#8 Exhaust Manifold Bolts...both broken...

[bookite03]

I had a slight exhaust leak under throttle for a while now, but it was quiet enough I didn't worry about it. Now its gotten loud enough for me to track it down. Almost positive I've found it...
Drivers side rearmost cylinder (#8 I'm assuming) both bolts are broken off. So my question to the jury is can I pull the inner-fender and stand a chance at extraction with a right-angle drill/left-handed bits? Or is this one going to be more tricky?
Also a good source for new gaskets/bolts?
Thanks in advance

 

[icanfixall]

Ford or International is the only place these special interferance bolt threads are found. They are not a simple 3/8x16 thread. Getting the broken ones out is a maybe. Really any metal gasket works fine. Felpro is what I use without any problems. Get some aerokroil from kano labs and soak the broken bolts. Run the engine and let it cool down overnite several times. That stuff works wonders. The spraying and warming up and cooling down expands the meatl allowing the kroil to creep in and loosen the rusty threads.

 

[bookite03]

That's right, dont they intentionally sorta booger a couple threads to help them "lock in" the head? I'll call and see if I can locate some parts at the international dealer here in town...

I guess it boils down to if I can them out or not...lovely

 

[icanfixall]

Nope.. All the threads are cut diffrntly on the exhaust manifold bolts. Find a engine in a wrecking yard and take the bolts. Probably should take all you can easily remove. You have 6 more bolts on that side that potiencially could snap off.

 

[bookite03]

Well I guess I should of looked closer...I went for another look at the other manifold and found the last bolt on the passenger side missing, further inspection shows it must have fallen out? The threads are there and the bolt is missing!
I took another look at the two on the drivers side and realized they are also just missing as well...
TALK ABOUT DOING THE HAPPY DANCE!
No broken bolts is a relief! I was able to install 2 grade-8 3/8-16 bolts to verify the threads were OK as a test...
However, the rearmost bolt on the drivers side is a real ****** to get at. I had to abandon my project, pretty sure the gasket is still leaking.
I called the international dealer, they informed me there was an engine SN break point where they started using the Prevailing Torque bolts, before that it was a standard 3/8-16 x1 3/4" bolt. I wasnt sure on my ESN so i coukdnt verify. Are the Prevailing Torque bolts an update for all engine models? I have the last of the 6.9's in my truck...
Either way, going to order up some new gaskets and see if I can get these leaks knocked out. Just need to verify my bolts by the ESN.

 

[dgr]

Being that your bolts fell out, I would hazard a guess that there wasn't an interference thread situation going on there. You do know prevailing torque means, use once and throw away? They're also designed to be torqued to a specific amount. How's the access in there for a torque wrench?

IMHO, interference threads in a major engine component are an odd idea. It'll get it through the warranty period but exhaust bolts are notorious for breaking. Having a piece left in there that has an interference fit sounds really expensive.

I am surprised there isn't a commonly available tab washer like french locks available for this type of application. Insert bolt, tighten, bend tab, done.

 

[bookite03]

Access doesn't look too terrible if I remove the inner fender and tire. That being said, I'm not convinced the truck had interference threaded bolts to begin with....not really excited to pull 25+ yr old bolts out, but a good penetrant and patience shoud help.
Running my ESN will confirm the bolts, unless Ford was doing something different? I always assumed International built the engines, or did they just provide the parts?

 

[snicklas]

... I always assumed International built the engines, or did they just provide the parts?

Nope, IH/Navistar built the engines with the Ford specific bolt-on parts. That plant was here in Indy.... not to far from downtown. That plant was the home to all the Ford/Powerstroke/IH/Navistar engines from the 6.9IDI to the 6.4 PSD, unfortunatly that plant is now closed due to Ford building the current 6.7PSD in-house.

 

[rlb245]

that's some interesting facts I didn't no about my home state. Thank you for that history lesson young man.

 

[bookite03]

Thanks snicklas, great info there. Good to know info provided by the International dealer based on my ESN holds true.

 

[OLDBULL8]

I installed a few Banks Power packs way back in the 90's, had to remove the exhaust manifolds, can't recall why, but boke off, God knows how many bolts. What a beitch to drill out. Banks did supply new bolts with the kit, maybe you can get them from Banks. CRS, if you know what that is.

 

[cpdenton]

Maybe I had good luck the one time I took off exhaust manifolds. I was able to just break them loose, and turn them the rest of the way out by hand... THis was on a 94 turbo block, and it was th only time I took manifolds loose. I hope your luck was as good as mine.

 

[dgr]

I found this in the 6.9L update 83 A code vs 84 and later B code engines -- S/N 125553 Remove exhaust manifold locking tabs to ease servicing. I wonder if that has something to do with your prevailing torque vs. standard bolts?

 

[bookite03]

Got started on the project on my lunch break here at work. After removing the tire and inner fender there was plenty of room to get in there. All the bolts came out very easily and upon inspection they appear to be a standard 3/8 thread with a thick flat washer. The gasket was definitely blown...bought some Fel-Pro's to go back in.
I'm planning on using the standard bolts for replacement, torqued to spec with anti-seize...thinking this should work if I keep an eye on them.

BTW what's the torque value?

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[icanfixall]

That gasket you have shown is an aftermarket gasket. Don't install that kind again. Please run a smooth 10 or 12 inch single cut file over the sealing surfaces. Mostly on the cylinder that blew out. The gasket you want is thin flat soft steel. They work very well. I think the torque is 35 lbs but using new bolts I feel 40 is ok too.