Stubborn bolt on exhaust manifold

Got 7 of the 8 bolts loose,the last one won't budge,Rather than breaking it off at the head I thought of drilling the head of the bolt and removing that part of the bolt.Then remove the manifold and try penetrating oil on the bolt.If that doesn't work will heating that area of the head to get wax to seep in warp or ruin the head.It is still bolted to the block.Any suggestions.

 

Get out the torch! Works EVERY time! even before drilling just heat up the threaded area around the bolt and should expand the metal enough the break the bolt free.

 

Is it possible to reinstall the other bolts with anti-seize, then fire up the engine, warm it up, and break the stubborn bolt loose?

 

No,the engine is out of the car

 

Go right to the torch. Get the manifold cherry red around the bolt and put a vise-grip on the bolt and it should back out without too much effort just like Menges said. I do it all the time and it's never failed me yet. When it starts to turn out, you should hear a squeeking noise. That means your doing it right.

 

Thanks for the help

 

hey COUP MAN...it doesn't have to come out every time, yes it should but. but to be truthful it's the best option you have. good luck my friend...POP.

 

Everyone above are correct heat that baby up and after it cools abit spin it out if it breaks the manifold will come of and then do the heat again and use vice grips, or slide a nut over the bolt and weld it so you can use a socket and remove it.

 

Hey dude.....go withthe flow.....not agianst it........engines out, ger your 4 1/2 grinder.....grind the head off.....slide off the exhaust manifold.....then you'll have a few inches if stud to work with.....heat that puppy up and put a small pipewrench on it.....and out shell come.....

That way....you'll have something to work with.......sometimes....if you just go to heatin' and twistin', sometimes it'll spin off even with the head......and then you run the risk screwing the head up if your not experienced with getting broken bolts out....

 

That's what I was thinking,just wanted to make sure the heat wouldn't warp or crack the head.Thanks again Guys

 

The "blue wrench" is almost a guarantee on removing frozen studs. Keep the heat local to the bolt head, cast iron is a poor conductor of heat anyway so you won't hurt anything else.

Bob

 

Just did the procedure on my Thunderbird cast iron manifolds. Bolt came right out. But be careful. Those babies stay hot for a very long time. Don't burn yourself like I did.

 

cut the head off and get the manifold out of the way. pipe wrench or vice grips with some heat will get it out.