2016 4Runner spark plug replacement - broke emission tube stud
 

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.

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.

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.

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

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

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

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.

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.

Dremel with a cut off wheel should get in there.