Just twisted off an intake manifold bolt!!!

[ubtripn]

Hi Everyone,

So I was leaking oil out of the intake mainfold bolts on my 68's 350. I was taking each one out one at a time and applying Permutex high temp black silicone. When I got to the second to the last bolt on the passenger side closest to the distributor the head - the bolt just twisted off. 97& of the stud is intact in the hole, just the head of the bolt and 2 turns of threads came off. I know that I will have to deal with this later on but can I just leave the stud in since it is siezed and maybe put a little JB Weld on top of the stud? Then I could drill it out later during a rebuild. It seems to me that the worst that could happen would be to keep leaking a small amount of oil in that spot but I am a novice so what am I facing? Will the stud leak more now? Is the whole manifold not going to be sealed in the back now? Thanks for any help you can provide.

[Alex Hayley]

Ooops....Lucky that you will have a decent amount of the stud left when you pull the intake. I would not use JB Weld. I would seal it with a softer sealant and keep an eye on oil leaking.

[60ratrod]

well if its the second from last bolt in the back on the intake then you will be leaking coolant because you won't have the pressure from the bolt to keep the seal tight and secure and you can leak coolant into the motor. what i would do is go to either napa or the hardware store and get an easy out/extractor. i prefer the square style easy out/extractor cause to me they seem to bite the metal better.

[pat 70/71]

Can you grip the shaft of the bolt? you need to get it out of there. center punch it drill it out ( small drill) and use an easyout if you don't feel you can do this, talk to a buddy who has done it. Everyone that plays with these trucks has run into this at one time. hope this helps you. cheers, Pat

[Sammy]

Yes, I agree. You might be doing a rebuild next week if coolant leaks into the pan and you throw a rod or a main bearing. Be safe and get that torqued properly. Torgue those bolts in proper sequence.

[Sinister]

If you have a welder, I'd weld a nut to it.

[Duncan and son]

Originally Posted by Sinister

If you have a welder, I'd weld a nut to it.

x2

[ubtripn]

All great ideas, thanks guys. I was hoping that since it was second from last that the other bolts might keep enough pressure on the manifold. There is coolant under there as well as oil? Are they in separate channels so they don't mix?

[60ratrod]

there actually isn't any oil going through the intake. the oil is either coming from the lifter valley or from the valve covers. the oil coming from the lifter valley is either fumes from the heated oil or oil splash from the from the lifters them self. coolant on the other hand is running through the front of the intake and the rear just blocks off the rear passages of the cylinder heads. sounds like you might need new intake gaskets

[ubtripn]

To be more specific the head of the bolt plus a little bit of the stud broke off so there is actually a slight dimple that goes downward there now. Is ther a chance of the seal keeping on the intake manifold overall?

[71swb4x4]

No, it won't seal. Best case scenario it makes a big mess on the intake. Worst case scenario the coolant goes into the lifter valley, mixes with oil, and you blow the motor. Pull the intake, get the stud out, and put it everything together.

[cdowns]

sillycone is a poor thread sealant// i prefer using the teflon oaste stuff they sell as "thread sealant" in autoparts stores

[ubtripn]

ok, thanks, I guess since it was kind of towards the center I was practicing wishful thinking. Thanks for the advice. I'm taking it.

[Sillyoldman]

Dont use an easy out. Your'e screwed when they break because they wont drill out. It will break,trust me. Saturate it with a penetrating oil for a couple days. Then use a reverse drill bit and heat. It will free up just don't be in a hurry.

[60ratrod]

Originally Posted by Sillyoldman

Dont use an easy out. Your'e screwed when they break because they wont drill out. It will break,trust me. Saturate it with a penetrating oil for a couple days. Then use a reverse drill bit and heat. It will free up just don't be in a hurry.

i've used easy outs before and never had one break, but then again i don't think the bolts were torqued

[bigsnookmaster]

If a piece of the bolt is sticking out, I'd take the manifold off and try to grab it with a GOOD pair of visegrips, or weld the nut to it.You can always put some heat to it also.Good luck

[El Jay]

Originally Posted by Sillyoldman

Dont use an easy out. Your'e screwed when they break because they wont drill out. It will break,trust me. Saturate it with a penetrating oil for a couple days. Then use a reverse drill bit and heat. It will free up just don't be in a hurry.

Good advice.

To add a bit to it, I'd have everything set up & ready to go; bolt center punched & the drill loaded & ready to go.
After heating the bolt, I'd hit it with a candle to get some wax down into the threads & then start drilling with the reverse twist drill. The tip of the bolt is a little harder than the rest and when the drill hits the end, it will try to bind & back the bolt out.
If this doesn't work, then you already have a hole drilled for your E-Z out.

[johnechi]

Originally Posted by El Jay

Good advice.

To add a bit to it, I'd have everything set up & ready to go; bolt center punched & the drill loaded & ready to go.
After heating the bolt, I'd hit it with a candle to get some wax down into the threads & then start drilling with the reverse twist drill. The tip of the bolt is a little harder than the rest and when the drill hits the end, it will try to bind & back the bolt out.
If this doesn't work, then you already have a hole drilled for your E-Z out.

And if that didn't work just weld a washer onto the broken bolt, then weld a nut to it. Reheat with a mapp gas torch and dab some paraffin on it (candle), and then it SHOULD come out. We used to do this with broken head bolts also.

[bigsnookmaster]

Once you have the shoulder of the bolt exposed, smack it with a hammer a couple of times, this can work wonders also, but don't kill it when you hit it. I would bet once you have the manifold off, it won't be that hard to get the bolt out.

[propanemudtruck]

Originally Posted by bigsnookmaster

Once you have the shoulder of the bolt exposed, smack it with a hammer a couple of times, this can work wonders also, but don't kill it when you hit it. I would bet once you have the manifold off, it won't be that hard to get the bolt out.

Reading the replys to this post I was looking for the hammer trick. Shocking the threads will do wonders for sure! Every brake bleeder I every open gets tapped with a ball peen before I put my line wrench on it, same for broken bolts... If the hammer doesn't work, then I go to the blue hot wrench

[68 TT]

Originally Posted by El Jay

Good advice.

To add a bit to it, I'd have everything set up & ready to go; bolt center punched & the drill loaded & ready to go.
After heating the bolt, I'd hit it with a candle to get some wax down into the threads & then start drilling with the reverse twist drill. The tip of the bolt is a little harder than the rest and when the drill hits the end, it will try to bind & back the bolt out.
If this doesn't work, then you already have a hole drilled for your E-Z out.

I was a machinist in the air force for 13 years and removed on average 20 broken or damaged fasteners per day.

Make sure you use a die grinder with a ball end carbide cutter on the head of the broken off bolt. The irregular surface will damage your drill bit and/or make it walk to the side damaging the intake.

Make sure you are drilling perfectly parallel with the center line of the bolt with the left hand drill bit or it will break the drill bit when the bolt starts to come out.

A 1/4" left hand drill bit will work well on the 3/8" intake bolts.

If you have a hammer drill use it. The shock will help break the fastener loose.

[ubtripn]

I am going to do just that tomorrow because with the manifold off the stem will be sticking up.

One physics questions that keeps bugging me though, if the block has threads and the intake manifold has threads and the bolt was fully torqued and when it was set to be removed, just the head of the bolt came off. Then what you have left is a threaded stem inside both the intake manifold and the block, how could the intake manifold not stay sealed? Wouldn't that stem have to unthread to create a gap? If it is siezed in place I just don't see how it could rotate which it seems would be required to loosen the tension of the intake manifold to the head? If only the intake manifold portion of the stem had threads then I could see but the block does too?

At any rate, I will pull the manifold tommorow but if anybody can answer that question it would really help put my mind to rest. thx

[loosecannonzs]

The intake isn't threaded, only the heads.

[ubtripn]

Wow-you guys are great, thanks for all of the advice.

[71tahoe]

You should also investigate why there is enough crankcase pressure to push oil out the intake bolt holes. Make sure your PVC system is working.