Exhaust manifold crack??

[joe_gold]

So while doing the whole seafoam smoke show on my '90 xj I noticed quite a bbit of smoke coming from the exhaust manifold area.
:smsoap:

My assumption is that its cracked because of all of the posts I have read on here. After looking in the Hayes book and realizing that I need to take everything with the intake and exhaust apart because of the gasket/engine design my question is what would happen if I didnt fix it?
:flame: ???
I just quit smoking a few days back so I dont think I have the patience to deal with that big of an operation without a really big hammer in which case more than just the manifold will be broken.

Thanks

joe

 

[Muad'Dib]

Its really not that hard if you remove it along with the intake manifold as a unit still bolted onto the head, and just pull the head. The only problem with that is getting it back on. You will need a hoist, or a very good helper.

If you dont fix the problem you will get poor gas mileage (like the xj could do any worse) and probably wont pass emissions (if applicable). Worst case scenario you could have a engine fire because the Injectors on your RENIX or so prone to leaking.

You may want to pull out a mirror (or buy one they are cheap) to inspect the manifold. Cracks usually are pretty noticable. Also tighten the bolts for the intake and exhaust manifold as they DO come loose causing some serious exhaust leaks also.

 

[Newbie94XJ]

well there has always been a warping and cracking problem with the stock cast iron header. they would get hot and touch water and instantly crack. i never thought it would happen to me BUT it has i have found some high flow stailess headers on ebay for abou $187 or so that i wanna get for my 94 XJ. so good luck with your exhaust manifold

 

[desertracer]

well there has always been a warping and cracking problem with the stock cast iron header. they would get hot and touch water and instantly crack. i never thought it would happen to me BUT it has i have found some high flow stailess headers on ebay for abou $187 or so that i wanna get for my 94 XJ. so good luck with your exhaust manifold

Uhh my OEM exhaust manifold was steel, not cast. I think the only ones that are cast are the late model 4.0, like 2000 or 2001, and those are the only ones that DO NOT have cracking problems. I could be wrong.

When mine cracked I got a Doug Thorley header and it cracked pretty quickly.Then I got a cheap one off eBay for under $100 and its held up well so far.

 

[joe_gold]

As for pulling the whole head I think that is a huge can of worms that I am sure will wind up with me pulling the whole motor to reseal the whole thing which would be time to rebuild since it would be out and the rest of the slippery slope saga begins.

I think stock will be the way to go if I do have to replace the exhaust manifold since every time I've used aftermarket headers in my trucks the heat has caused more issues than the HP gains were worth.

hopefully it is just loose.. :wow:

 

[Deadman 94 xj]

Just fix it and be done with it. Stock manifolds are all prone to cracking because of bad design if nothing else. It's pretty easy to tell if it's cracked, especially if it's enough to blow the seafoam out like you said. You should hear a good amount of "ticking" from the engine compartment.
The job really is not that bad. Just be patient with locating and removing the 11 bolts. 5 on top, 4 underneath, and 2 on each end. A good wratcheting wrench will be your friend and a couple of socket extentions. You can pull the intake manifold without removing the fuel rail.
I replaced mine with the APN header. Do a search and you'll find good reviews for the quality and price.

 

[4.SLOW]

I just had this done yesterday out here in Santee. Just buy the APN.

http://www.automotivepartsnetwork.com/store/pc/viewPrd.asp?idcategory=&idproduct=20009

I didn’t have time to do it my self I have my own machine shop to run and tons of work so had the mechanic guys
Next door that are slow rite now do the swap for me they replaced the manifold installed my new injectors and cleaned the throttle body.
It took him about 3 hours to do the job cost me $300 but I made more in the same amount of time.
A little pricey but you only have curse &%*((&&* one time………….when you pay the man.

PM me for more info.

 

[dubbyx]

The APN one won't work on a '90 from what the APN site says (Bold letters even). I've been dealing with a similar issue on the junk wheeler I've got here. I havn't found a good suggestion as to where to get a better one for this model though. I'll most likely pull mine and weld it back up, but for now I've just got aluminum tape sealing the crack so I can find all the other issues before I pull it.

 

[4.SLOW]

my bad..........:hang:

 

[ReftonsRed]

So while doing the whole seafoam smoke show on my '90 xj I noticed quite a bbit of smoke coming from the exhaust manifold area.
:smsoap:

My assumption is that its cracked because of all of the posts I have read on here. After looking in the Hayes book and realizing that I need to take everything with the intake and exhaust apart because of the gasket/engine design my question is what would happen if I didnt fix it?
:flame: ???
I just quit smoking a few days back so I dont think I have the patience to deal with that big of an operation without a really big hammer in which case more than just the manifold will be broken.

Thanks

joe

I did mine maybe two days before inspection so it would pass. Its not a real tough job either 3-4 hours max. I picked up a header for around $120 @ aoutopartswearhouse.com and is been good to me

 

[Throttle]

that APN header doesn't look all that efficient... did anyone notice any gains from going to this manifold?

 

[Muad'Dib]

that APN header doesn't look all that efficient... did anyone notice any gains from going to this manifold?

Some say its basically a BANKS knockoff (looks / acts like a banks).

This thread will help.

http://www.naxja.org/forum/showthread.php?t=73552

 

[joe_gold]

Yeah I noticed that year wont work. they have another in the $200 range. I am going to try to find the crack this weekend and maybe try a band aid fix with some epoxy putty and tape. Kind of a liberty bell theory.:laugh2:

I wont have time for much more than that for a few weeks.