Exhaust Manifold...

[81_Chevy]

well i heard an exhuast leak coming from my passenger side manifold and opened the hood and found on bolt had broken off. i took the manifold off and tried to weld a nut to it and take it off but that didnt work. so as a temp fix i just double gasket'ed it and when i went to put it back on evey bolt hole lined up except the front two, it was like they were a 1/4inch off. im thinking since i took the manifold off hot it cooled and lost shape? im not really sure. and idea whats wrong, and any idea on how to fix the broken bolt? its sticking out about little less than 1/2 inch or so?

thanks in advance!

-Nic

[bd]

Your right about the cast manifold; distortion is a common problem.  As long as it's bolted to the engine, it holds its shape.  Unbolt it and - oops!  There is actually a threaded tool available that expands between the manifold runners to help maintain alignment, but it works best in pairs when installed before removing the manifold (see image & link - http://www.summitracing.com/parts/WMR-W80663 ).  At this point, the easiest recourse is to replace the manifold - or install a cool set of new headers!!

Saturate what's left of the bolt with PB Blaster and let it sit overnight.  After about 24 hours, apply heat and PB Blaster alternately and work the stud back and forth with Vise Grips until it loosens.  Don't use excessive heat, so as not to damage the casting or valve cover seal, etc.  Be patient!  It'll come loose.

If push comes to shove, you can weld a nut to the end of the stud, or use an "easy out," which is never easy.  Heat from welding often is enough to draw penetrant in around the bolt threads, so the bolt will loosen.  But, be sure to ground the welder close to the weld to avoid vehicle electrical issues on top of the problem you already have.

[81_Chevy]

thanks for the quick reply BD! man this sucks :/ im not in the best situation for money right now to replace a manifold or get some headers (which i want to) is there any way i might be able to heat it up and get it back in place?

this whole situation is kinda my fault any way, me and my dad were planning on doing the fix next spring but i though i could tackle it in a hour or so after school. ya no lol. so yeah im not sure what to do :/

[bd]

...im not in the best situation for money right now to replace a manifold or get some headers (which i want to) is there any way i might be able to heat it up and get it back in place?...

IMO I doubt that you could get it hot enough and still be able to handle it safely.  You would have to contend with the manifold twisting, as well.  You could always try to spread the flange with the tool previously illustrated, but I think your best solution is replacement.  Still, it's $18 for two tools vs the cost of a manifold.

Dorman markets a new manifold for ~$94 ( http://www.summitracing.com/parts/RNB-674-202/ );
or ~$77 on Amazon ( http://www.amazon.com/Dorman-674-202-Exhaust-Manifold/dp/B000C123HA%3FSubscriptionId%3DAKIAJUWVMOP4RTVDXM2A%26tag%3Dstreetperform-20%26linkCode%3Dxm2%26camp%3D2025%26creative%3D165953%26creativeASIN%3DB000C123HA ).

Shop around and you may find it cheaper....  You might even find a good used one for ~$30, but take a new gasket along to make sure a used one isn't as distorted as the one you already have.  And, check that the flanges are flat and in the same plane.

[bake74]

     There is an alternative from using heat that works very well.  I have used it several times when heat did not work.  Basically it is ice in a spray can.  Does a great job of separating bolts that have been " welded " together.
     When I get to work this morning I will find out the exact name and manufacture and post it.

[bake74]

      So in case the picture does not come out.  Made by CRC, called freeze-off super penetrant.  I carry it on my work truck and use it in the field all the time.
     Guess my I-pad takes too large of pictures and I have not messed around enough to see how to re-size pics on it yet.  You have the info though, you will just have to look it up.

[bake74]

      Trying again.

[81_Chevy]

thanks bake74! i will try that!

i think im just gunna spend the extra 30$ and get a set of good headers.
i might be able to get the manifold to fit back on, but idk. like i said its not off very far so i might be able to get it.
thanks for all the quick reply's guys it really helped!

[81_Chevy]

well me and my dad deicded to go with headers, will a set of long tube headers work with my 4wd truck?

[mehunter1]

sure will!!!   I have a 79 K10 with 3" long tube headers.