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Discussion Starter · #1 ·
Hello,

I've got what looks to be a leak on the passenger side of my exhaust manifold, I haven't taken the heat shield off yet to confirm its not cracked, but indeed just a leak, however, I'd like to ask if exhaust manifold cracks are common to the specifics of a 1991 Mazda 626 GT touring Turbo, which is what I have. :)

How big of a job would it be to replace the manifold gaskets? What new hardware will I need and what besides moving the manifold back might I need to disconnect/remove? Does anyone have the removal procedures from the FSM?

Hope for a little help on this, the annoying TICK TICK TICK before the manifold warms up is getting louder and all the more annoying... :(
 

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broken stud, hla, or gasket. ive personally never heard of a cracked manifold.

i think i have a newish gasket somewhere for sale.
 

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Collapsed HLA and broken exhaust manifold studs are very common on these cars.

They sound pretty similar.. if you have an exhaust leak, it is almost certainly a broken stud.

The gaskets don't really go bad per say, but the exhaust manifold studs are 8mm in diameter and rather puny. They break if you look at them funny..
 

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Discussion Starter · #7 ·
I'm very certain its not an HLA, the sound gets louder the harder you push the gas when cold and there is a fresh bit of sooting on the left side of the exhaust manifold heat shield.

Well, In that case, the removal of the manifold is likely to break multiple studs then, and the most likely problem is a broken stud, sounds not so cool... Is there a certain suggestion or a quality replacement?

I'm defiantly not looking forward to this now, the car is my daily driver and I figured it would cost a max of $250 given the 2.5hr labor, now its looking more like a $600 repair with helicoils...

Anyone else?
 

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so do it on the weekend. fixing broken studs isnt rocket science, and you dont have to helicoil it, you can use thicker studs :shrug:
 

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Discussion Starter · #10 ·
a lot of people like to drill and retap to 10mm studs after breaking their first couple.
Do you have the length and pitch specifications, etc, for doing this?

I would like to do it myself, I've always worked on my own cars, but this time I don't quite think I'll be able to for lack of tools and assistance available this time around... :(
 

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Not sure about CA.. but here in WA, earlier this year, one of my studs broke, and I took it to local japanese specialty place.
they took care of it for flat $150 plus tax.
Another stud broke when they took the manifold, so they fixed that too, no extra charge.
 

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Yeah the surface warps too....I've had that.

While you have the manifold off, take it down to the shop and get them to machine it flat again for you.
 

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the manifold were prone to warping and having broken studs.
 

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BAH!!! Could be as simple as the stud backed out. The last couple of cars I have bought, the perv owner was saying there is a tapping from the valves/rockers. Hmmmm I smiled and noticed a touch of carbon on the heat shields and figured a broken stud. Not hard to fix. To me surprise, just needed tightening!!!
 

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BAH!!! Could be as simple as the stud backed out. The last couple of cars I have bought, the perv owner was saying there is a tapping from the valves/rockers. Hmmmm I smiled and noticed a touch of carbon on the heat shields and figured a broken stud. Not hard to fix. To me surprise, just needed tightening!!!
same here i just needed to tighten up the nuts and everything was tight. But since i was changing my turbo and im aware of this problem i replaced all the studs to slightly bigger ones and used alot of lock tight.
 

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do they make 10mm arp studs for our car

does anyone have it done i need to replace my studs too....do you guys notice alot of smoking when you studs are broken? cuz i do
 

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I tried to extract a broken stud from the bottom left of the exhaust manifold. It was really hard to get a drill in there so I ended up having to unscrew the A/C. There still wasn't enough room and I messed up the tap, so now 5 studs are intact instead of six. Better than four though, new gasket as well. Doesn't leak as bad , hah.
 
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