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TJ exhaust crack advice

Hi guys, A few months back I noticed my 98 tj exhaust manifold (6cyl) was cracked at the weld where the two main pipes join the flange. The top pipe weld has the crack, its about 1.5" right on the top area. No noise. It hasn't gotten worse all winter. In your experience, will it get worse? I have 70k miles and I don't do any serious offroad. I'm looking for an excuse to not do the job. Should I wait until it gets worse or just go ahead and do it now? My plan, if I do it, is to get the one from 1A auto that some guys here have gotten. Any surprises in doing the job? Will the bolts from the engine come out easily, or should I plan on breaking one? If they come out easily, should I re-use the bolts or get new ones? Will the old gasket come out cleanly or will I have to spend some time scraping and cleaning. Dumb questions, I know, but I find I have a much more enjoyable job when I think it through first and there are no surprises. Thanks for any tips and advice. -Nick

Reply to
NickT
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Yes, it will get worse.

Reply to
jbjeep

Yeah, it will probably get worse. Mine sure did anyway, ended up with cracks in a couple different places even. I procrastinated until I couldn't stand the noise anymore, but probably should have replaced it sooner. As far as installing a new one (I opted for a header instead though), it was pretty straight forward. Bolts didn't break, and I re-used them. Old gasket came right off, so no cleaning. Only 'gotcha' I ran into was that I didn't get the header properly seated over the little manifold stud pegs the first time. Created one heck of a vacuum leak, and the engine would rev WAY high when started (like someone was flooring the gas pedal).

Dave

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Reply to
David C. Moller

I had the same problem on my 97. I waited until the crack became hugh. That became a hidden problem. When i put the borla header on, i got check engine light to come on and had 4 error codes. Dont wait. change it now before the computer brain starts to adjusting the fuel/air mixture and other things. Hope this helps you. Got the codes of in about a week. the computer brain need to learn the new settings it was getting.

aXeman

Reply to
aXeman

SO....then a question is.... any sort of "flow adjustment" would change the performance...so, maybe dropping the battery cable off and resetting the computer??

Reply to
SB

Not sure... when I replaced my manifold with a header, it idled a bit high (1000-1100) for about a day until (I assume) the computer reset itself. This was even after the battery had been disconnected during the entire installation process. No check engine light for me though.

Dave

Reply to
David C. Moller

hmm....well, I'm sure the computer 'keeps' memory with power failures. But this was a much suggested way to get it to adjust faster....

Reply to
SB

Maybe it was faster.... might have taken three days to adjust if my battery hadn't been disconnected hehehehe. :)

Dave

Reply to
David C. Moller

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