Jeep question

[Chuck52]

Jeff,

I'm on a short time string for this little road trip. No time to work on it down there in sunny Florida. My boy's on the JFK. You may have read about their adventures getting combat ready for deployment to... wherever the next place is which requires an attitude adjustment. I had a brief time frame in which I could zip down there, pick up the Jeep, maybe see the boy, and drive back here. Now it's not clear just where the ship will be when I get to Mayport, but at least picking up the Jeep has been arranged for even if sonny boy is out playing in the ocean. When I get it back home I'll look at it to see if I think I can reasonably do the job myself. I'll at least have six months before he comes looking for his baby. Some of you guys think you're attached to your tractors, but my boy is <font color=red>really</font color=red> attached to his Sahara.

Chuck

 

[RichS]

I can relate to him being "Attached" to his Sahara. I bought mine new in 1989. Although it is no longer my daily driver, I don't think I will ever get rid of it. /w3tcompact/icons/smile.gif

 

[MarkV]

Chuck,

I am about as far from being a mechanic as one can get./w3tcompact/icons/smile.gif Although I did have an old Chevy Blazer that had a V8 with headers on it and a small hole developed about 2” from the exhaust port. I was told that as the colder than normal air was drawn into this hole it caused a valve to warp. Of course they would probably tell me anything rather than back the engine they built.

Might be worth a stop at a Jeep dealer and talk to the service Manager.

MarkV

 

[Rowski]

Chuck

I think jeep came out with a better designed exhaust manifold. I have changed a few manifolds on those in-line 6 cylinders. You need to remove quite a bit of "stuff" including the intake. As other have mentioned, a cracked manifold can: You can get fumes into the passanger compartment. Add oxygen to the exhaust upstream from the lamda (oxygen sensor) sensor which can mess-up the fuel management and possibly set the "check engine light". Have hot exhaust gases (if crack is bad enough)directed on brake lines, wiring harness, hoses, etc.

I would love to change a manifold on a southern car. The last one I did was a 1996 jeep and I had to do a lot of heating and got bloody knuckles!

 

[Joe_W]

In my previous life I was in the auto service business in a Chevy dealership as a parts manager. I have seen burnt valves resulting from broken, cracked, and gasketless exhaust manifolds. As has been suggested before, the damage doesn't occur while you are driving, but rather as the engine is cooling. If a portion of the valve cools quicker than everything else, it will lose its temper ( no it won't get mad, it will soften the metal). Then when you get the engine up to operating temperature, that softer area on the valve will burn away, leading to an expensive repair involving removing the cylinder head. If the crack is small enough and you feel real lucky, you may get by. If it's a possibility, you may want to consider putting it on a trailer and taking it home. Good Luck!!
Joe W.

 

[Anonymous Poster]

If the crack is in a spot you can get to, use some plastic furnace cement to close it up. Let the cement set up a few hours before you start the engine.
I know of a few that have made it all the way to the crusher with furnace cement on exhaust manifolds.

 

[Chuck52]

Thanks Franz. I was wondering if there might not be some kind of temporary fix possible. I seem to recall a kind of tape you used to be able to get for fixing holes in exhaust pipes and mufflers. I'll try to find some of that furnace cement and hope the crack is where I can get to it. Is it something like a high temp J-B Weld? I've fixed a number of things with that stuff, but I doubt it would take the heat of an exhaust manifold.

Chuck

 

[Anonymous Poster]

Furnace cement is a product that's been around for longer than I have. I've seen it on old coal furnaces, and I've used it on wood burners with fit up problems.
It does become brittle over time, and you don't want to buy a larger can than you are going to use, but it is great stuff when you need it.

 

[Chuck52]

I was at the auto parts store and found a product they sell for exhaust manifold repair. I bet it's the same thing as furnace cement, but in a smaller size for more bucks. It was maybe a 2 oz jar for $6.99, and I saw a pint of furnace cement for a few bucks. However, I'll probably buy the auto parts stuff when I get to FL because it may be easier to find there. I figure if I try to carry that stuff on the plane with me they'll lock me up. I'm not taking my pocket knife, which I always carry, or even finger nail clippers. It figures that I would be flying on a one way ticket to a city with a major military base on the first day of the increased airport security measures.

Chuck