turbo noise or exhaust leak?

[JimT]

So I ended up buying a complete metric tap and die set. Figured out the pressure sensing tube that connects to the exhaust pipe is metric 12x1.0

[JimT]

Been working back and forth on multiple projects, both on the truck and around the house. Finally got around to extracting the exhaust manifold bolts. Easiest thing in the world. All 3 were broken off at or just below the surface of the head. One came out with just a flat head screw driver in a fracture groove, the other 2 came out with a 1/8" left handed drill bit. One without actually needing to drill into it, the other drilled down about an 1/8" before it bit and came out.

On the other hand, the turbo mounting studs are not coming out at all. I don't have a torch or welder so I tried doubling up a nut and that was a no go. Now I'm working on slowly drilling the broken stud out. Used one of the nuts as a centering guide for the drill bit so it's about as centered and straight as can be.

Can I get away with just replacing the broken stud, or do I need to replace all 4 as a set?

[Rawze]

Sometimes when I need to figure out the threads/pitch to something odd, I will take the screw/bolts, etc to home depot down the street and use their little screw thingy hanging on the wall, thread it in with with my fingers....lol

[hookliftpete]

Most Ace hardware stores have those as well if that is closer

[JimT]

Well, that was a pain in the...

Had to drill out the broken turbo mounting stud (the rear stud on the turbo itself). It was a slow process. got it drilled all the way through, nearly dead center and while using the extractor it snapped off again partway into the threaded hole. further attempts at extraction were futile and nearly damaged the existing threads. So as a last resort I drilled it out the remaining stud fragment to the proper size and retapped the hole. M10 1.5 Slow work but it did the trick. Reassembled and torqued.

I'll be taking her out in a couple days for a 300 mile trip empty and a 300 mile return trip with 6,000 lbs on the trailer. After tapping the new threads were not as tight as the original. I'm concerned it won't hold long term.

What are my options to repair this, should it fail? Would a helicoil work in this application with high temp studs? Is there a better solution? Are I just overly paranoid?

[Rawze]

Helicoil would work.. or a new manifold.

[tree98]

If it torqued to the proper spec it should be fine.

[JimT]

(06-07-2024 )tree98 Wrote:  If it torqued to the proper spec it should be fine.

yes, that's why I'm giving it a shot first. But, given the location, heat cycles, vibration and pressure, I'd prefer to have a plan in place should the stud fail to hold.

(06-06-2024 )Rawze Wrote:  Helicoil would work.. or a new manifold.

New manifold, no. This stud passes through the manifold and threads into the turbo.

Helicoil, great! Which one? Never used one before and a quick look through the product list I see 1084-10CN150 are the "common" 304 stainless rated up to 800 degrees F; and 1084-10TN150 are the INCONEL X750 rated up to 1000 degrees F.

Will the 304 stainless be sufficient or do I need to track down the INCONEL X750?

[Rawze]

304 stainless has always worked for me.