APN Header Install...

[jk_surgeonfish]

For those of you with cracked exhaust manifolds here are some things I learned when doing the new header install. (1st time doing this for me) I installed new motor mounts 3 days prior to this as well.

I pulled the intake and exhaust the day before the parts showed up and was able to spend some quality time cleaning up the intake and the ports on the block. It was nice not to have to rush and do it all in one day. Getting the stock 4.0 exhaust and intake off was pretty easy.

APN arrived FedEx 3 days after ordering. Cost for header and shipping was $150. Came with new intake/exhaust gasket, nuts and bolts for exhaust flange and a new donut gasket.

Started install.... Son of a ...... there is one bolt that took me 2 hours trying to get it back on. Got pissed off... said some things I don't think my kids or the neighbor kids should have heard. Took the whole thing off thinking I stripped the threads. Then the "DUH" moment arrived and I threaded all the bottom bolts before putting the intake on. This was the trick. Once that was on I was able to torque all but 2 of the bolts. The 2 most difficult one to access I was able to get by using a ratchet wrench... had to guess on how tight to get it.

After hooking the rest of the crap up... fired it up and smoked the garage out for a bit due to all the grease on the new header.

Some things I noticed after starting: 1. no more exhaust leak.. woo hoo 2. starts faster... probably result of cleaning intake out really good.... 3. more power.... not a lot but I can feel a bit more.

It smells a little like burnt rubber right now but I think that is just the new gasket... at least I hope so.

So if you are thinking of doing this give yourself lots of time. Next time it will be faster... uh wait.. there will not be a next time, at least I hope not.

[chopped7]

i always give myself plenty of time. i'm currently going on 5 yrs replacing the headers on my cj.

[smak45]

Oh there will be a next time. And a next and a next and a next........ I gave up.

[KennethS]

This is what replaced the cracked exhaust manifold on my TJ:

http://www.bankspower.com/products/show/221/54

Unlike the stock, failure-prone exhaust manifold, Banks TorqueTube is built of heavy, 409 stainless steel to weather a lifetime of heat, stress and abuse. The flange, welded to the tube assembly on both sides, will never crack or separate.

[Semper Fi CJ-5]

This is what replaced the cracked exhaust manifold on my TJ:

http://www.bankspower.com/products/show/221/54

Unlike the stock, failure-prone exhaust manifold, Banks TorqueTube is built of heavy, 409 stainless steel to weather a lifetime of heat, stress and abuse. The flange, welded to the tube assembly on both sides, will never crack or separate.

Nice. How do you like the sound difference?

[jk_surgeonfish]

The APN header is definitely beefier than the old stock one. This is where I ordered it from: http://www.ineedparts.com/auto-parts...l=EN&currency=

After driving around with it for a few days now.. definitely more power and I think the combination of no more exhaust leak and new 02 sensor I can tell that the gas guage is dropping a lot slower. I'll know for sure now that I just filled up the tank as to what my mileage will be once I go through this tank.

[KennethS]

Nice. How do you like the sound difference?

It was amazing. I had gotten so used to the loud "clack clack clack" sound of the broken manifold I had forgotten what it was like to be able to listen to the radio while the engine was running!


Seriously, as far as I could tell, there was no difference in sound. I did not change the muffler and the pipe is still factory out to the back of the vehicle, though.

If you want a different sound, install a performance muffler.

[skullcaps]

I also replaced my cracked header with an APN for my 4.0L YJ. Great header for the price, and I was happy to get rid of my loud exhaust leak. But, I obviously did something wrong during the install, or perhaps the header was defective, because now my jeep whistles like crazy at no throttle and when the engine is warm. How am I supposed to look cool driving a whistling jeep? lol. If the intake manifold is pulled up, the vacuum leak/whistle changes pitch (thanks behemothxj) so I'm pretty sure I didn't tighten the bolts to the correct torque or in the correct pattern. Looks like I'll be reinstalling it.

[jk_surgeonfish]

I also replaced my cracked header with an APN for my 4.0L YJ. Great header for the price, and I was happy to get rid of my loud exhaust leak. But, I obviously did something wrong during the install, or perhaps the header was defective, because now my jeep whistles like crazy at no throttle and when the engine is warm. How am I supposed to look cool driving a whistling jeep? lol. If the intake manifold is pulled up, the vacuum leak/whistle changes pitch (thanks behemothxj) so I'm pretty sure I didn't tighten the bolts to the correct torque or in the correct pattern. Looks like I'll be reinstalling it.

That sucks! I took extra time with a mirror to make sure that the dowels on the block were in the holes on the intake. Then hand tightened it all and torqued them. No whistling for my Jeep. Runs great.