Anything I should replace when swapping exhaust manifold?

[Lilbomb]

So my exhaust manifold is cracked and loud, i'm going to swap it out but while i'm in there is there anything else I should replace? Jeep has 143,000 miles on it and it's new to me. All I have done is change the oil and filter at this point along with a new air filter. I figure if i'm going to have the intake and exhaust off I might as well do some other maintenance....spark plugs and the like.

Any suggestions from those who have changed the manifold? I think the valve cover is leaking as well so maybe i'll do that at the same time?

Thanks!

 

[Lilbomb]

Also.....what gaskets are the best to use so I don't end up doing this again? Lol The manifold came with one but i'll buy a better one if there is one out there.

 

[mots]

What year of TJ? Which engine?

On my 2005 4.0, if I hadn't already done it, I'd change the midpipe with the 3 cats and all O2 sensors while your in there. The other years\motors are going to be different.

 

[Jerry Bransford]

Hard to beat Felpro gaskets.

Be VERY careful when reinstalling the air intake manifold, don't rush it. It's not easy to get seated so it's air-tight and when it's not, your engine will redline when you first start it from the massive vacuum leak. Make sure the manifold is properly positioned over the short positioning studs and just take your time. At least once a week someone makes a panicked post saying their engine is redlining after replacing the exhaust manifold... invariably from having not gotten the air intake manifold properly seated and air-tight.

 

[KCsTJ]

Use a tap and die to clean the threads in the cylinder as well as the bolt threads.
Cleaning the threads will give you more accurate bolt tightening also be sure to follow the FSM torque pattern.

 

[superduty]

+1 for Fel Pro.

It's a nightmare job. Make sure you have a decent selection of socket extensions and a socket universal joint. Take your time. It's a nightmare job.

Did I mention it's a nightmare.

There are some good guides on the net with some tips and tricks.

Sent from my SAMSUNG-SM-G930A using Tapatalk

 

[04RubiOR]

Hard to beat Felpro gaskets.

Be VERY careful when reinstalling the air intake manifold, don't rush it. It's not easy to get seated so it's air-tight and when it's not, your engine will redline when you first start it from the massive vacuum leak. Make sure the manifold is properly positioned over the short positioning studs and just take your time. At least once a week someone makes a panicked post saying their engine is redlining after replacing the exhaust manifold... invariably from having not gotten the air intake manifold properly seated and air-tight.

Hey Jerry, I’ve always been curious about this. I replaced my manifold gasket a couple months ago. Did my best to seat the intake manifold properly. After finishing the job I started it up. Started up fine. Was idling around 500 rpms. Then I gave it a little gas and it surged to 2000 RPMs and stayed there until I shut it down. I was pretty bummed thinking I was gonna have to start over. I fired the Jeep back up and it idled just fine. Giving it some gas and it worked as it should.

So why did It start up fine on first startup but surged after giving some gas. But since then it hasn’t had any issue? Confused by that initial surge.

 

[Jerry Bransford]

Maybe the manifold wasn't perfectly seated at first but starting the engine caused it to move enough to seat properly. Just a guess.

 

[Alex0413]

I can recommend stubby wrenches, flex head ratcheting wrenches, and wobble extensions to get access and make this job a lot less frustrating...

 

[BugoutJeep]

Maybe I'm late to the party here, but I would think while the exhaust manifold is off, would that give one access to the oil pan? I found that my rear main seal liked to leak a lot. I assume the oil pump is still working well. My oil pump wasn't needed until around 250k miles. I don't want to get in the weeds too much, but I felt like that split seal wouldn't last 100k miles. With the experience of only 1 of these engines, maybe it was just me.