roygobert

I'm replacing my cracked exhaust manifold (1999 Cherokee 4.0). Would like opinions and reasons on what kind of manifold to buy and install. I want to stay stock (no headers) but don't want to replace again for cracks. I see stainless for just a few dollars more than cast iron. Any opinions on stainless. Is there engine compartment heat issues with either? Also see the manifolds with expansion sections (2) in them. Are there benefits to this?
Thanks in advance for responses.
Sonny in Chattanooga (1999 Red 2dr Jeep Cherokee, 4.0, Auto, 4X4, 160k miles)

MonacaYankee

I got two of the dorman manifolds with the expansion joints and have not had any problems with either on both of my Cherokees. One is at 4 years and the other at 2.

Replace yours motor mounts and transmission mount to prevent future cracking like I did. Motor mounts at the minimum.

Fred/N0AZZ

If your seeing SS ones for just a few bucks more than Cast Iron, I would avoid them. A good cast manifold should be fine for another 15-16 yrs, most likely a broken mount is your problem with it breaking to begin with. But do check out the entire exhaust system/hangers for damage.

mschi772

You can't really say no to headers when it came stock with a header (albeit a bad one). I'm guessing you said this because of a motivation to spend less money and assumed headers are pricier, so I'll recommend two good budget choices.

Dorman if you insist on a stock clone, but for the same money you can get an APN header that is more durable, performs better, and fits just the same. Sometimes some very minor grinding/filing is needed for it to fit without interference from the 99+ intake manifold.

Disclosure: I went with a Thorley header when my stock header cracked.

roygobert

Thanks for your info folks. Made decisions and ordered from Rock Auto. By far the best pricing even with their shipping prices. Ordered Doorman exhaust manifold and hardware, Walker down pipe and cat converter, NTK O2 sensors, and Westar motor mounts. This should elimate my P0420 trouble code. Maybe a little overkill but why not replace all front exhaust and accessories while in there. Also, I really appreciate the advice about replacing motor mounts. I'll be in touch to follow up on the installation.
Thanks again.

CCKen

Go to the dealer and get an OEM exhaust/intake manifold gasket. There are no aftermarket gaskets to compare. I know from experience,

roygobert

A gasket comes with the manifold. So when the parts are delivered I'll go over to the dealer and check quality of the two and the price on a new one from dealer.
Thanks

CCKen

The OEM gasket has the quality without question.


It's a matter of the holes in the gasket matching the holes in the head. Most aftermarket gasket makers still don't have a clue when it comes to this.


The OEM gasket is impregnated with Graphite , or similar, and provides a great seal. No sealant required when installing it.

thatXJguy

I am running the ATP OEM replacement and it has the two expansion valves on either side to prevent cracking. It comes with a gasket and it works great, so no complaints here. Get it off of Summit Racing for the best price.

MonacaYankee

I used the gasket that came with the dorman manifold on my 94. No problems in two years. Matched just fine. Better quality than the cardboard everywhere except the ports fel-pro one I went to buy instead of using the one that came with the manifold.

Firestorm500

I spent the big money on my '92 and got the replacement from Jeep that has the accordion folds. And got the OEM gasket.

Fit great and no problems after 6 years now.

Madcap

Anybody feel any different about this topic after 7 years? Replacing manifold on a '96, and had same questions. Specifically the cast iron vs. stainless steel thing.

Jeepwalker

The manifolds with the Flex Bellows would be my pick. But honestly, I think a guy is better off fixing yer stock manifold if you have welding skills and like a project. The new ones, while not too expensive, often have terrible (and sometimes massive & constrictive) welds in the exhaust ports, which should be cleaned up. I've bought a couple and after they cracked, I spent some time welding mine up and buttressing common crack areas ....it's been good since. So it's kind of a judgement call.

New Flex bellows are avail too. There used to be less expensive ones on ebay or maybe Summit, maybe there still are. I think the one I bought was like $18-$21 which had the inner sleeve for durability and better flow.

Madcap

Thank you. The mechanic did attempt a weld on the hole last year, but it hasn't held. He's probably not a stud welder though. I have a friend who is, but works out of town all the time. lol FML. I do appreciate you reminding me of that option. Is the thought here based on the original manifold is probably better quality than what is produced now?

FlyinRyan

I bought this one back when it was $86 for my 99 sport and it is a quality piece. Compared it against the cracked up factory one I removed and the flanges are beefy.

Also replaced all the manifold and intake bolts at the time using these

While I was in there I replaced both motor mounts from advise I've seen on this site and boy am I glad I did. Both mounts looked fine, no cracking etc visible but when I unbolted them from the xj wow they crumbled apart.