470hp etech leaking rear studs on exhaust

[Gorilla]

Hey everybody,

Today i took the turbo off as im getting it rebuilt with new bearings as it showing signs of wear and better to catch it early before you have to replace housings.

Anyways rear bottom exhaust stud was wet around it with oil so i figure time to address this BUT need some advice.  Best part is when i went to feel what sort of oil it was on my fingers i was able to unbolt the stud with my fingers which kinda made me think special thoughts ;).  Would some moron who worked on the truck not bolt it up properly or am i looking at a bigger problem?   the thread felt find when i bolted it in and no evidence of damage?

Im intending on replacing the exhaust gasket, do i need to change the bolts and all the studs while im at it?

What is the best method to stop the studs leaking oil? 

Do i need to put new bolts for the turbo too? (when i reinstall it)

Also have build up off oil on the rear of the motor, are these motors known to do sump gaskets ?

Anybody know a good place to get the bits in melbourne australia? or at least australia?

Edited March 23 by Gorilla

[Joey Mack]

All of the lower studs go into the pushrod bores. They are sealed with high temp thread sealant.  They also only screw in about 16mm. Look inside the hole to see the push rod and how close it is...  It is possible to go in too far and hit the push rod.

[Etu]

I just replaced exhaust gasket on my 2001 350 hp ETech. The original studs were threaded full length which means you have to be very careful on the lower ones to prevent hitting the push rods. I replaced with an updated stud which is threaded only as deep as required to give the 1.75” length outside the head and avoid setting too deep in the head. It’s very easy to get the 20ftlb torque while setting these updated studs.
The oil on your lower stud comes from oil in that section of the head where the push rod operates. The stud you removed  by hand apparently did not have the required Loctite 272. 

[Gorilla]

6 hours ago, Etu said:

I just replaced exhaust gasket on my 2001 350 hp ETech. The original studs were threaded full length which means you have to be very careful on the lower ones to prevent hitting the push rods. I replaced with an updated stud which is threaded only as deep as required to give the 1.75” length outside the head and avoid setting too deep in the head. It’s very easy to get the 20ftlb torque while setting these updated studs.
The oil on your lower stud comes from oil in that section of the head where the push rod operates. The stud you removed  by hand apparently did not have the required Loctite 272. 

I got some PAI studs which are treaded only part of the way but am finding getting the nuts nearly impossible after market and was wondering about using stainless lock nut (not nylon but all stainless locking bit) and a thick stainless washer as price is 1/20th of the copper nuts and from what i have read the copper is only there to stop corossion.  I am tossing up loctite 272 or Permatex 59235 high temperature thread sealant.  The copper nuts are over 40 australian dollars each from the dealer and paying 500 bucks for 12 nuts seems like highway robbery to me.

[Etu]

That is robbery. I just used the PAI 831016 Exhaust Stud kit that contained the 12 studs, 12 copper locking nuts and 6 gaskets. It was $113.75 usd. 
hopefully you can find another source. 

[Gorilla]

On 3/28/2025 at 2:01 PM, Etu said:

That is robbery. I just used the PAI 831016 Exhaust Stud kit that contained the 12 studs, 12 copper locking nuts and 6 gaskets. It was $113.75 usd. 
hopefully you can find another source. 

over here paid nearly 400 usd  or all this stuff, i must make a contact in the USA that ships to australia, here the australia tax is out of control.