Snapped exhaust manifold stud, Also snapped EZ Out

[dom14]

Got it sorted, decided to go with the expensive way out and get a professional out to remove the stud, wasnt cheap but the job is done cleanly with no helicoil needed. I wont be using those left hand spiral type of EZ outs again thats for sure!

Thanks everyone for your help, i'll be alot more careful when it comes to removing my next broken stud.

Any thing i should know when putting new studs back in? i know the torque setting for the nut when the manifold goes on, but is there one for the stud?

Not per say. You can use thread sealant to ensure the stud never moves on it's own.
I used thread sealant with mine 'cos the nut can sort of weld onto the stud over time due to heat and rust and come out
with the stud when try to undo it. But, usualy if you tighten the stud all the way in, it should be fine.
The thread sealant I used is the type that can be melted when the stud is heated to a certain temperatue that is well below the melting or deforming temperature of aluminium alloy cylinder head, so it won't cause any issues in the future if I have to take the stud out.

How did the professional get the broken stud(and the broken ez out bit in it) out?!

[DickieO]

He was able to grind away enough around the EZ out till he was able to remove it, then he re-drilled it and removed the stud using probably a better quality ez out.

FYI, the EZ out I used and snapped in the stud were the Sutton brand, 85 bucks for 5 drill bits and 5 ez outs, i started on #3 with the 3mm hole (figured i could go to #4 if required), drilled more than deep enough, twisted in nice and straight and it snapped with what i felt was considerable less force than expected it would.

[dom14]

He was able to grind away enough around the EZ out till he was able to remove it, then he re-drilled it and removed the stud using probably a better quality ez out.

FYI, the EZ out I used and snapped in the stud were the Sutton brand, 85 bucks for 5 drill bits and 5 ez outs, i started on #3 with the 3mm hole (figured i could go to #4 if required), drilled more than deep enough, twisted in nice and straight and it snapped with what i felt was considerable less force than expected it would.

Yeah, I wouldn't use them to remove any broken studs in high heat spots like the exhaust. I would use a matching size drill bit to drill through the broken stud carefully and then re-tap the thread.(That's what I did with the broken studs on my exhaust flange & manifold studs)

Make sure to use studs for the exhaust manifold & the flange. Never use bolts. It will be matter of time they deteriorate from the heat and eventually break when you try to undo the bolt. Half of my exhaust manifold were bolts. I replaced all of them with studs.

[UncleFrosty]

FWIW, I got some advice on this from someone who has to deal with this situation almost daily.
The advice - there is no replacement for preparation. Takes days if you have the time available. Heat & oil. Heat & oil. Heat & oil.
Then, and only then...
If part of stud outside hole, by far the highest success rate for him is to weld a nut onto it.
If stud broken inside hole, build up with weld (with lots of care not to weld block/base material) then nut method as above.
If not an option, then resort to easy-outs (or similar)
But there's no replacement for taking the time to prep it.

Did I mention prepping was important???

[dom14]

FWIW, I got some advice on this from someone who has to deal with this situation almost daily.
The advice - there is no replacement for preparation. Takes days if you have the time available. Heat & oil. Heat & oil. Heat & oil.
Then, and only then...
If part of stud outside hole, by far the highest success rate for him is to weld a nut onto it.
If stud broken inside hole, build up with weld (with lots of care not to weld block/base material) then nut method as above.
If not an option, then resort to easy-outs (or similar)
But there's no replacement for taking the time to prep it.

Did I mention prepping was important???

Yeah, that's what I did to get one of the studs out of the exhaust manifold flange.
The stud was pretty much welded to the manifold flange.

http://www.nissanpatrol.com.au/forum...flange-surface

[DickieO]

Ordered some new studs and nuts, arrived today for a busy weekend to come. Wont be using those type of EZ outs again thats for sure @dom14.

I know what i'll be doing next time, lots or preparation, plenty of heat and oil, and probably some more preparation hahahah thanks Frosty,

What are the ZD30 heads made of? Welding the stud to the head was one of my main concerns cause it was recessed into the head.

[dom14]

Ordered some new studs and nuts, arrived today for a busy weekend to come. Wont be using those type of EZ outs again thats for sure @dom14.

I know what i'll be doing next time, lots or preparation, plenty of heat and oil, and probably some more preparation hahahah thanks Frosty,

What are the ZD30 heads made of? Welding the stud to the head was one of my main concerns cause it was recessed into the head.

I think it's the structural fatigue from heat over time as well as rust that cause them to break.

For the flange, I used stainless steel studs to prevent the rust issue.
I basically bought a single long stainless steel bolt from Bunnings and cut it to make three studs for the flange.
Pretty economical and effective way to do it. Manifold studs didn't need to be stainless steel 'cos sometime soon I will have to recondition cylinder head.