Broken exhaust stud removal

[JeffKeryk]

Impressive work @JHZR2.

 

[Sam_Julier]

@JHZR2 Thank you for your time and efforts to post this project. I learned so much!

Sam

 

[The_Eric]

Thanks!

I have both a stainless steel nd a graphite gasket for the turbo flange. Should I use any product on the surface?

Something like the copper gasket spray?

https://www.permatex.com/products/g...opper-spray-a-gasket-high-temp-sealant-12-oz/

It says, “Permatex Copper Spray-A-Gasket Hi-Temp Sealant is a fast-drying, metallic copper sealant that helps dissipate heat, preventing gasket burnout and improving heat transfer. This high temperature sealant spray sealant instantly and fills hot spots and surface imperfections and resists all types of automotive fluids.”

I think I had gasket burnout or some other form of erosion which is what caused the leak.

The product says it’s only good for 500F but also says it’s for exhaust manifold gaskets.

The only sealant that I've ever used is Taber's Flox-Ex - it's some really good stuff. That said with such a nice flat finish, you likely won't need any sealant. And FWIW I would use the stainless steel gasket.

 

[JHZR2]

I have a few parallel threads. Each was related to a skill I thought was unique enough to justify a thread for future reference.

I will post back here once the helicoil is done.

But in the meantime im going to lock this and reopen the other one here:

Thread 'Repairing damaged manifold stud and smoothing surface'

Apr 25, 2026

This is a follow up to a few related threads, as I think this is a specific skill and technique so best left separate to address. The manifold on my 1991 MB300D has a bit of erosion at the turbo interface.

The manifold is cast iron. The studs I believe are stainless. All the hardware came apart very nicely after 230k miles. Thing is, I cannot get the four studs out.

Two I can see on the backside, two are blind holes.

I’ve tried months of penetrating oil. I’ve tried double nutting, which just spun. I’ve even just tried inductive heating, but I couldnt get the stud...

• JHZR2
• Replies: 39
• Forum: Mechanical/Maintenance Forum

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