Snapped manifold bolt

StG58

StG58

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Orygun, the wet side...
It had to happen eventually.

The four angry squirrels spit out an exhaust manifold bolt. Unfortunately, I only have three days to fix it. Fortunately it's the first bolt on the front of the manifold.

It appears to be snapped off flush with the head, oh joy! I'll know more when I finish my cup of coffee and get out the inspection mirror.

Edited to add: Yup, snapped off one thread inside the head. It appears to have been failing for awhile as the break isn't clean all the way across.
 
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Ernie Stripling said:
Keep us in the know as that same procedure is in my future. What is your model and year?

Sent from my VS990 using Tapatalk
Click to expand...
Hello Ernie,
I've got a 1999 TJ SE. 2.5 liter four cylinder, manual transmission, only minor modifications and only minor irritations so far. Zero option TJ, except for air conditioning. Why it has air conditioning, I have no idea.

With my first attempt, I'm going to soak the busted bolt with penetrating fluid for a day or so. Remove the accessories from the front of the engine for access. Get out my good drill bit set and a new stud extractor and attempt to extract the broken stud. If that doesn't work, then I'll have to remove the intake and exhaust manifolds and all that entails to do a more thorough job of drilling and extracting. I'm not holding my breath that this is going to be fast and easy. If the manifolds come off, all the bolts / studs are getting replaced at the same time.
 
i feel your pain. You probably read that i just went through this with my 2.5 but with the rear most bolt. I had to have a shop do it cuz i could not get a drill back there. It took them hours and had to use a helicoil to rethread it.

My only tip is to heat up the surrounding area to expand it before attempting to extract the broken bolt.
 
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Ahoragi said:
i feel your pain. You probably read that i just went through this with my 2.5 but with the rear most bolt. I had to have a shop do it cuz i could not get a drill back there. It took them hours and had to use a helicoil to rethread it.

My only tip is to heat up the surrounding area to expand it before attempting to extract the broken bolt.
Click to expand...

Good tip, thank you. What type of e-z-out did you try? The straight "blade" ones or the spiral "blade" one? On those smaller bolts, it's been my experience that both styles tend to expand the bolt into the threads, jamming them harder as they wedge in. I'm not to hopeful that this is going to be a fast and easy fix. I'll do the penetrant soak and contemplate it. I just may drill the bolt out and go straight to a larger bolt with fresh tapped threads or a helicoil.

Yah, I was just going to search for your thread on that subject to get my head in the right frame of mind. I got lucky, kinda, because mine is the front bolt. Exhaust manifold bolts are Satan's spawn. I hate them. The Suburban has a rear exhaust manifold bolt that snapped, and needs fixin' as well.

The manifold is leaking just enough air into the system that it's throwing the air fuel mixture off. (Exhaust dilution, the computer thinks the engine is running lean) Not enough to throw a code, but enough to where the gas mileage dropped noticeably and you can hear the leak when the engine is colder.

How come things like this only happen when you have two big trips planned back to back and the TJ is the only rig that fits the bill? Are the TJ gods pissed at me because I looked at non-Currie control arms or something?
 
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StG58 said:
Good tip, thank you. What type of e-z-out did you try? The straight "blade" ones or the spiral "blade" one? On those smaller bolts, it's been my experience that both styles tend to expand the bolt into the threads, jamming them harder as they wedge in. I'm not to hopeful that this is going to be a fast and easy fix. I'll do the penetrant soak and contemplate it. I just may drill the bolt out and go straight to a larger bolt with fresh tapped threads or a helicoil.

Yah, I was just going to search for your thread on that subject to get my head in the right frame of mind. I got lucky, kinda, because mine is the front bolt. Exhaust manifold bolts are Satan's spawn. I hate them. The Suburban has a rear exhaust manifold bolt that snapped, and needs fixin' as well.

The manifold is leaking just enough air into the system that it's throwing the air fuel mixture off. (Exhaust dilution, the computer thinks the engine is running lean) Not enough to throw a code, but enough to where the gas mileage dropped noticeably and you can hear the leak when the engine is colder.

How come things like this only happen when you have two big trips planned back to back and the TJ is the only rig that fits the bill? Are the TJ gods pissed at me because I looked at non-Currie control arms or something?
Click to expand...
The TJ gods are pointing out a problem BEFORE it leads to more problems:)
Good Luck!
 
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I've never had much luck with extractors. Get a LH drill bit. Honestly though, the best luck I've had is a punch sharpened to a point and a hammer. Use the punch along the outside of the bolt and tap it in a CCW direction to try and spin the bolt out. Heat is also your friend.
 
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OK, would someone confirm the stud size as 3/8"x16 - 3/8" x 24 x 1.75 long (P/N #6036 193AA) and a P/N #6036 045AA manifold retaining washer? I got that out of the FSM, but would like verification.

Oh, and a new 3/8"x24 steel nut.
 
StG58 said:
Good tip, thank you. What type of e-z-out did you try? The straight "blade" ones or the spiral "blade" one? On those smaller bolts, it's been my experience that both styles tend to expand the bolt into the threads, jamming them harder as they wedge in. I'm not to hopeful that this is going to be a fast and easy fix. I'll do the penetrant soak and contemplate it. I just may drill the bolt out and go straight to a larger bolt with fresh tapped threads or a helicoil.

Yah, I was just going to search for your thread on that subject to get my head in the right frame of mind. I got lucky, kinda, because mine is the front bolt. Exhaust manifold bolts are Satan's spawn. I hate them. The Suburban has a rear exhaust manifold bolt that snapped, and needs fixin' as well.

The manifold is leaking just enough air into the system that it's throwing the air fuel mixture off. (Exhaust dilution, the computer thinks the engine is running lean) Not enough to throw a code, but enough to where the gas mileage dropped noticeably and you can hear the leak when the engine is colder.

How come things like this only happen when you have two big trips planned back to back and the TJ is the only rig that fits the bill? Are the TJ gods pissed at me because I looked at non-Currie control arms or something?
Click to expand...

I did not try to extract it because i could not get a drill back there. It was either remove the head to do it on a bench or let a shop tackle it. I needed new body mounts welded in so I had the shop do both.
 
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Ranger_b0b said:
I've never had much luck with extractors. Get a LH drill bit. Honestly though, the best luck I've had is a punch sharpened to a point and a hammer. Use the punch along the outside of the bolt and tap it in a CCW direction to try and spin the bolt out. Heat is also your friend.
Click to expand...
Me neither. The extractors just seem to wedge the busted bolt into the hole tighter. I like the idea of a LH drill bit though...soak it down, drill it out and if the drill bit jams, it'll try to twist the bolt out...
 
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Ahoragi said:
I did not try to extract it because i could not get a drill back there. It was either remove the head to do it on a bench or let a shop tackle it. I needed new body mounts welded in so I had the shop do both.
Click to expand...
Gotcha! For some reason I thought you wrestled with it for a little bit before taking it to a shop.
 
I thought that I would throw this out there as well.

Since the serpentine belt has been on the TJ for awhile, and it needs to come off to fix this issue anyway, I thought that I would get a new Gates belt for it. @Jerry Bransford posted this some time ago, but here it is again. Thanks for the original link, Jerry! This is a link to the Gates product lookup tool that will allow you to look up things like serpentine belts, hoses, gas caps and what not manufactured by Gates. The cool thing about this is it also gives you the OEM part number in a lot of instances. Enter your VIN, and presto, a printable list of soft parts for your fuel, cooling and engine needs specific to your TJ.

http://www.gates.com/catalogs-and-r...business-applications/vin-decoder/vin-decoder
 
If you're in search of Kroil or Aero-Kroil and can't find any in the local hardware or autoparts stores...check out your local gun shops. Both are used extensivly to clean custom rifle barrels or barrels in general.
 
Recommend the LH drill bit and quality extractors. I really like these Snap-on LH twist versions, although they might not reach in far enough if you're trying to do this through a thick flange. No need to buy an expensive set - just one or two sizes. For the exhaust manifold stud, the small extractor with 5/32" drill stamped on it would work well. Hardware store extractors are bound to fail.

Snap-on extractors.jpg
 
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Haven't pulled the trigger yet on the fix, but here's my recommendations so far:

Get the bolts and studs from the hardware store. It seems that these fasteners have been dropped by MOPAR some time ago and Dorman et. al. only have kits for the six banger. Just no love for the four angry squirrels out there.

If you have driven the TJ for any amount of time after the bolt / stud popped, do yourself a favor and do the whole enchilada. Replace all the fasteners and the intake - exhaust gasket. Guaranteed the gasket is fried. The 2.5 is notorious for popping the rear stud and to a lesser extent the front stud. Replace them all while the manifolds are off. Jeep had a fix for those two studs that was available for awhile; it was some sort of heavy slightly cupped washer. If you can find a pair of those it is supposed to fix the stud popping issue. I haven't found any in my searches yet.

Use high temp anti-seize liberally on all of the threads.

Liberally soak the fasteners down with a good penetrating oil of your choice before trying to remove them. Let them soak. This is a two day job.

Use @RaymondT 's left hand drill bit trick to remove any busted bolts / studs. Pure genius! Pilot drill the broken stud,then drill it out. Try a 1/8" pilot drill, and a 5/16" left hand drill. Run a bottoming tap into the hole to chase and clean the threads up after the broken piece is drilled out.

Replace the serpentine belt while you are in there, if it hasn't been replaced in awhile. Say more than 50,000 miles or five years. For about $35 retail, it's good cheap insurance. Keep the spare JIC. It's better than nothing on the trail. Also check the idler pulleys, might as well do them at the same time if they need it.

The total job should run less than $100, done right, and three or four hours over a weekend in your driveway. Independent shops seem to be charging about $250 or so to do the same thing in this area.
 
I've ordered a new Conti "Elite" belt for the 4-banger from Amazon.com. Claims to run quieter and cogged belts are supposed to work better around tight radius bends such as the alternator pulley. I know my current Dayco belt is quite stretched and very noisy.

http://www.thequietbelt.com/#the-art-of-silence

Also stuffing on a brand new alternator as it's starting to sing to me for the first mile or so when cold. It's original and looks very tired. Went with the 117 amp Omix-ada 17225.24 as it's specifically spec'd for my year.
 
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