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Two main problems.

Problem 1 is they keep loosening up. Not finger loose but definitely looser than the torque specs when I put them on there. I know you can't use loctite or a lock washer. I've heard about special locking nuts they make for some cars but I don't know where to get them and I don't want to wait for them to arrive in the mail. The stud goes into the head and then a nut goes on the stud to hold the manifold in place so I don't think doubling up on the nut would do anything. Any other bright ideas?

Problem 2 one of the stud holes stripped so I tapped it with the same diameter and pitch to repair it. It worked but the threads suck and the stud doesn't lose its play until it's 90% into the hole and I can see carbon escaping from this area on the gasket. So I think I need to retap one size up. But I'm concerned I'll run into issues with the larger stud being longer and not seating right. Thoughts on this?

Thanks bro

user875234
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I would say the most likely issue here is that the manifold surface is not totally flat. Somewhere near is not good enough.

A warped manifold can cause the bolts to snap. For example on my Land Rover Discovery there were 2 snapped bolts I believe were caused by the manifold warping. The new studs you can see in the picture has self locking copper nuts.

I would get it skimmed by a professional. The engineers that did mine only charged about £20 UK. Well worth the money.

HandyHowie
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