Broken Intake Bolt

onefstsnake

New Member
Nov 25, 2005
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Northern VA
Well one of my intake bolts sheared off into the head.

I bought a bolt extractor but the broken bolt split and is now stuck deep in the head.

Its the passenger front bolt.

Im wondering if I can just leave that broken piece in there when I put the new intake on and leave the new bolt out???

Either that or I need to drill and tap the head to accept a 3/8" bolt...
 
Pull the head and take it to a machine shop. The head bolts are unlikely to break since they are much stronger than the manifold bolts.

Leaving the broken bolt in there will cause a leak. You could get water in the oil. That will kill your bearing in short order.
 
This saved my ass once, so maybe it will work for you. I broke a bolt down deep once and I used a small punch and a hammer and painstakingly chisled enough of a groove that I was able to use heat and a flat head screwdriver to work it out. I don't know without looking at the car or seeing a pic of the spot but it might be worth a try.
 
Definately don't just leave it out, you'll be in for all kinds of trouble then just like jrichker said. Also, you won't want to drill and tap it to a larger size because torque will no longer be even across the intake. I'd definately try Robs96 idea before taking the head off, but you must be careful not to screw up the threads.
 
onefstsnake said:
Well one of my intake bolts sheared off into the head.

I bought a bolt extractor but the broken bolt split and is now stuck deep in the head.

Its the passenger front bolt.

Im wondering if I can just leave that broken piece in there when I put the new intake on and leave the new bolt out???

Either that or I need to drill and tap the head to accept a 3/8" bolt...


The intake bolt`s are 5/16".
If you leave that front passenger side bolt out,you will likely have coolant leakage.
 
Can you remove the intake and use heat and some vise grips to remove it? You should still have somewhat of a stud left after taking the manifold off. This maybe the only thing left to try. I'm not too sure about the JB weld idea but hey, if it works let us know. How did you shear the bolt head anyway?
 
This happened to me on two different cars. Both the exact same bolt. Passenger side front. I repaired both with heliocoils without removing the head. Remove the intake. Stuff some rags in the lifter valley under the seized bolt and tape off your ports beside the bolt. Centerpunch the seized bolt and start with a small bit to make a pilot hole and then go bigger. Gotta make absolutely sure you stay straight when drilling. What I did for the final drill size was I temporarily reinstalled the intake manifold and made like a spacer that fit in the manifold bolt hole and made the bit fit tight through the spacer to keep the bit completely centered and straight. Then tap and thread the heliocoil, shopvac everything out real good and your done. Worked great for me in both cases.
 
EMW150 said:
This happened to me on two different cars. Both the exact same bolt. Passenger side front. I repaired both with heliocoils without removing the head. Remove the intake. Stuff some rags in the lifter valley under the seized bolt and tape off your ports beside the bolt. Centerpunch the seized bolt and start with a small bit to make a pilot hole and then go bigger. Gotta make absolutely sure you stay straight when drilling. What I did for the final drill size was I temporarily reinstalled the intake manifold and made like a spacer that fit in the manifold bolt hole and made the bit fit tight through the spacer to keep the bit completely centered and straight. Then tap and thread the heliocoil, shopvac everything out real good and your done. Worked great for me in both cases.
Finally, it's about time someone suggested the way that a shop would handle the problem! :)

I LOVE reading posts about slotting the bolt and welding to the bolt. IMHO, if slotting the bolt then allows you to take it out, get a clue and remove the bolt in the correct direction in the first place. :) Welding is often NOT an option. And, I would NEVER suggest a newbie welder try it.

Why remove the head? That's a ton of work! Get 2 rolls of paper towels, STUFF every hole. Put cloth towels over the paper towels, drill the bolt (use a vacuum cleaner near the drill if you have an assistant), and put in a heli-coil. A heli-coil is more than strong enough to hold down the intake!

See:
Heli-Coil Install. Olds Quad 4 head example.
http://www.veryuseful.com/GM/tech/heliCoilInstall/

You can see that I used ~$1 of Duct Tape to keep the shavings out of the head. Ohhhh, a whole $1 of Duct Tape! I guess using $1 worth of duct tape is too expensive and too much work for some people. ;)
 
I did the same thing. Those bolts are suseptible to breaking since after time coolant leaks by them and corrodes them and they snap. It would be a good idea to coat the corner bolts of the intake in silicone when you replace them. Another option for getting the bolt out is to weld a nut to it and use a wrench to get the bolt out. Welding to a broken bolt puts huge heat through the bolt and it breaks up rust or whatever is causing it to be stuck. I have done this many times and they always come out.
 
Broke the same bolt, doesn't appear to be uncommon. After unsuccessfully trying various chemicals and extractors I ended pulling the head off and drilling the bolt out from the backside. The other end of the bolt is concave so a drill bit won't be dancing around. The rough edge of the broken end really didn't allow starting to drill it out from the top side.

Start with a very small drill bit, and progressively step up to larger drill bit sizes. As you get closer to the edge, you will be able pull the remains of the bolt with a small needle nose pliers. You might need a small punch to try to get the remains loose. Tap it lightly as if you were trying to turn it. Or try using a flathead screwdriver to try to budge it. Using the needle nose to bend the bolt threads way from the head will also help as you get close to final extraction.

Run a thread chaser through to clean up the threads in the head. Buy a new bolt. If you're worried about thread engagement, you might be able to use a longer one at that position. Use a little anti-sieze.