Tell me why not to do this...

Just went and got my new 96 Cherokee. Wow, this thing is in amazing shape. It was a fire truck support vehicle and they REALLY took care of it. When I am done washing it, will be about brand new. (thanks for help from others on what tools to bring, thankfully I needed none).

However, they said the headers had a small crack in it, and I knew this going in. When I looked at it, it is barely noticeable and Im wondering if I could weld it in place. I ask this as I assume if I take it off it may distort during the weld and may not go back in correctly and / or not seal correctly. So in essence I would be using the block as the jig. Cant get in to get a good pick or I would post it, and may do later if start yanking everything surrounding it.

Sure I would remove most things in the way and use a weld / fire blanket. But anyone have any input on why not to do this? I dont care if ya flame the noob cuz it is 1:30 in the am and I just drove 10 hours to pick it up, so get a bic if this is the dumbest question ever and Ill pour the gas. But I had a ton of time driving home and cant come up with a reason, so tell my why im an idiot. The weld would be about a 30 second weld tops.

Also, anyone know how to remove vinyl stickers? They are 10 years baked on in AZ sun and I had a hell of a time removing about an inch.

Will try to post pics tomorrow.

I assume you're talking about the ever so popular cracked exhaust manifold where the pipes meet at the collector. If that is where the crack is then take the whole thing off and lay it on a bench as it won't distort or move when welding. Even if you're talking about a crack in the manifold by the mounting plate the pipes still won't move. One thing I would recommend doing if you're going to fix the crack is get an expandable exhaust piece and put it in the exhaust system in front of the cat, doing this gives the exhaust a little flex to prevent new cracks from forming.

As for the stickers, a heat gun works great if they are not to dried out.

to help prevent the crack from growing later, drill a hole at each end of the crack, and yes, add a flex coupler

The manifold needs to be removed to weld it. Welding them seldom solves the problem, they just crack again. If you spend the time and effort to remove the manifold, you might as well replace it with a better part. The APN manifold (http://www.ineedparts.com/auto-parts/exhaust-parts/exhaust-manifolds/jeep-exhaust-manifold.html) is a quality part that fits perfectly. Use the Search function, many members have installed the APN and there have been few, if any, problems with it.

All good advice, thank you all. Hate to weld it, go thru all that then have it crack again. What a shame to drop several hundred on something like this when I spent so little on it in the first place. Maybe I will just leave it and tell everyone its a diesel conversion:banghead:

Heat gun didnt make a dent. This stuff has baked for 13 years at 110 degrees every summer

Yeah, my MJ spent its first 16 years in Las Vegas. It was a real pain to get the stickers and residue off. I got most of it, but there is still some hardened adhesive that is as hard as rock. I'll have to use a sander on it if I ever get around to painting the truck.

3M Stripe Off Wheel, big eraser that goes on a drill



Another option is saturate the stickers with WD40 and let it set for a while. It will eventually break up the adhesive and you can use a SOFT wire brush attachment to get the bulk off.

X2 on the 3M rubber wheel. They work quite well. You can then clean up any remaining adhesive with some Goo-Gone.

Tim_MN said:

The manifold needs to be removed to weld it. Welding them seldom solves the problem, they just crack again. If you spend the time and effort to remove the manifold, you might as well replace it with a better part. The APN manifold (http://www.ineedparts.com/auto-parts/exhaust-parts/exhaust-manifolds/jeep-exhaust-manifold.html) is a quality part that fits perfectly. Use the Search function, many members have installed the APN and there have been few, if any, problems with it.

Click to expand...

x2. Good advice here. I installed the APN headers in either '02 or '03 and have put around 50k on them with no problem.

Stock style headers can be had for under $100. The cracked one lasted 13 years, what more do you want? By the way you WONT get enough added performace from aftermarket header to be worth the added cost

This is why I love this site. I have never in my life seen that "eraser" before. Should have sat back and drank beer and waited for a response. Instead I went with plastic scrapers, goo gone, wd40, kitchen soap, simple green, bug remover and power washer.... repeat all that 3 times and I am 99% done. Wow, what a pain!!!

Stock headers under $100? Assuming on ebay? Will look around... Thanks guys / gals.

$100 or less is Ebay, Rockauto is $180-200 and quadratec $150 plus

X3 on the APN, definitely worth it. Installed mine last year and its great.

Have a good look at your motor and trans mounts as well- worn mounts are allegedly the cause of the cracking manifolds. They're not hard to replace even with the manis in place, but it would likely be even easier when you've got it all torn down.

After griping to a friend of mine he came over with this http://www.amazon.com/Meguiars-M0216-Mirror-Fine-Cut-Cleaner/dp/B0002SQVDK then laughed at me because it took him about 10 minutes to remove what had taken me days. So I wanted to make sure and give back to you guys. My paint looks braaaaaaannnnnnnndddddddd new where we used this and it took off all residue, glue, marks etc. The stuff is magic in a bottle. Next time I will definately try the wheel eraser to get off the top coat and this for the final stage... actually there wont be a next time.

Also, took a good look at the header crack. It is right at the bottom where one goes two into one and if I took off the airbox I think i can get right too it. Dont think will be a pretty weld, but dont care about that. My buddy said, dont ya think the heat will be bad? I dont think so as I will do like 5 second welds and give plenty of time between with stitch welding. My wife and friends think im crazy,,, I frankly dont see the issue. And why not as if it doesnt work, Im replacing it anyways right?

might have room to weld, BUT do you have room to clean the area up first for best weld?

grind/wirewheel/sand it to make it rust-free, paint-free to make the weld much better, less chance to crack again.

however you can try that first and if it crack again, get new headers, you wont be lost much time and $ that way because no need to remvoe lot stuff and new gasket, etc

I welded my stock header once just around the crack and it cracked again not long after. The second time I welded in between the tubes all the way up until they split away from each other and have had no issues since. It takes a long time and some patience but welding it so far up the tubes stabilizes the tubes to reduce high frequency vibrations that can induce cracks. Also the extra metal acts as a heat sink of sorts to eliminate localized hot spots that can lead to cracks.

A local shop welded the exhaust header on my Chevy Astro Van and it did fine. But IIRC they had to use special techniques since it was a stainless steel header. Something about heating the steel with a torch before welding.

As for your sticky situation try a product called GOOGONE I find it works well.