Loose pre cat bolts

thekevin said:
I have been fighting a leak on my 2003 in the same spot. I tightened them to point of breaking one of the bolts so I decided to just replace them all and it's not any better.
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Just for the record , be sure it's not a header ..I had that too. Hard to see around intake , etc. ..and sounded similar .
 
Goatman said:
If you use a jamnut and then put just a small spot weld to hold them together they won't loosen up until you either grind or pop the weld. Had an exhaust manifold nut that would keep loosening until I did this.
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I like this idea . It seems radical, but sound . I really do think my maximum tightening of the bolts is barely making the pipes connect .
 
AndyG said:
Just for the record , be sure it's not a header ..I had that too. Hard to see around intake , etc. ..and sounded similar .
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I am pretty sure it's all factory. It was using these c nuts. I am thinking about getting some of that exhaust tape and putting a small piece of it around the rounded flange on the manifold side and then fitting the cat side pipe over it and tightening it up and seeing if it will seal up any of the imperfections in the fit.


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thekevin said:
I am pretty sure it's all factory. It was using these c nuts. I am thinking about getting some of that exhaust tape and putting a small piece of it around the rounded flange on the manifold side and then fitting the cat side pipe over it and tightening it up and seeing if it will seal up any of the imperfections in the fit.


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Worth a shot, keep us posted man.
 
mrblaine said:
We commonly re-tighten after a few heat cycles while the exhaust is still pretty toasty.
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This and the correct wrench (14mm offset) seems to have resolved the problem.

I think it was a combination of having gone through the heat cycles when the header was replaced and poor mechanical technique on my part.

Thanks Blaine , I'm not kissing up , but you are excellent on these. No question you know your way around them.
 
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mrblaine said:
We use the factory extruded U nuts that clip onto the exhaust manifold ears and the factory exhaust bolts. No issues with them staying tight.
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Do you have a part number or source for these?
 
mrblaine said:
Something is niggling at my brain. I think the bolts are different but I can't recall if it is head shape or thread size.
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Two years ago I needed to drop the exhaust and I had to cut the factory exhaust bolts. I replaced then with black oxide grade 8 flange bolts and nuts... the kind that are slightly deformed so they lock. I was hoping that two years later in Arizona they would remove easily but no luck, all 4 had to be cut off again.
Any advice would be well received
 
kmas0n said:
Two years ago I needed to drop the exhaust and I had to cut the factory exhaust bolts. I replaced then with black oxide grade 8 flange bolts and nuts... the kind that are slightly deformed so they lock. I was hoping that two years later in Arizona they would remove easily but no luck, all 4 had to be cut off again.
Any advice would be well received
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I don't know what you've got going on. We have never had to cut any. Our issue is the other way, they don't stay tight.
 
Get weird man. Drill a hole in the bolt and run a cotter pin. problem solved problem staying solved.
 
mrblaine said:
I don't know what you've got going on. We have never had to cut any. Our issue is the other way, they don't stay tight.
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The first time I had to cut the bolts they were heavily corroded.
Yesterday the bolts looked fine, broke loose fine, but siezed up before I could get them all the way off.
I have no idea...
Maybe wrong bolt? Black oxide grade 8
Can't use an impact on pinch bolts?
Something else I'm not thinking of
 
kmas0n said:
The first time I had to cut the bolts they were heavily corroded.
Yesterday the bolts looked fine, broke loose fine, but siezed up before I could get them all the way off.
I have no idea...
Maybe wrong bolt? Black oxide grade 8
Can't use an impact on pinch bolts?
Something else I'm not thinking of
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O booty yea that sounds like a pain. Cut those fools off get ya some new ones make sure they fit. use washers high temp lock tight. drill hole for cotter pin if keep having loosening issues. id run the gun on anything i aint scared worst case it you have to cut some stuff which you seem like you aint scared either.
 
I haven even welded nuts on bolts to make sure they stay on knowing if i ever have to remove ill have to cut them
 
I'm still fighting this on my 02, any reason I can't/shouldn't try and use a gasket on the pre-cat.
 
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