Broken manifold stud, Advice..FML

[JOHNDERS2586]

Hey All,

So replacing the turbo, everything was going pretty smooth up until I got to the head studs for the manifold.. Only got 2 out of 5 to unbolt, 2 the stud itself came out and 1 stud I'm pretty sure was either already broke or hanging on by a thread.. As soon as i touched it it was spinning freely and sure enough its snapped off in the head.. I imagine I'm not the only one whos experienced this..

So..

For the studs that came out I assume I can buy some new studs and thread them in, maybe get from the dealer?

For the broken stud its inside the head, slightly.. such a sh%t spot to even attempt to get it out.. I'm not pro in this department. Watching a lot of videos.. This really puts a damper on things...Not really sure WTF to do.. Any advice?

 

[jay745]

You got lucky it was that one that snapped, should be able to get a small drill in there without pulling the motor, drill it out and re tap it or throw a helicoil in.

 

[Grabbit]

Let it soak in Aerokroil and try drilling it for an easy out with your fingers crossed. I had this happen on cyl #1 and ended up replacing the head. No machine shop wanted to touch it due to how far into the head it was broken off, which was further than yours.

 

[kosmaras]

As you're aware, that spot of the head looks more accessible in photos than in reality. That spot is super tough to get a drill in at the correct angle. A lot end up pulling the head or motor and doing it out of the car unless you have the patience of a saint. Best of luck.

 

[jay745]

A small die grinder with drill attachment should be able to get in there. This has happened to me a few times

 

[BudgetPhoenix]

A small die grinder with drill attachment should be able to get in there. This has happened to me a few times

The driver side one? That's the notorious one

 

[mattpowers]

Probably not recommended, but I just finished my k04 swap a few weeks ago, and I left that one undone. Previous owner had apparently snapped it when replacing the stock turbo around 52k mi. Car has 140k on it now, 50k of which were with a stage 2 tune. I haven't really run the k04 yet much, so unknown if this comes back to haunt me, but at least for the lower power output, it was totally fine without it. No exhaust leaks / issues yet, but probably too soon to tell.

I'm going to edit this and say if you have the ability, I would absolutely do what @jay745 recommended first, but as a last resort, you may be ok without it.

 

[JOHNDERS2586]

Funny I was considering this as an option (leaving it out an seeing if it leaks)...But then if i go through the efforts of getting everything back in and it does then id have to go back an take it all out again.. I know for me trying to get it out is beyond my current knowledge base, an would really be a first attempt at such a thing in a very difficult spot.., but I may attempt to drill a hole center and use an extractor.. I don't know.. I don't want to make it worse by doing something stupid either.. Just sucks.. I don't want to pay 2 grand for someone to take it out for me either.. I knew there would be risks , this to me is about worst case scenario..

 

[BudgetPhoenix]

Others have reinstalled the turbo missing a nut and have been fine. There's really not many options with that stud. If its broken off far enough most will suggest, removing head, removing engine or removing the dogbone and fans and attempting to rotate the engine far forward as possible to give you as much room as possible and a better angle to get in there.

 

[Roadrunner_GTI]

The driver side stud snapped on my car recently while reinstalling the turbo. It broke a few mm below the head surface and I was being lazy and didn’t feel like pulling the engine. I can confirm that it’s a pain but not impossible to drill out the broken stud. You’ll need a right angle drill, drill bits ranging from 1/8 to 21/64 in 1/64 increments, a mirror, and a shit ton patience. I did try to drill then extract the broken stud with both straight and spiral flute extractors, but it didn’t budge and I wasn’t going to risk breaking off an extractor. I ended up just drilling the stud out completely, then tapping for a M8x1.25 Helicoil.

There’s a decent amount of room once the cowl trim is removed

It’s important to center punch the broken stud to prevent the drill bit from walking. Doing this properly is a critical first step.

Next up is starting with a 1/8” drill bit and plenty of tapping oil. Use slow RPMs and take your time here. If you feel any resistance, reverse and clean the shavings from the bit. Also make sure the drill angle is correct, again a mirror here is key. Step up to the next 1/64 size bit and repeat until the stud is drilled completely out. The Helicoil will require drilling an oversized hole to the insert to thread into after tapping.

Here’s what the final result will be with Helicoil installed. At that point I installed a new stud proceeded with the turbo install.

Welding a nut onto the stud is another option. It involves using a flux core or mig welder to build up the stud and then placing a nut over the now protruding stud. I’m not sure this is possible with the engine still in the car, but it seems like a decent alternative to drilling. It’s also a good option if the passenger side stud breaks, because there’s very limited access to drill on that side due to the head design.

 

[king1138]

We fight broken exhaust studs like this in my shop quite often. Our best solution is to drill a hole in the middle of the broken stud, maybe 1/2 inch deep. Then fill the hole with MIG welding until a good amount of the weld bead is sticking out of the hole. Place a nut over the protruding weld, and weld the nut onto it. Allow the nut to cool a few minutes, then turn out slowly with a wrench or ratchet (no power tools!).

 

[Roadrunner_GTI]

We fight broken exhaust studs like this in my shop quite often. Our best solution is to drill a hole in the middle of the broken stud, maybe 1/2 inch deep. Then fill the hole with MIG welding until a good amount of the weld bead is sticking out of the hole. Place a nut over the protruding weld, and weld the nut onto it. Allow the nut to cool a few minutes, then turn out slowly with a wrench or ratchet (no power tools!).

Completely agree and this is the final push to get me to learn to weld. It would have made this job a lot easier. Do you flux core or mig to the broken stud?

 

[king1138]

Completely agree and this is the final push to get me to learn to weld. It would have made this job a lot easier. Do you flux core or mig to the broken stud?

We use a MIG welder, although you might be able to use flux core (we haven't tried).

 

[GIACUser]

Completely agree and this is the final push to get me to learn to weld. It would have made this job a lot easier. Do you flux core or mig to the broken stud?

Several youtube vids on the subject to guide you
Just one example

 

[Roadrunner_GTI]

Several youtube vids on the subject to guide you
Just one example

My question was more along the lines of welder setup. In theory, I know the goal is to weld a nut onto the stud. In practice though, exact welder setup makes a huge difference in whether the weld is strong enough to hold. Mig vs flux core, wire feed rates, amp settings, gas flow settings, wire type, etc are more the questions I have.