Exhaust Manifold Replacement

[54bobby]

so, my new mani and front pipe arrived. now, i need to deal with 2 broken mani bolts. the one has just a little bit protruding but the rear seems to b broken off flush. fingers crosed i don't have to pull the head. i'm not doing it myself cause it's a little more than i can handle in the driveway only being a shade tree guy. i do have an experianced guy doing it who will work with me financially if the worst case scenario pops up. on an 87 2.5, is there room to get a drill on the front and rear bolts to drill/easy out them?

[JeepComanche89]

First of all I'm a 4.0 guy, so I can't help you there. However I do not think you are going to have much luck with an easy out. I tried that when one of my manifold bolts broke, luckily it was in the front, but it did not work. I ended up putting in whats called a helicoil. Its a coil type thing, that threads into a tapped hole, but has threads inside so you can thread a bolt into its self. I probably didn't explain that very well, but look it up if you don't already know what it is. To put in in you have to drill out old bolt, drill out that hole, tap that hole, insert helicoil, and then your good to go. You can buy a good helicoil kit from a good parts store and it will have everything you need to make multiple helicoils that size. Tell the parts guy what size the original bolt was, and they should be able to get you the right size helicoil. 

[Biotex]

I am not a fan of EZ outs. More times than not, they break off and you are in worse trouble then.   What I would try first on the one sticking out a little bit, I would take a nut that fits over the nub and weld inside the nut to attach it. The heat from welding helps to break loose the rusted threads, and you can usually remove that broken bolt.

 

The one that is flush, you should center punch it and drill it out with a LEFT handed drill bit. Start small and get bigger in steps. The heat from drilling, and the left hand bit usually backs out the broken bolt without needing to use an ez-out.

If you mess up the threads, then you will need a Helicoil to repair them.

 

Use anti-sieze compound when you reinstall new bolts.

[54bobby]

does anybody know off hand the bolt size for the manifold bolts? just so i can start tracking down the helicoil kit if needed. i've heard of them before and do have a little experiance using a similar kit for my bmw oil drain pan hole. something called (time sert) system.

[mjeff87]

3/8 x 16

 

Been there, done that.....several times ;)

 

Jeff

[Exgrayxj]

IF you are lucky, and have the room, the offending broken bolt can be burned out of the head with a torch.

It won't hurt the cast iron, maybe just a little cleanup with a tap, but it won't melt the cast iron.

On the one with a little sticking out, just heating it then vise grips might do it.

I didn't just hear this, I have done it.

I didn't believe at first, though, when I was told it.