Broken exhaust manifold bolt.....now what?

[megatone]

I noticed my daughters Jeep has an exhaust leak between the exhaust manifold and the cylinder head. After some looking around, I found the problem is a broken ex manifold bolt. What is the best way to remove the broken bolt? I would prefer to NOT remove the cylinder head.....there is not enough room in the engine compartment for me to use a drill. The bolt that is broken is the one closest to the firewall on the drivers side of the engine. The engine is 3.7L gas v6.

Any ideas or tips would be greatly appreciated.

 

[mx3_ryder]

Did it break off flush with cylinder head? My GMC envoy had a couple broken manifold bolts and my repair man welded a bolt to each one that was broken and they came right out. Same thing happened with my dads
f-150.

 

[twowings]

^^ best advice if there's anything there to weld to...

 

[megatone]

Yeah, it's broke off flush. I've got the manifold removed and none of the bolt shank is protruding out. I was thinking I could get some vicegrips on the busted part and twist it out, but it's a no-go.

My father said he could try to drill a hole through the fender, but I think he was joking.

 

[twowings]

can you TIG weld? that would be small enough to get in there with a torch....

 

[megatone]

I do not know how to tig weld....Is that a wire feed type of welder? My buddy Richard has a little welder that feeds the wire out of it. Actually, he has a whole bunch of welding gear (He runs a decorative wrought iron fencing company, where they are always welding up custom fencing barriers),I'll give him a call and see if he can look at the jeep and possibly give it a try.

 

[twowings]

That would be a MIG welder...good stuff...but bigger and clumsier than TIG....which involves a tiny torch and a tiny electrode....

TIG Welding:

You must be registered for see images

 

[mx3_ryder]

I would just find a trusted mechanic and leave it for them. The water jacket is close to the threaded holes so if you start drilling and tapping you may create more problems real fast. Good luck.

 

[megatone]

I just finished speaking with my buddy Richard about the problem. He came over and took a look at the situation. He said he doesn't feel comfortable about welding onto the end of the broken exhaust bolt for various reasons:

#1 is because the angle of the working area at the exhaust manifold mounting surface is kinda in a "blind spot".

#2 is because he doesn't know how the power of the welder (the electricity flowing thru the engine block) will effect the vehicles electronics.

#3 The head is made of aluminum and when the heat of the steel welding together could melt the aluminum possibly cracking it due to extreme temperature differences.

He mentioned a couple other things to consider that I had not even thought about. Anyhow, Richard may just own a wrought iron fence welding company, but he has a small machine shop also where he builds custom parts for ANYTHING, whether it's part's for a big V Twin bike or an intake manifold made from a sheet of alloy for a V8 car.....the guy's good.

So he took the exhaust manifold home with him and here's the plan:

Tomorrow he will take the exhaust manifold to his shop.......he's going to use the manifold as a template to construct a jig out of hardened steel, he's then, going to install the jig in place where the manifold should go. The jig is going to have a short tube welded to the end of it directly inline with the broken bolt, kinda like a guide tube so the drill can dig it's way straight into the broken bolt. My job tomorrow is to find a quality set of "reverse twist" drill bits (I did not know these existed) and match up the correct sized bit with the replacement exhaust manifold bolt. I am going to take that bit down to our local tool & die company and have them cut, sharpen and retemper the bit. Basically they are going to shorten the bit. In the mean time, while the bit is being dealt with, I will be busy removing the brake master cylinder and booster as well as the anti lock brake components and the steering shaft.....and hoses....and wires....and, yeah, whatever else is in the way. He is going to use a certain kind of drilling tool (I forget what he called it) but he say's it can drill holes at a 90* angle (something else I've never heard of). He said, "With any luck, the reverse twist of the drill will eventually unscrew the busted bolt on it's own and we (he) wont have to drill the entire length of the bolt. Keeping my fingers crossed.

I'll update our success or failure once it happens.

 

[mx3_ryder]

I just finished speaking with my buddy Richard about the problem. He came over and took a look at the situation. He said he doesn't feel comfortable about welding onto the end of the broken exhaust bolt for various reasons:

#1 is because the angle of the working area at the exhaust manifold mounting surface is kinda in a "blind spot".

#2 is because he doesn't know how the power of the welder (the electricity flowing thru the engine block) will effect the vehicles electronics.

#3 The head is made of aluminum and when the heat of the steel welding together could melt the aluminum possibly cracking it due to extreme temperature differences.

He mentioned a couple other things to consider that I had not even thought about. Anyhow, Richard may just own a wrought iron fence welding company, but he has a small machine shop also where he builds custom parts for ANYTHING, whether it's part's for a big V Twin bike or an intake manifold made from a sheet of alloy for a V8 car.....the guy's good.

So he took the exhaust manifold home with him and here's the plan:

Tomorrow he will take the exhaust manifold to his shop.......he's going to use the manifold as a template to construct a jig out of hardened steel, he's then, going to install the jig in place where the manifold should go. The jig is going to have a short tube welded to the end of it directly inline with the broken bolt, kinda like a guide tube so the drill can dig it's way straight into the broken bolt. My job tomorrow is to find a quality set of "reverse twist" drill bits (I did not know these existed) and match up the correct sized bit with the replacement exhaust manifold bolt. I am going to take that bit down to our local tool & die company and have them cut, sharpen and retemper the bit. Basically they are going to shorten the bit. In the mean time, while the bit is being dealt with, I will be busy removing the brake master cylinder and booster as well as the anti lock brake components and the steering shaft.....and hoses....and wires....and, yeah, whatever else is in the way. He is going to use a certain kind of drilling tool (I forget what he called it) but he say's it can drill holes at a 90* angle (something else I've never heard of). He said, "With any luck, the reverse twist of the drill will eventually unscrew the busted bolt on it's own and we (he) wont have to drill the entire length of the bolt. Keeping my fingers crossed.

I'll update our success or failure once it happens.

Hopefully success cause a new head would be in store if not. My guy could easily have that bolt extracted in an hours time without any jig. He removed 3 on my Envoy and installed the manifold for $150.00 @ $50.00 an hr. Small price to pay for a little peace of mind. You have any GM or Ford shops in the area? I ask this cause many Gm and Ford trucks are known for leaky manifolds and breaking bolts and would have experience with this job.

 

[renegade 04]

I know what a pain it is to get to, I had to replace the one exhaust manifold gasket on the drivers side. It took me and my dad about 6 hours because of the strange angles you have to remove the bolts at.

 

[megatone]

IT WORKED!!!!.....the whole set-up. The jig, the shortened drill bit, the angled drill (worm drive style). Once the jig was bolted in place of the ex manifold and the angled drill started digging into the broken bolt shank, it took all of about 3 minutes of drilling......the reverse twist motion of the drill bit did infact drill into the bolt shank approximately 1/2" and the shank unscrewed out of the hole. Worked perfectly, now tomorrow I get to spend a few hours putting the engine compartment back together.

:emoticondancer:

 

[mx3_ryder]

A job like that makes me nervous, but you do it. Great work!!

 

[twowings]

Any pics of the delicate operation?

 

[Hockeygoon]

IT WORKED!!!!.....the whole set-up. The jig, the shortened drill bit, the angled drill (worm drive style). Once the jig was bolted in place of the ex manifold and the angled drill started digging into the broken bolt shank, it all of about 3 minutes.The reverse twist motion of the drill bit did infact drill into the bolt shank approximately 1/2" and the shank unscrewed out of the hole. Worked perfectly, now tomorrow I get to spend a few hours putting the engine compartment back together.

:emoticondancer::emoticondancer:

I have only once had one come out that I tried to drill - and that was with an "easy out". Usually I end up with a new hole, threading it, then installing a larger bolt - if I'm lucky. I have tried that with tractors and small engines where I had room to use a drill.

I have tried the welding idea on a couple vehicles - it has only worked with aluminum heads. Heating up the steel with the weld and then immediately puting a wrench on it seems to make the aluminum "let go". On a cast iron block the weld usually breaks.