2016 4Runner spark plug replacement - broke emission tube stud

[cheeser]

Decided to change the plugs today with 104k on it, and didn’t have any issues on passenger side in removing the emission valve and tube from exhaust.

When doing the driver side, the stud from the exhaust manifold snapped…crap. I tried removing but not enough to grab, and also tried drilling it out, but no room to work and unable to drill as stub is slanted and could center punch…bit just wandered.

I finished the job, but now I only have one stud/nut for the driver side air tube. I used new gaskets and didn’t see any issues or hear a leak when starting it up. I used a metal zip tie on the unclamped side to help clamp down that side a bit.

Trying to determine how to move forward. As the tube is in place, I was thinking of obtaining a left hand drill bit and try drilling it out or all the way through as the tube flange can in theory keep the bit in place in the limited space.

 

[CutthroatSlam]

Decided to change the plugs today with 104k on it, and didn’t have any issues on passenger side in removing the emission valve and tube from exhaust.

When doing the driver side, the stud from the exhaust manifold snapped…crap. I tried removing but not enough to grab, and also tried drilling it out, but no room to work and unable to drill as stub is slanted and could center punch…bit just wandered.

I finished the job, but now I only have one stud/nut for the driver side air tube. I used new gaskets and didn’t see any issues or hear a leak when starting it up. I used a metal zip tie on the unclamped side to help clamp down that side a bit.

Trying to determine how to move forward. As the tube is in place, I was thinking of obtaining a left hand drill bit and try drilling it out or all the way through as the tube flange can in theory keep the bit in place in the limited space.

Pics would help here.

 

[cheeser]

Pics would help here.

I borrowed the pic from the include site link illustrating how to change plugs with the extra emission gear. It’s the lower left stud that snapped. Wish it was the passenger side as there is more room to work.

5th Gen 2014+ Spark Plug Removal (Air Injection Pump)

 

[CutthroatSlam]

I borrowed the pic from the include site link illustrating how to change plugs with the extra emission gear. It’s the lower left stud that snapped. Wish it was the passenger side as there is more room to work.

5th Gen 2014+ Spark Plug Removal (Air Injection Pump)

i just checked our 2014 and it has bolts going into the air valve to hold that pipe, whereas yours has studs with flange nuts. Regardless, you need to remove the air valve from the engine. It’s 3 nuts plus wire plugs. Be careful on the wire plugs as the wires easily pull out of the back of the plug and you’ll be throwing codes. Drill that stud and use an extractor to get it out. This is not that hard of a job.

 

[cheeser]

i just checked our 2014 and it has bolts going into the air valve to hold that pipe, whereas yours has studs with flange nuts. Regardless, you need to remove the air valve from the engine. It’s 3 nuts plus wire plugs. Be careful on the wire plugs as the wires easily pull out of the back of the plug and you’ll be throwing codes. Drill that stud and use an extractor to get it out. This is not that hard of a job.

I’ve already pulled the air valve and replaced the plugs on that side…it’s all back together.

As I noted in my original post, I tried drilling the stud, but keeps wandering off as it’s at a slant and I can’t center punch it / drill. I wanted to use a left hand bit, but they don’t come in a hex shank…I have to use a long extension on the drill.

The jobs a bit harder than expected with limited room to get in there…if it was passenger side, it would have been much easier.

I may see if I can get in there to grind down the stud a bit to flatten it, then trying to center punch again and drill.

 

[CutthroatSlam]

I’ve already pulled the air valve and replaced the plugs on that side…it’s all back together.

As I noted in my original post, I tried drilling the stud, but keeps wandering off as it’s at a slant and I can’t center punch it / drill. I wanted to use a left hand bit, but they don’t come in a hex shank…I have to use a long extension on the drill.

The jobs a bit harder than expected with limited room to get in there…if it was passenger side, it would have been much easier.

I may see if I can get in there to grind down the stud a bit to flatten it, then trying to center punch again and drill.

You’re complaining about no room to drill, so I suggested that you remove the air valve and then drill it.

 

[cheeser]

You’re complaining about no room to drill, so I suggested that you remove the air valve and then drill it.

The air valve is not the issue…it’s the fuel lines and not enough room for a straight shot down to the broken/jagged stud.

I mentioned use of a long drill extension as a workaround, but can’t with current state of stud so I need to see how to grind/flatten the jagged portion of the stud before trying again with a long bit extension.

 

[osugsxr]

The air valve is not the issue…it’s the fuel lines and not enough room for a straight shot down to the broken/jagged stud.

I mentioned use of a long drill extension as a workaround, but can’t with current state of stud so I need to see how to grind/flatten the jagged portion of the stud before trying again with a long bit extension.

rotary tool should get in there to grind it down

 

[CutthroatSlam]

The air valve is not the issue…it’s the fuel lines and not enough room for a straight shot down to the broken/jagged stud.

I mentioned use of a long drill extension as a workaround, but can’t with current state of stud so I need to see how to grind/flatten the jagged portion of the stud before trying again with a long bit extension.

Why were you removing the nuts from that end of the air tube to replace the spark plugs? Only need to remove the bolts at the air valve holding that tube, then remove the valve.

 

[cheeser]

Why were you removing the nuts from that end of the air tube to replace the spark plugs? Only need to remove the bolts at the air valve holding that tube, then remove the valve.

I thought of that later. Initial instructions showed its removal

 

[cheeser]

rotary tool should get in there to grind it down

That’s my thought…I may be able to get in via the side / fender well.

 

[CutthroatSlam]

I thought of that later. Initial instructions showed its removal

So sorry. That flex portion of the pipe allows removal of the air valve without removing the lower portion of the pipe.

Should be able to weld a nut on to the stud and get it out.

 

[Mike Beyers]

I did the same thing. I just bought one of these clamps from McMaster, milled a slot to clear the broken stud (you could grind, or even file this in). It's been in for over a year now, and works just fine. At 200k, I'll take everything apart and fix it for real. I'll take some pics tonight.


McMaster-Carr

 

[cheeser]

I did the same thing. I just bought one of these clamps from McMaster, milled a slot to clear the broken stud (you could grind, or even file this in). It's been in for over a year now, and works just fine. At 200k, I'll take everything apart and fix it for real. I'll take some pics tonight.

McMaster-Carr

Thanks for the link. I was looking for a clamp like that for a temp workaround. My metal zip tie is still holding well.

Been busy with life, but purchased a right angle drill adapter from Harbor Freight that may enable me to drill with a left twist bit. All of the 10” - 12” drill extensions only seem available for hex shank bits which only work with regular bits…havnt found left twist bits in a hex shank. I’m attempting to go that route as I would like to keep those threads, but may just have to drill through and use a bolt / nut.

I still have to get in there and cut off the broken stud to flatten (jagged stud) it so I can drill. It’s a pain working in that limited space on the drivers side though.

 

[CutthroatSlam]

Dremel with a cut off wheel should get in there.

 

[blksubykid]

I was luckily enough where the nut seized onto the stud but was able to back out the stud.

 

[cheeser]

I was unable to extract the broken stud, but was able to cut / grind down the broken stud with a Dremel, then drill through with an 1/8” and 1/4” drill with 12” extension, and then use a through bolt and nut.

 

[sprouty115]

I was unable to extract the broken stud, but was able to cut / grind down the broken stud with a Dremel, then drill through with an 1/8” and 1/4” drill with 12” extension, and then use a through bolt and nut.

Do you have a link for the extension you bought? I have the same issue on my 2018 4 Runner (both studs!). I have the studs ground flush, but I am struggling to find something to get a drill bit to reach the flange area.

Edit: So I got it sorted and just in case anyone stumbles across this thread here is what what I did...
- First, the only thing I could seem to find outside of the McMaster-Carr rod-with-a-collet (expensive) was a "drill chuck with a 1/4" hex shank". I couldn't find it locally so I ordered from Amazon and it was delivered by 10:00AM the day after I ordered it.

By 10:15AM I realized why it cost $9...the entire thing disintegrated halfway through the first hole. Fortunately, I remembered a local hardware store that somehow seems to have everything so I gave them a call and sure enough, they actually had one. It was made of steel and it did the job, though I'm not sure it will last a lifetime...

After that it was a matter of getting the drill centered and taking my time not to break anything. I ended up using the magnetic bit holder extension that I happened to have available, and that was pretty wobbly, though it did work. But if I had it to do all over again, I would order an extension that had two set screws to lock the drill chuck hex in-place (search for "Spade Bit Extention" to see what I mean).

Also, I drilled it to 1/4", which is slightly larger than the 6mm stud. And I did it in one shot, rather than start small and progressively drill it larger. I reason that it's a lot harder to break a 1/4" drill than a 1/8" drill, and I didn't want to have to deal with getting a small, broken drill out.

BTW, I didn't get an estimate of the cost to bring it to a dealer, but if I were to guess, I'm thinking it would be the better part of $1K if the manifold had to be replaced.

 

[toddsun]

I did the same thing today to the left stud.
Used a 1" clamp as a temp fix (maybe it will work just fine permanently).
Will check it pediodically to see it the clamp got loose.

 

[cheeser]

Do you have a link for the extension you bought? I have the same issue on my 2018 4 Runner (both studs!). I have the studs ground flush, but I am struggling to find something to get a drill bit to reach the flange area.

I didn’t see this for some reason, but I used a hex extension. The most difficult part was getting a dremel tool in there to cut/flatten the remaining stud portion of the stud. Once flattened and center punched, the stud was easy to drill out.

I just bought a new 4Runner and went ahead and removed these nuts on both sides, used a dab of antisieze on the stud, and reinstalled/ torqued the nuts…but of future proofing.