, sadly I have seen that catch fire! Header gets real hot!

 

i have never seen it on fire. and ive seen it used on some very high temp applications...

 

I've tried Mega therm( high temp jb type **** ) after a few bumps it cracks off. I'm going to stick weld it I don't think it's cast down by where the two pipes come together. Don't know what metal it is by I'm going to hit it with some 7018 rod.