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possible exhaust manifold leak

60K views 22 replies 11 participants last post by  glinden94 
#1 ·
im 99.9% sure my manifold is leaking or cracked, so whats the easiest way to diagnose this issue without pulling the whole thing apart?

also, if/when i have to pull it apart, how do i do that? im afraid these bolts are so rusted into place that they will snap or something.
 
#2 ·
Stuff a potato up the tail pipe if you are alone.
If you have help, have a victim hold a rag over the tail pipe blocking it off. Engine running of course.

You'll hear every place it's leaking.


And yeah those bolts can be a bugger. Apply liberal amounts of PB Blaster to em and let em soak, repeat. Hope for the best. If they break, time to dig out the drill and EZ-outs.......
 
#3 ·
X2 on a rag (never tried a potato lol)

also seafoam will cause it to leak from the cracks, not a bad idea to seafoam it anyway, you will see every crack for sure lol, also to determine if it is the header leaking or a lifter just open the throttle slowly by hand and listen to the ticking, if it goes away when you open the throttle (usually 1000-2000 rpms will do) then it is a lifter, it will stop ticking when you open the throttle because the extra oil pressure will force it into the lifter, if the ticking gets worse when you open it, its an exhaust leak
 
#4 ·
BTW if it is the header, autozone sells a nice one pretty cheap, it has the built in expansion joints to keep it from cracking (learned this from another WF member) im about to buy one after i finish moving next week, heres the header- Dorman/Exhaust Manifold (674-196) | 1999 Jeep Wrangler 4WD 6 Cylinders S 4.0L MFI | AutoZone.com_
if yours is like mine and has cracks after the collector (downpipe) autozone sells that too - Walker/Exhaust Pipe (53458) | 1999 Jeep Wrangler 4WD 6 Cylinders S 4.0L MFI | AutoZone.com_ good prices on both, i think you can find the header on ebay just a tad cheaper but if you need both might as well order them at the same place, plus it is easier to bring it back to autozone in the event it fails then mail it back for the warrenty, IMO

those are for the 4.0 btw im sure they have the 4cyl version as well just look on autozone.com if you dont have a I6
 
#15 ·
Any who has put on a header, did you put on new exhaust? And, have you made any other mods to engine? DID YOU NOTICE A DIFFERENCE? Power? Fuel milage? Been thinking about doing the same to mine. I want to boost the power before going to a tire larger than a 31x10.50. My 06 seems to be lacking in power since I put them on. Trying not to get into the axles until I have to.
 
#17 ·
I'm doing this...again...next week. I replace 2 on my YJ, one on my GC/ZJ, and now this is the second one I have done on my 2001 TJ. I have typically hunted down a used OEM one without cracks because I knew I wouldn't keep my Jeeps forever but this TJ is my love :redface:

I will probably go with one of you guys and get either the Autozone manifold or an eBay one but I have noticed that they don't seem to have the expansion valves when you search for 2001 TJ. Anyone know why?:banghead:
 
#18 ·
I'm doing this...again...next week. I replace 2 on my YJ, one on my GC/ZJ, and now this is the second one I have done on my 2001 TJ. I have typically hunted down a used OEM one without cracks because I knew I wouldn't keep my Jeeps forever but this TJ is my love :redface:

I will probably go with one of you guys and get either the Autozone manifold or an eBay one but I have noticed that they don't seem to have the expansion valves when you search for 2001 TJ. Anyone know why?:banghead:
i thought they had changed the design of the header in the later TJ years to help fix the cracking, maybe thats why the 01 doesnt show the expansion joints? im not 100% sure tho
 
#21 ·
Hello all! I am new to this forum and working on Jeeps in general. I recently bought a 2002 TJ sport. I bought the car knowing the engine light was on and it ran the lean engine codes for both the front two banks. I first replaced my 02 sensors. Nothing. Then I checked for leaks in the vacuum lines and didn't see any. Further research showed that it could be a leak in the intake/ exhaust gasket which would be allowing the excess air in (plus I always thought the Jeep was extra loud). To test this theory, I used my shop vac (on reverse) and put it into the tailpipe. I then sprayed soapy water throughout the exhaust (upstream of the two mini cats) and found bubbles at the gasket (right next to the number 6 bolt/nut). I have now replaced the gasket and re-torqued the intake to the block. Before I wasted any more time putting the car back together, I performed the leak test again. I am still leaking at the number 6 bolt/nut and now seem to be leaking at the number 3 bolt. I'm assuming this is not supposed to happen (even though I'm pumping air into the exhaust while it will normally be flowing the other direction). Please help! Any guidance is much appreciated!
 
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