cracked... it how do I remove it now

I think I cracked my exhaust manifold. How do I remove it is their a way to do it thats easy cause i worked on it for like 2 hours and i need to remove a lot of things. Any special tools you recommend? I hope to just take it off and weld the crack. What should I do about the 2or 3 hangers in the front that cracked also its really hard to weld if your under the car like that and theres no way to really replace them is there??

Part of a 'how to' is on http://www.yuccaman.com/jeep/exhaust.html - you have to remove quite a few bits and pieces to get the manifold off, but it all makes sense once you see parts coming off. My advice would be to get an FSM for exact procedure to follow...

I had a '88 XJ I-6 exhaust manifold off. It didn't require much in the way of special tools to get it off, just the usual sockets, extensions, and swivels. It definitely took all day to pull it and put it back on.

The '88 is gone now. I replaced it with a '92 XJ I-6 with a high output motor. This has a different exhaust manifold, header tubes rather than a casting. I have a crack where the tubes are collected into the cross-over (under the motor to the cat converter).

I don't know which motor you have, but I would be interested if anyone has experience in welding shut cracks in the HO headers. Do the welds hold, or do they just crack again? If you have a cast header... does anyone know if there is any success in welding this type?

Thanks!

mhead said:

I had a '88 XJ I-6 exhaust manifold off. It didn't require much in the way of special tools to get it off, just the usual sockets, extensions, and swivels. It definitely took all day to pull it and put it back on.

The '88 is gone now. I replaced it with a '92 XJ I-6 with a high output motor. This has a different exhaust manifold, header tubes rather than a casting. I have a crack where the tubes are collected into the cross-over (under the motor to the cat converter).

I don't know which motor you have, but I would be interested if anyone has experience in welding shut cracks in the HO headers. Do the welds hold, or do they just crack again? If you have a cast header... does anyone know if there is any success in welding this type?

Thanks!

Click to expand...

Most of the time a weld on a part like that would only hold temporarily. You end up welding it while its cold. When you fire up your rig and get it to operating tempature then the manifold will expand to a certian degree. Most ANYTHING under heat will expand, and shrink when its cold. The constant flex from the heat and cold will end up, sooner or later, exposing the crack you sealed up. Weld it now, and plan on robbing the piggy bank when you can do it right.

mhead said:

I had a '88 XJ I-6 exhaust manifold off. It didn't require much in the way of special tools to get it off, just the usual sockets, extensions, and swivels. It definitely took all day to pull it and put it back on.

The '88 is gone now. I replaced it with a '92 XJ I-6 with a high output motor. This has a different exhaust manifold, header tubes rather than a casting. I have a crack where the tubes are collected into the cross-over (under the motor to the cat converter).

I don't know which motor you have, but I would be interested if anyone has experience in welding shut cracks in the HO headers. Do the welds hold, or do they just crack again? If you have a cast header... does anyone know if there is any success in welding this type?

Thanks!

Click to expand...

All 4.0 XJ headers are tubular. I welded mine up and added some gussets on my 89 and it lasted a couple of years, but eventually cracked in a different location. These headers are made on some grade of stainless steel and over time the material becomes brittle due to the constant heating/cooling effect. An aftermarket stock exhaust manifold can be had for about $175-200, but you may want to look at a performance header (Banks, Thorley, Clifford, Borla) for a long-term solution.

Will a cracked header cause overheating? I've got a exhaust leak on the header and a overheating problem.. I was just wondering if there connected? They seemed to have happend at around the same time.

Thanks, Art-
89 xj 4.0 auto 4x

:hang:

TsfoTo said:

Will a cracked header cause overheating? I've got a exhaust leak on the header and a overheating problem..

Click to expand...

Mine certainly seems to indicate that it's possible. Replaced the cracked header with a ceramic-coated one and although I also replaced the injectors at the same time it certainly runs cooler now. Instead of dumping extremely hot exhaust gasses under the hood they now exit as planned.

There were a few XJ fires in Colorado this summer, and one of the prevailing thoughts was that a cracked exhaust helped elevate underhood temps to the point that they damaged fuel lines; the other train of thought involved tranny leaks hitting the catalytic converter...

So reading these posts just getting it welded is a temp fix. My brother who uses this name to had a newer xj with all the treats. He said to go to a custom shop and get some headers made. I guess he forgot I am not rich and don't have the money to throw into a exhaust. I would think a new manifold and new downpipe would help. Where can I go to get a new exhaust manifold and down pipe?? What should I plan on spending??

anyone have any suggestions on where I should buy a manifold or should I go and buy a performance one.. What should I do. Also How many bolts hold the manifold on??

From what I've seen on the net, unless you buy second-hand, it'll cost you as much as a header....

I got one in the past from these guys... E-BAY lifetime guarantee!
click:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7919227614&category=33632

Under $120 with shipping!

Oops! Wrong year for you! Try their other products, they may have what you need!

Professor Bobo said:

I got one in the past from these guys... E-BAY lifetime guarantee!
click:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7919227614&category=33632

Under $120 with shipping!

Click to expand...

Looks like a great $$ buy! One question however: I have a '92 XJ 4.0 I-6 which is a High Output (HO) motor. I'm told the HO is obtained by head port modification and from a free flowing exhaust manifold. My manifold is different than the one pictured on EBay. I have longer tubes that come from each exhaust port and are collected just prior to the flange to the cross-over (under engine) tube.

Any thoughts on whether the EBay manifold will rob horsepower?

If you had lotsa $$ what manifold would you install?

Professor Bobo said:

I got one in the past from these guys... E-BAY lifetime guarantee!
click:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7919227614&category=33632

Under $120 with shipping!

Click to expand...

Here's a little more info: Contacted the ebay seller who assured me that the manifold replaces the HO manifold. Ordered one. Received it promptly. It is as described on Ebay. All the tubes are stainless steel. The flange that bolts to the head is chromed steel as is the flange to the exhaust tube. Gaskets at both ends were supplied and worked well. It is almost identical to the factory HO manifold except that it has expansion chambers on #1 and #6 tubes. It went on relatively easily except that the rear lower stud on my motor was snapped off and I spent nearly all day buying tools to drill it out and tap in a new one.

Getting the manifold off isn't as bad it looks. Take out the air cleaner. Pull the electric fan. Pull the power steering (just lay it to the side don't disconnect the hydraulic lines). This only takes a couple of minutes. Then you can get the lower nuts with a swivel and extensions. It's only maybe 2 hours off and 2 back on if nothing snaps off.

Oh yeah... disconnect the battery or PROMISE yourself you won't turn the ignition on while the mainfold is off. You have to disconnect the fuel lines and I think the fuel pump will squirt gas everywhere if you turn the ignition on to roll up the windows or some other task.

just an FYI for those who chose to weld it themselves... I tried that twice. Once worked, once didn't. The differance? The first time I laid the thing out on the bench and welded it. I tried to rotate and tack as to avoid distortion, but it didn't work so smooth... the slightest distortion makes it horrible to try to get back on with all the bolts in place.
The second time (another vehicle) I welded all I could get to in place, still tight in the studs. Then, I removed it, and finished up. Also, I added a gusset across the midsection of the tubes. Still doing well to this day.
Note: these were both steel tube factory manifolds, I have never attempted the cast iron rods, although I was told it would work quite well.
Hope this saves someone else the grief!
Best of luck with your repairs.
TheRasper.

How did you all remove the bolts towards the fire wall I still can't reach them.

Have you removed the airbox? That opened up all sorts of room to work...

1989laredoxj said:

How did you all remove the bolts towards the fire wall I still can't reach them.

Click to expand...

IIRC--

9/16" gearwrench

it makes it easier, but still not fun. . .

good luck

I have replaced my headers on my 90 XJ twice. The original exhaust manifold cracked completely in half at about 140,000 miles.

I replaced them with the Pace (I think) ceramic coated headers from JC Whitney. It took me and my brother-in-law about 8 hours to replace. Two years later this set cracked where the two Y pieces join. It was way to close to the front driveshaft and anytime I was driving over rough ground I would hear it bump and scrape.

This time I replaced them with the Borla stainless steel set and really wish I had done this one first because the design and spacing was much better. It has never hit the driveshaft and so far has been going three years with no problems. The second time around it took us around 5 hours to replace.

I now have over 260,000 miles and still going strong.

Those back bolts were hard to get to. It took some perseverance on our part. I think we had to get them loose with a wrench because there is not enough space for a rachet. Make sure when you put them back together that you torque the bolts to the right specs (except those back bolts you will have to guess at because you cannot get a normal torque wrench back in there).

i would go the buy new ones route unless you're a great welder.
cast products (iron ones) can be welded...try using a higer nickel content filler mat'l for some stretch and if you have access to some sort of oven preheat helps.
again...the cost of finding a welder who will provide any sort of gaurantee for cracking will prolly end up costing as much...IMHO.