Fixing a pernicious exhaust leak (help!)

[SirBrass]

Oh I love wrenching on my car, and the grime doesn't bother me at all (I just take off my button down, untucked short sleeve shirt and work in my jeans and undershirt... the tucked in undershirt also won't get snagged, so it's all good) as that's what good shop soap is for afterwards.

Btw, I installed the headers and fp/op on a lift. There's a DIY garage in the metro area that rents 5.5 ton capacity (11,000 lbs) lifts for $20/hr.

But those headers were a pain, mainly b/c of location of the runners to the bolt studs. Getting a long 14mm (as that's what's needed, not a regular 14mm) socket and wratchet in there is darn near impossible on the inner nuts. The outer nuts were not so bad, but the inner nuts on the JDL UEL were darn hard to get to. With the stock header, all header stud nuts were easily accessed (that's what she said).

Oh, and the one piece op/fp was NOT easy to get in. Extracting will be more difficult.

Now, if it was a matter of bad header gaskets or something major like that, I'd remove the header in a skinny minute and not complain. But for a leak which is hard to pin down and hard to even tell if it's still THERE due to it intermittent nature? Yeah, no. Too much work for such little improvement. I'd rather pay someone for that annoyance.

Projects and such I enjoy and want to do myself (as well as save money by doing it myself). Repairs? I'd rather pay someone for that b/c: 1) they're probably faster than I am, 2) they can determine and implement an effective solution better than I can, and 3) assuming 1 and 2 are true, I have more confidence in their repairs than I do of mine.

[SirBrass]

Glad I took it to an exhaust shop. They found the issue right away. B/c these are aftermarket flanges, they weren't mating like oem. That one leaky section was getting compressed too hard while the rest was getting proper compression.

For $15, they're replacing the gasket with a slightly thicker graphite gasket. They're also dimpling the op b/c it's hitting the engine block.

On phone I am. Therefore, if mistakes I make, Frank Oz blame you should.

[Hawaiian]

Originally Posted by SirBrass

Glad I took it to an exhaust shop. They found the issue right away. B/c these are aftermarket flanges, they weren't mating like oem. That one leaky section was getting compressed too hard while the rest was getting proper compression.

For $15, they're replacing the gasket with a slightly thicker graphite gasket. They're also dimpling the op b/c it's hitting the engine block.

On phone I am. Therefore, if mistakes I make, Frank Oz blame you should.

@mad_sb is this happening to you?

[SirBrass]

So, protip I just learned: when mating 2 aftermarket flanges together, even if they're both intended to bolt straight up to stock OEM components, don't use OEM gaskets. Go ahead and get graphite gaskets and carefully torque down the flanges. OEM gaskets were meant to seal OEM flanges. If one of your surfaces is OEM, then OEM gaskets are probably good enough even if the other surface is aftermarket.

[RavioliG]

Having the exact same problem with my Borla UEL between the header and OP.
Thanks for the insight,
I'll be taking it to a muffler shop ASAP!