90,000 Mile Service Debacle - Broken Bolt

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VidereStudios

10 Year 15 Year
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Oregon
I have been working through the 90,000 mile service in my meager amount of freetime the last couple of weeks. It was going extremely well until I about had everything off. I was had taken off the passenger timing belt cover and was working on removing the connections for the driver side timing belt cover when I broke off the long bolt that helps hold on the cover and the camshaft position sensor.

I had never come across a bolt that was stuck or crossthreaded or otherwise bound up, so I didn't know what I was feeling through the socket and ratchet as I was trying to remove it. I was quite surprised when it broke off. Unfortunately, now I know the feeling of a bolt about to break.

Here is what is left in the insert in the driver's side head:

Picture1.webp

As you can see, I purchased a couple of left hand drill bits and some PB Blaster and started working on it. What a pain. Unfortunately the bit wandered even after using a center punch and smaller bit. So now I am in a bit of trouble.

I purchased a new bolt and you can see how much is stuck in the insert in the head:

Picture2.webp

Note the amount of Loctite on that new bolt...sheesh. I will be wire brushing that off and using max a drop of Loctite.

So, I guess I have three options left and I am looking for further options, input, or advice. Options are:

1. Re-orient drill path and keep going with the left hand drill bit, hoping that the bit eventually forces the bolt to start turning out. Use a combination of PB Blaster and propane torch on it.

2. Re-orient drill path and get a nice hole in it for a bolt extractor. Not an ideal solution as it is only an M8 bolt and if I break off the extractor, option 3 is the last recourse.

3. Remove head and take it into a machine shop to get the bolt out.

I have a couple of questions. I am concerned about the head gasket or any other parts near this if I decide to use my MAP torch on it. Any thoughts about getting this super hot to try to free up the bolt?

Secondly, has anyone ever got one of these inserts out? If I could get the insert out easier than the stuck bolt, that would be a nice option. However, it looks like it is pressed in to me.

Anybody have any thoughts or advice?
Picture1.webp
Picture2.webp
 
I would try to drill it out, and then use a good quality extractor, if it still wont move I'd drill to the correct size and retap the threads. That bolt is one of four that hold the timing cover on, and also retains the cam sensor wire tab I think?..Its not a super critical bolt....Sometimes the heat from drilling will loosen things up so that an extractor will work, but I'd be super careful to avoid breaking the easy out.. I would not pull the head.
 
Man that sucks! I feel your pain. I've been there and done that but not in such an odd location like you have.
I wouldn't worry too much about heat. I'd head the crap out of that area around the bolt and hope for the best. As for the drill hole not being centered, not too big of a deal. Do what you have to to get the bolt out, then you can run a tap to recut any boogered up threads.
Have you tried tapping the bolt w/ a punch? That may be enough to break some of that factory locktight crap lose.
Hope you get it out w/o having to pull the heads!
 
VidereStudios said:
2. Re-orient drill path and get a nice hole in it for a bolt extractor. Not an ideal solution as it is only an M8 bolt and if I break off the extractor, option 3 is the last recourse.
Click to expand...

I have drilled out a broken M8 with a tiny bit to make a pilot hole, and that creates some heat..... and then a LEFT handed drill bit one size larger than your pilot hole may do the trick and grab that stud. I never have any luck with extractors/EZouts.
 
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^ This.
Extractors & Ezouts are asking for trouble. In this small size they are prone to snapping off and leaving you with a real mess. Pilot drill with a decent, sharp, small [maybe 1.8"] bit. Move to a larger size & repeat until you clear out most of the broken stud. Clean out as much of the remaining steel as you can with picks and a magnet, then chase the threads with a regular tap and follow with a plug tap. Grind down the tip of your regular tap to leave just 1/8" of the tapered teeth to make a workable plug tap. Good luck with it!!
 
APKhaos said:
^ This.
Extractors & Ezouts are asking for trouble. In this small size they are prone to snapping off and leaving you with a real mess.
Click to expand...

TOTALLY agree with this statement. They have caused me more trouble than help in this type of situation. I would not recommend that approach here.

Best of luck.
 
super90 said:
TOTALLY agree with this statement. They have caused me more trouble than help in this type of situation. I would not recommend that approach here.

Best of luck.
Click to expand...

It's strange, I'm sure there's some skill level required here. I can never use one of these easy out gadgets with any luck.

My Dad however, was a Military aircraft mechanic. He could play a set of extractors and easy outs like freakin' Mozart. Those talents unfortunately were not passed onto me.
 
Don't bother with easy outs, it's fools gold in this scenario. Drill through bolt with small drill bits, then get bigger. In my experience, once you get even 1 small hole all the way through it, it will release.

Heat is a double edge sword. What you are trying to accomplish with it is to expand the metal around the bolt, thus led dining the pinch. Depending on the grade of metal in the head and in the screw, applying heat could have the reverse effect and expand the metal in the screw faster than the metal in the head, causing the bolt to be even more stuck. Long story short, if you try the heat method, make sure to nit apply the heat directly into the hole, but to apply the heat to the surrounding area of the head instead.

Good luck man, I'm sure you will get it.
 
New member.... Really enjoying the site.

Ezouts can be a real huge pain, if used wrong or choosing the wrong one/type.
I have had decent luck if you drill out most of the broke bolt. I would say with more than 50% of the bolt removed via drill (if you hit it in the center) and not risking the threads.

Using a good forged ezout, vs cheaper cast and threaded=week and brittle one.
I have both and for the really stuck bolts forged reverse threads are the way to go. Forged versions tend to be thicker.

Most importantly, you have to make sure that when using the reverse thread outs, you are applying rotational torque on the busted bolt and not any lateral (pulling up down, left or right) on the ezout. This depends on how easy it is to work on the bolt. If you start hanging off the ezout, you risk breaking it off inside the busted bolt. This is bad... Head removing bad.

Also being patient, letting some pen oil soak in, and not getting worked up about it help. Very zen like. Take your time. If you start to ham fist it, take a break, have a drink, re-think it. Based on my experience, you can feel when you are about to beak something, esp your knuckles.

I will post pics of a few different version of ezouts for your reference should you decide to go that way.

/<
 
Hey everyone, thanks for all the encouragement and ideas. I really like the idea of running the drill bit all the way through and then stepping it up in size until the broken bolt either comes out or it breaks up and can come out with a pick and magnet. I didn't really want to use the extractor option as mentioned. While I was mentally preparing myself to pull the head, I really hope it doesn't come down to that.

Well, looks like I have a game plan for the weekend. Thankfully I am a patient guy...slow and steady with lots of light and patience should see this thing out! I'll let you all know how it goes!
 
i think by the picture you posted the broken off bolt shaft is not sticking out.. if it is sticking out, you could simply dremel and philips notch in it and back it out with the philips screwdriver.. then you wouldn't have to retap.
 
Jordan345 said:
i think by the picture you posted the broken off bolt shaft is not sticking out.. if it is sticking out, you could simply dremel and philips notch in it and back it out with the philips screwdriver.. then you wouldn't have to retap.
Click to expand...

Actually there are some good ideas here.

You might be able to pull that "locating" collar off from around the broken bolt. The start soaking in PB Blaster. If you have a small torch I would heat it a "little" to draw in some PB Blaster. You can heat it up a little and as it cools spary it down a few times with the blaster at various stages of the cooling process. Let soak overnight, etc.

I've walked these out with chisels when they are sticking out. You use the chisel to catch the edge and start tapping it out couter clockwise.

Not sure cutting a groove in it will work. If it would come out with a phillips screwdrivee, it wouldn't have broke to begin with. You can also try tapping it out with a chisel after heating it to break the locktight.

This is all assuming you have some sticking out.
 
Yeah, there is nothing sticking out except for the insert. The broken bolt is about 1/16" inside the insert. Would have been lovely if it had broken outside the insert. A slot with a screwdriver would then have been an option. Or even welding on a nut or something. As it stands, the drilling out is the best option. We'll see how it goes! By the way, thanks for all the great ideas! It is much appreciated!
 
VidereStudios said:
Yeah, there is nothing sticking out except for the insert. The broken bolt is about 1/16" inside the insert. Would have been lovely if it had broken outside the insert. A slot with a screwdriver would then have been an option. Or even welding on a nut or something. As it stands, the drilling out is the best option. We'll see how it goes! By the way, thanks for all the great ideas! It is much appreciated!
Click to expand...

I don't know for sure, but the insert may pull out with a pair of pliers. Then it looks like it may be above the surface.
 
VidereStudios said:
.....I really like the idea of running the drill bit all the way through and then stepping it up in size until the broken bolt either comes out or it breaks up and can come out with a pick and magnet.
Thankfully I am a patient guy...slow and steady with lots of light and patience should see this thing out! I'll let you all know how it goes!
Click to expand...
Your head is in the right place on this. Just one more thing..
Use lots of lube when drilling. Use Tap Magic or similar cutting fluid liberally. It will help the drill cut and help keep it cool. Last thing you want is to break a drill bit in that bolt.
 
It's Out!

Sorry for the delay in my update on this broken bolt issue...family time for the Super Bowl nixed my plans for that weekend. However, I was able to spend this last Sunday working on the Lexus. My brother came over to help me with an extra pair of hands and eyes.

I am happy to say that the bolt is now out. It was a time consuming process, but we went slow and took our time. I am quite pleased with the outcome:

Bolt Out.webp

So we had left off with a hole that was started but had wandered away from the center punch hole that we previously knocked into the body of the bolt. I first had to overcome that issue. We decided on using a drill almost the size of the bolt body...3/16" to be exact. I slowly drove it in at full speed, giving it time to cool. Once we were past the hole that had wandered, we used the center punch again to located a center hole. Then I just started with my smallest left hand drill bit. Taking our time (about 15 minutes), we finally drilled through the bolt. We then drove consecutively bigger left hand bits through the bolt, hoping that it would start to turn out. Not our luck. Once we had gone through all our left hand drill bits, it was time for a decision.

We could either take the 3/16" bit and completely drill out the bolt and pick out the pieces with a pick and magnet, or take a square needle file and try to cut the bolt at some point in the threads so that it might be easier to get out with a drill bit or extractor. We decided to try the needle file first. Taking our time (another 20 minutes or so), we filed in a nice square groove on one side. My brother thought we should try the square extractor I had purchased, and I agreed. Lo and behold, it worked! The square cut profile allowed the square extractor to firmly engage the bolt without spreading the bolt like it typically would have. Boy, it was nice to see that broken bolt come out! I cleaned up the hole with a 6mm x 1.00 pitch tap, and then repeated it again with the tap shortened (thanks for that tip APKhaos).

Extractor.webp

I am super glad to have this bolt out. We refitted the cam timing sensor and the new bolt and it works just fine! It is nice to have overcome this hurdle. Now I can finish up the 90,000 mile service next weekend. Thanks all for your advice and ideas for dealing with this! :cheers:

Bolt Out.webp


Extractor.webp
 
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Very cool. I actually breathed a sigh of relief for you. Nice. Inspiring to see patience pay off.
 
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