Chick-N-Picker

89 jeep XJ 4.0 auto 4x4 82,000 miles.

Well since I've posted about the fuel pump issue it has been solved and has ran fine for going on 2,000 miles.

My jeep has no cat converter or muffler. I know it's illegal but it's all due to my stupid thief cousin.

Anyway my jeep runs fine but I do have a spot where my exhaust manifold gasket is blew out some (see picture). I know it can hurt gas mileage but I'm getting around 17-18 mpg on 235/75/15. But is it hurting my motor?, and if it is, Is there some kind of epoxy/gel I can buy to smear all around the crack until I can afford a whole new exhaust?

Orlo

Uhhhh. Sounds like you may have a cracked exhaust header. I'd say it's time to give the old beast a full new exhaust. You will not fix a cracked manifold with any sealant. Buy the whole thing, cat and all. Replace it. You will be legal, quiet and keep the engine running properly.

Chick-N-Picker

I have a new cat from a guy I read about on the forum who makes them. It's not direct fit, of course.

I have a new tail pipe. The original muffler is still ok.

I do need a new upper exhaust pipe. A new exhaust manifold & manifold gasket. Is that all that goes to the exhaust system. What's the cheapest place to buy an exhaust manifold? I seriously don't have any extra funds at the moment.

Also I know doing this job is horrible because first you have to tear down so much (TB, fuel rail, injectors, intake manifold, electricals, etc) just to get to the EXMan. Then it's stuck bolts to the max. Then if all the pipes are not put back straight they will vibrate and crack the new one. (Should only be 2 welds)

I know it's ideal if I do it now but will it hurt my jeep to drive it the way it is now or is so serious I need to park it immediately.

Chick-N-Picker

Edit: I wanted to come back and say. I don't think I actually have a cracked exhaust manifold.

I thought it showed in the picture. It's just a little piece of the EX Man gasket is hanging out. I guess a bolt got loose and it blew out a small piece but not all the way out. Maybe I could try to loosen the bolt and put some sealant on it and tap it back in then retighten.

jmrec100

Jeeps are known for cracked exhaust manifolds.

I tried sealants too. Used hi temp Ceramic on the exhaust manifold. Good to 2300F. But when they crack and leak, thee are hairline cracks you won't see. Keep us posted what you do to fix it.

Chick-N-Picker

Will do. I don't think the ex manifold is cracked but in case I check it and it is. I have a parts 94 jeep cherokee that I know isn't cracked. I wonder if a 94 can go on an 89?

It doesn't have to be inspected until January so I'll have to do something by then. Hopefully driving it this way will not hurt it for 3/4 months.

I've read of cars running for years and years with cracked exhaust manifolds. I've also read of them burning valves. It's actually a lot of confusing and contradicting info about this subject. Either way I want to fix as soon as possible. I just wanted to check and see if it was ok to drive for a few months without hurting anything.

Orlo

No short cuts. They won't work with your exhaust issues.

You should research how to change your exhaust manifold. Lots of info on this site and YouTube. Even if it isn't cracked, the gasket may have been compromised and that needs to be changed. The intake manifold and exhaust manifolds use a common gasket and fasteners. Chances are you have an issue that will go beyond an exhaust leak.

Get the parts, get some aero kroil penetrant to spray on the mounting hardware. Best stuff on the planet. Then get some knowledge. If your rig is otherwise nice, it deserves a decent exhaust.