exhaust manifold?

ok well ive had my jeep for about 2 years now and when i bought it it had an exhaust leak... later i found out it was the exhaust manifold...its cracked so i get that dumb cracking noise when it runs... i mean ive had my jeep for 2 years and i drive it every day ... and it still has the cracked exhaust manifold, i would like to know how hard it is to replace this... i know i could get a used exhaust manifold on here for pretty cheap but i just wanna know how hard it is to replace it? thanks

Heh, just did this yesterday.

Wasn't as bad as I thought...somewhere between 'bitch' and 'tedious'. Took *me* just over 2 hours start to finish, but I've known others to take 4 hours or more. Just depends on your skill level and how badly you want to get it done. There are bolts on the underside of the intake manifold holding both pieces (in/out) together, so a ratchet and extensions with universal swivels help greatly. Open ended wrench for the top works best, I've found. The bolts are only at like 30 to 35lbs-ft so they're not hard to break loose or put back in.

IMHO spend some $$ and get a good stainless header instead of just replacing with another stock manifold. They will all break eventually.

Put a Gibson stainless in yesterday. Sure is a lot quieter now!!!

Found at this weekend that mine is cracked, too.

I haven't looked too closely at what it's going to take to do the swap. Is all the work done from the top, so you have to remove the intake manifold, or can it be done from underneath w/o removing the intake manifold?

You'll find yourself popping above and below the Jeep to get it done. The intake and exhaust share bolts, so they're both going to have to come off. Depending on the year, you may have to remove the power steering pump and prop it out of the way. Remove the airbox as well and pull it all apart...

ECKSJAY has a can of PB Blaster in the foreground and you're going to need it. Get some CopperKote spray as well and coat both sides of the new gasket before installing it.

Yucca-Man said:

ECKSJAY has a can of PB Blaster in the foreground and you're going to need it. Get some CopperKote spray as well and coat both sides of the new gasket before installing it.

Click to expand...

I did all work from above...with exception to the downpipe bolts which came off first and the motor mount bolts. Motor mount did not need to come off, I just happened to notice that mine was toasted (literally, dry and hard) and cracked so I replaced it. Removed air box and steering pump, then took off the fuel lines from the rail, and all vacuum lines to the intake manifold. Used a ratchet strap to hold up the intake, then removed the exhaust manifold.

The PB wasn't necessary for mine, but sure made life a LOT easier. NONE of the lower bolts were done from below. My long fingers probably helped in removal and installation of all the bolts. All I did was break them loose with the wrench, then removed them with my fingers. Just wasn't any friction holding them in. Going back in was the same story, finger tight and torqued down with a wrench. Didn't use any copper coating (even though I had it on hand) based on firsthand shop experience with the Gibson gaskets, but it will never hurt to use it.

Hmm...good to know that it's mostly possible to do from above; probably depends on your height and that of the Jeep as well. I foundd it easier to get underneath and get a few of the bolts out that way, including the downpipe connection.

I was replacing fuel injectors at the same time so my intake came completely off before getting cleaned and thoroughly rinsed out. We actually used some smelly Valvoline Synthetic stuff that worked wonders to loosen the bolts and penetrate threads.

As for replacement options, there's Borla, Gibson and Banks. Mine was a 99 exhaust that had been ceramic-coated and never installed by the previous owner.

will one off a 95 fit on my 99?

I am in the middle of replaceing my manilfold, at 200,000. It is completely split at the collector.
Anyways, I was pulling all the lines and cables and labelling them, I am using a Haynes Manual (YUCK!). The descriptions they have are horrible and the pictures are so close up that its hard to tell where they are talking about. So I just started unhooking and labeling things as they made sense to me. So far so good.
Are there any precautions to know before hooking everything back up? The things I awas wondering about was air geting into the the feul line or something?? Dont' know if thats even a problem or not. This is the most technical thing I have undertaken.
Also I am replacing my down pipe. I noticed the end that connects to the header is at a different angle than the stock one (although my replacement pipe is from a donor XJ).....I hope it doesn't give me problems when installing it. My new exhaust manifold is off the internet, is stainless and has the expansion chambers...seemed to be the best quality for the price... $95

Anyhow, I would gladly recieve anyones suggestions or criticism.
-Rob

the only aftermarket header replacement I would consider is the mopar one. To many horror stories about other cracking, not fitting or sealing. Banks seems good as Borla but the don't have one for my 89. Either that or I'm gonna make my own. Saw a guys this weekend the made his, seemed to work fine.

He took a 2-3" piece of exhaust tubing for the collector, then ran tube sections formed to the ports shape straight into the tube. The tube runs pretty much straight back then bends down to connect to the exhaust pipe. probably not the perfect flow but it seems to work fine.

When I replace the motor in Ali's XJ last month The header was cracked in several places

I pulled it off and carefully ground down the cracks and mig welded them and ground down again, used water to check for any leaks. Then I used several small 1/8" x 1/2" metal straps welded to the tubes to support the poor design and welded the 2 down tubes together, I did this on my 88 too and it never had any issues again.