I`ve had my `94 a couple of months, and an exhaust leak has been present since I`ve had it.

I`ve checked the collector flange which seems to be ok. As it warms up, the noise seems to subside, which leads me to believe a crack ?

Are these 4.0 exh manifolds known to crack ?

Thanks

 

uhhh, does this mean no ?

 

You gotta give people 24hrs to respond.

But yes they do crack and it is pretty common.
I just weld them up and good as new again.

 

I have a 99 with the same problem...so i replaced the manifold with an aftermarket header.sounds alot better.

 

Add a flex Joint after the down pipe, it helps a lot.

 

My bad .... I need my info NOW !!!

I plan on replaceing the entire exhaust system .... so I'll weld that sucker up at that time !!!

thanks !!!

 

I had a "NEW" manifold on mine for a month and a week (only after replacing a cracked one with new) then the new one cracked right at the 3rd cyl tube before the collector. I went to the local u-pul it, for $40.00bucks, i scored a used APN HEADER ( NEW THEIR LIKE $ 140.00 ), dont expect any issues with this one, and with 2.5 tubing, no cat and a flowmaster 44, have no complaints!! If i had to do it over again, id just spend the money and buy the new header form the start!! Just my 2-cents (and 40 bucks)!!

 

Thats a good score right there! Yes, the stock mani is very prone to failure, I went to the JY looking for a replacement after mine cracked and out of the 10 or so XJ's there they all had cracked manifolds. i ended up going with the APN header and could'nt be happier.
http://www.ineedparts.com/auto-parts...-manifold.html

 

Cool ... Does the intake and exhaust manilfolds share the same gasket ??

 

Yes.

 

I know guys section the manifold flange to help with the thermal expansion on tubular turbo manifolds. Maybe try that.