Exhaust maniford replacement...

Currently have a cracked exhaust manifold and looking for a replacement. Just wondering if anyone has used the Dorman OE replacement. Has a lifetime warrentee and from what I read almost alll of them crack over time so looking for any feed back. I am not looking to spend $500-600 for a header. Below is a link the manifold I am talking about...

http://www.partsamerica.com/ProductDetail.aspx?MfrCode=DOR&MfrPartNumber=674170&PartType=1359&PTSet=A

i assume its for the 90 XJ listed in your signature? there is a company that makes manifolds with expansion joints in them and sells them at excellent prices but all ive used is stuff for HOs from them. i dont see a Renix header listed but they may have them. check this Ebay search.

http://search.ebay.com/search/searc...satitle=jeep+4.0l+exhaust+manifold&category0=

Ok well i will let you in on what I found out when buying a preplacement for my renix...... only ones who make a "replacement" are the Chimos. Quality sucks, flanges are not flat and tubing is quite thin like the stock ones. The ebay ones are ( i belive) the same ones at schucks and what not, all the same. Right now after swapping 3 gaskets on new engine I had it machined down flat and will try that now. If doesnt work may buy the turd Pacesetter header and modify it with a "B" flange collector, for about 300 bucks and try my luck with that, if that dont work I will be pulling off the head and converting to HO to be able to have a bigger aftermarket range to choose from. Great things to deal with on a built rebuild with 2700 miles

Not what I was wanting to hear, however good to know. Anyone having success with a Renix and aftermarket exhaust manifold?

So no one has had success with the replacing a Renix exhaust manifold with out it recracking?

Josh, I'd recommend adding a section of flex pipe into the exhaust when you replace the manifold. There's no "give" through the entire exhaust run, and I'm positive that helps lead to the stress cracking we see around the manifold. Hell, my frakkin' minivan even has a flex-pipe section in it...why AMC/Jeep/Chrysler never figured that out is beyond me.

Jim www.yuccaman.com

I did. Make sure you use some hi temp sealant on the gasket. I also filed the flange to remove any high spots, and scraped and scotch-brite'd the head. if you haven't recently done so, I consider changing the CTS and the engine mount while it's all apart.

This is the one I ordered.

http://www.autopartswarehouse.com/d...entQQExhaust_ManifoldQQ19871990QQJ960707.html

So far so good on my 89 with the Dorman brand OEM replacement. I did put in a flex joint right befor the cat though also. It is out there to help cut down on the flexxing of the exhaust as the motor torques. hers the link..
http://www.naxja.org/forum/showthread.php?t=958060&highlight=flex
and another thread I posted on
http://www.naxja.org/forum/showthread.php?t=954891&highlight=flex

Hi All,
i try the search an found this Thread. currently i'm looking for a new exhaust maniford as replacement for my brocken one.

here in GErmany the most dealers are crazy with the price. so i serach in the US Shops but what kind of maniford is good?
I found this Maniford at the Web:
http://www.ineedparts.com/index.php?target=products&product_id=15343

so i had an 92th Cherokee HO with stock exhaust - could someone help me.

thanks

1) Like Yucca-Man said, you want to put in a flexible section somewhere between the collector (where all of the primary exhaust pipes come together) and the crossmember (where the first exhaust-to-chassis connection is.) The exhaust is rigidly mounted to the chassis - which has a good deal to do with why it cracks.

2) Check and/or replace outright your engine mounts. Per reports from the field, I'd say that a good 85-90% of exhaust cracks at the collector are due to failed/failing engine mounts. They allow the engine to move to a greater degree - while the exhaust remains rigidly mounted. Those poor welds can only take so much before they give up. Check/replace all three of them - engine mounts should never be replaced singly anyhow.

If you're got failed/failing engine mounts, and they caused your exhaust to crack, your new manifold is going to crack in short order as well. This will not be due to a manufacturing defect - rather, due to improper installation.

Summit carries the stainless flex couplings. http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM%2D642214&N=700+4294923429+4294814707+115&autoview=sku