Options for cracked exhaust manifold replacement on 2.5?

[zlandquist]

The first one you cannot tell if it's Oem, the second one looks to be Oem but the broken studs have to be removed and the third Is not Oem.

If you notice the plugged outlet just above the downpipe connection that is for the earlier 2.5's and although it will fit, TJ 2.5 manifolds did not utilize that connection as you can see in the second link. That capped outlet can be a failure concern ( had 2 of them fail ) as I mentioned above. If an Ad states it's for a 91 to 02 wrangler 2.5 then it will have the plugged outlet, correct manifold would be 97 to 02.

Thanks for the insight. It's crazy the amount of stuff there is to learn. Thanks!

 

[Chris]

They do tend to suck for the 2.5 also but unless you want to drop coin on a Banks direct replacement there are very limited options out there, I'm just glad it has held up this long. Hopefully going TDI diesel in the near future.

See, even my Banks headers cracked after 2 years on my XJ. Then I came to find out they are also made in China (surprise, surprise). Maybe I just have bad luck!

TDI would be a great choice though!

 

[RaymondT]

I've been down this road a few times in the last year. The Mopar one is a cheap Chinese "universal" manifold for 84-02 years. The casting where the cone washers captures both the intake and exhaust tabs are too thick.

I found the Dorman one to fit better and so far it's out-lasting the Mopar one. The thickness of the tabs is equal to the intake manifold and it comes with a decent gasket. Either way you go, make sure you have all the proper hardware to mount including the spacers on the two outside studs. Then super-important; torque it following the REVISED factory procedure. The outside studs are torque to inch-lbs which doesn't overstress #1 and #4 outside pipes otherwise they will break here. Also, for our fuel injected engines, drill out the rivets on the shielding and pitch the shields in the garbage. They are for carb preheats and just get in the way.

 

[zlandquist]

I've been down this road a few times in the last year. The Mopar one is a cheap Chinese "universal" manifold for 84-02 years. The casting where the cone washers captures both the intake and exhaust tabs are too thick.

I found the Dorman one to fit better and so far it's out-lasting the Mopar one. The thickness of the tabs is equal to the intake manifold. It comes with a decent gasket. Either way you go, make sure you have all the proper hardware to mount including the spacers on the two outside studs. Then super-important; torque it following the REVISED factory procedure. The outside studs are torque to inch-lbs which doesn't overstress #1 and #4 outside pipes otherwise they will break here.

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Thanks! I will keep this in mind! Much appreciated

 

[oldtimer]

I've been down this road a few times in the last year. The Mopar one is a cheap Chinese "universal" manifold for 84-02 years. The casting where the cone washers captures both the intake and exhaust tabs are too thick.

I found the Dorman one to fit better and so far it's out-lasting the Mopar one. The thickness of the tabs is equal to the intake manifold and it comes with a decent gasket. Either way you go, make sure you have all the proper hardware to mount including the spacers on the two outside studs. Then super-important; torque it following the REVISED factory procedure. The outside studs are torque to inch-lbs which doesn't overstress #1 and #4 outside pipes otherwise they will break here. Also, for our fuel injected engines, drill out the rivets on the shielding and pitch the shields in the garbage. They are for carb preheats and just get in the way.

View attachment 139275View attachment 139276View attachment 139277

Any idea where I can get the spacers for the studs? I can’t find them anywhere. I have all the other hardware needed and want to get this project started. Thank you

 

[TJ4Jim]

Any idea where I can get the spacers for the studs? I can’t find them anywhere. I have all the other hardware needed and want to get this project started. Thank you

There is no need for the spacers and I have never seen one since owning 2.5's for 12 years.

 

[RaymondT]

I made the two spacers out of brass as mine were missing. Their purpose is to center/position the manifold when you first slide it on. They have to be shorter than the depth of the casting as to not effect the clamping force.

 

[oldtimer]

Thank you both for the reply. I start tearing it apart tomorrow morning. Keeping my fingers crossed for a smooth job.

 

[SSTJ]

Loving this thread. Any update on how the installation went? @zlandquist @oldtimer

Also @RaymondT thank you for the pro tips. Is this the Dorman that you used?

 

[SSTJ]

I've been down this road a few times in the last year. The Mopar one is a cheap Chinese "universal" manifold for 84-02 years. The casting where the cone washers captures both the intake and exhaust tabs are too thick.

I found the Dorman one to fit better and so far it's out-lasting the Mopar one. The thickness of the tabs is equal to the intake manifold and it comes with a decent gasket. Either way you go, make sure you have all the proper hardware to mount including the spacers on the two outside studs. Then super-important; torque it following the REVISED factory procedure. The outside studs are torque to inch-lbs which doesn't overstress #1 and #4 outside pipes otherwise they will break here. Also, for our fuel injected engines, drill out the rivets on the shielding and pitch the shields in the garbage. They are for carb preheats and just get in the way.

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Hey @RaymondT ,

This is really helpful. Can you tell me where you found this revised approach? Just compared it to my 97 FSM, and sure enough, the step that you boxed in red is different in mine. Makes me wonder what else I should not trust in my FSM.

 

[Mike P.]

Hey, everyone. I appreciate all the info here and the other threads I've read through, too. I just want to confirm I am correctly assessing what I see under my hood in the attached photos.

2001 SE 2.5L 5 speed

• Exhaust leak sounds to be on top side rather than bottom side
• 3rd party exhaust manifold with tabs much thicker than stock intake manifold installed by previous owner
• Half-washer on shared mounting points trying to shim the intake tab thickness but probably not doing the trick
• Bolt #1 missing
  • Would this most likely be due to the thicker exhaust tab preventing thread engagement?
  • If I find a stud was sheared off in the block, where do I go from there?
• Do I need to remove the fuel rail and/or injectors from the intake manifold for this job?

Tools & Supplies

1. 14 mm flex socket, 14 mm ratcheting wrench, fuel line disconnect tool, flex head ratchet and extensions.
2. I'll plan on grinding the exhaust flange tabs in plane with the intake flange tabs.
3. I'll clean the throttle body and replace the throttle body gasket at the same time.

Do I have my ducks in a row? Any suggestions on what to expect for Bolt #1 would be appreciated, as would any other suggestions.

 

[TJ4Jim]

I would try and find a used oem manifold rather then dealing with the aftermarket crap which is what I did last fall, I went thru 2 of those with the same casting issues. They aso leak badly from the plugged off O2 sensor port that was used on the earlier YJ engines.

https://www.ebay.com/itm/1276257189...pid=5337789113&customid=&toolid=10001&mkevt=1

https://www.ebay.com/itm/1275292126...pid=5337789113&customid=&toolid=10001&mkevt=1

 

[tworley]

• 
  
• Bolt #1 missing
  • Would this most likely be due to the thicker exhaust tab preventing thread engagement?
  • If I find a stud was sheared off in the block, where do I go from there?

If its a busted bolt with half in the block still you could try a pair of vise grips, welding a new nut on, or drill it out.

• Do I need to remove the fuel rail and/or injectors from the intake manifold for this job?

The fuel rail, manifold, vacuum lines, throttle linkage, intake tube all have to come off. It helps even more if you can take the driver side fender off too.

Any suggestions on what to expect for Bolt #1 would be appreciated, as would any other suggestions.

Lots of extensions, and would recommend you remove the driver side fender.

 

[Mike P.]

I would try and find a used oem manifold rather then dealing with the aftermarket crap which is what I did last fall, I went thru 2 of those with the same casting issues. They aso leak badly from the plugged off O2 sensor port that was used on the earlier YJ engines.

https://www.ebay.com/itm/1276257189...pid=5337789113&customid=&toolid=10001&mkevt=1

https://www.ebay.com/itm/1275292126...pid=5337789113&customid=&toolid=10001&mkevt=1

Thanks for the links, @TJ4Jim. I see only three mounting bolts for the OEM manifold - is that right? Must be, but I'm surprised enough to ask again haha

 

[TJ4Jim]

Thanks for the links, @TJ4Jim. I see only three mounting bolts for the OEM manifold - is that right? Must be, but I'm surprised enough to ask again haha

Yep thats correct, those aftermarket manifolds aren't worth the effort to repair... also I doubt you'll bust any bolts in the process.

 

[Mike P.]

Thanks for the confirmation, @TJ4Jim . I think I'll snag that OEM unit you suggested. Should I plan on getting that resurfaced? Any other prep I should plan on?

In the meantime, am I going to do any damage driving a couple hundred miles over a couple weeks with an exhaust leak? It sounds like a Volkswagen Beetle with peashooter exhaust.

 

[TJ4Jim]

Thanks for the confirmation, @TJ4Jim . I think I'll snag that OEM unit you suggested. Should I plan on getting that resurfaced? Any other prep I should plan on?

In the meantime, am I going to do any damage driving a couple hundred miles over a couple weeks with an exhaust leak? It sounds like a Volkswagen Beetle with peashooter exhaust.

Surface should be fine, worst case touch up with a file if necessary. Get a felpro gasket, a fuel line disconnect tool (to remove the rail) and some manifold to downpipe hardware (see link). After replacing be sure to re-torque the bolts after a few runs since they tend to loosen.

https://www.napaonline.com/en/p/NOE...&ranSiteID=je6NUbpObpQ-t4EIOxjTM1U3QpOhPVrE5g

 

[Hacker412]

I just went through this with my jeep. I replaced it with an afe header. While you are there, maybe fabricate a heat shield? Check out your motor mounts, too. Easier to replace while you have it apart.

 

[SSTJ]

Hey, everyone. I appreciate all the info here and the other threads I've read through, too. I just want to confirm I am correctly assessing what I see under my hood in the attached photos.

2001 SE 2.5L 5 speed

• Exhaust leak sounds to be on top side rather than bottom side
• 3rd party exhaust manifold with tabs much thicker than stock intake manifold installed by previous owner
• Half-washer on shared mounting points trying to shim the intake tab thickness but probably not doing the trick
• Bolt #1 missing
  • Would this most likely be due to the thicker exhaust tab preventing thread engagement?
  • If I find a stud was sheared off in the block, where do I go from there?
• Do I need to remove the fuel rail and/or injectors from the intake manifold for this job?

Tools & Supplies

1. 14 mm flex socket, 14 mm ratcheting wrench, fuel line disconnect tool, flex head ratchet and extensions.
2. I'll plan on grinding the exhaust flange tabs in plane with the intake flange tabs.
3. I'll clean the throttle body and replace the throttle body gasket at the same time.

Do I have my ducks in a row? Any suggestions on what to expect for Bolt #1 would be appreciated, as would any other suggestions.

View attachment 671634View attachment 671635View attachment 671636View attachment 671637

I haven't read your post in detail, but just wanted to share that I put my notes on replacing the 2.5 manifold here.

 

[Mike P.]

I haven't read your post in detail, but just wanted to share that I put my notes on replacing the 2.5 manifold here.

Thanks for the thorough coverage, @SSTJ!