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Discussion Starter #1
It has been 1 year since install and I did notice exhaust fumes in cabin a few months ago but today while doing my yearly maint. I found that the flex part was cracked! Anyone else get this problem or is it just me?
 

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Discussion Starter #2
This is how it looks!
 

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That doesn’t look severe, but doesn’t look good and anymore heat cycling and vibrations could be catastrophic. I’d call up Joe at 2J next week and let him know. He stands behind his work.
 

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Perhaps the incorporation of an OEM style flange at the mid-pipe connection of the down pipe, one with the 3rd bolt hole to allow the use of a factory style mounting bracket, would greatly mitigate down pipe movement which precipitates the cracking of the flex portion of the down pipe.
 

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So the EXACT same thing happened to me and i posted in this forum. I was actually surprised it didn’t happen to anyone else. The reason my flex ridge cracked (the same exact one as yours) is bc the edge of the exhaust manifold is about 1/4” away from the surface of the ridge. So with vibrations and what not it ended up banging into it and cracking it.
2J initially installed mine so i let Joe know and he shipped me a new coated dp at a deep discount. Before installing than the one I bent the heat shield out of the way so it wouldn’t be close to the DP anymore. All is well now. Fingers crossed now.

I guess you can technically cut the flex section out and weld a piece in there so that you don’t have to buy a new DP.
 

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If you install your dp again and run your finger over the ridge that cracked you will feel the edge of the hear shield. Its like a razor blade sitting there. You won’t hardly be able to stick your finger in between. That’s how close it is.
 

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So the EXACT same thing happened to me and i posted in this forum. I was actually surprised it didn’t happen to anyone else. The reason my flex ridge cracked (the same exact one as yours) is bc the edge of the exhaust manifold is about 1/4” away from the surface of the ridge. So with vibrations and what not it ended up banging into it and cracking it.
2J initially installed mine so i let Joe know and he shipped me a new coated dp at a deep discount. Before installing than the one I bent the heat shield out of the way so it wouldn’t be close to the DP anymore.
As much as it sucks that you and OP had to go through this, I appreciate both of you posting this stuff. I'll definitely bend the heatshield when I get around to installing mine. Unfortunate but great FYI post!
 

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Mine is rusting right through the Ceramic coating.

38717397_1882146218532196_4551019764285177856_n.jpg
 

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Okay this is like the 5th time I've seen someone talking about this in various forums and I'm gonna say the same thing I do EVERY time:

This is not a fault of the product itself. This is a well designed downpipe. I am not "on 2J's nuts" here, ya'll need to listen up to the crap news that ya don't wanna hear cuz it does honestly suck for us as consumers:

The problem isn't the downpipe. The problem is what is connecting to the downpipe. Our OEM exhaust uses those cool spring loaded bolts and donut flanges so all 'flex' and engine movement and exhaust pipe movement gets absorbed safely in that section. So when we replace this downpipe or any of the components downstream and we DON'T have a flex pipe (which, newsflash, NONE of the exhaust products sold for the Juke have flex pipes built in, which is a MAJOR problem) there is an insane amount of vibration and movement being subjected to our exhaust pipe. And that's a LONG pipe connected to a motor that moves a LOT with all sorts of twists and torques and jazz. Since those additional bolts on the OEM downpipe have been mentioned, that is to even further drive home this point: ALL movement of exhaust system was forced through that donut flange with NO stress being placed on the oem downpipe.

One major clarification that needs to be said: the section that is cracking... where Manny's broke... where mine broke... where Joe's broke (although his rubbed on heat shield which places him in his own special category)... THAT IS NOT A FLEX PIPE. Yea, it wiggles. Yea, it flexes. But that's more of a vibration isolator by definition. A flex pipe is going to be that woven metal looking tube thing. Add one of those right after your downpipe and you won't have any problems. Has anyone done this? Bueller? Bueller? Oh, wait, that's right, *I* did and it removed all the stress from the entire exhaust system because it's now properly designed and I haven't had any problems since.

Now I'm not saying that every Juke is going to require a 'custom welded in flex pipe' in order to operate flawlessly. I'm just saying that having that flex section is PROPER EXHAUST DESIGN and if you don't... you can't be upset when the weakest link of the system (being that ribbed section on the downpipe) fails!

Also worth mentioning: Even maintaining the donut flange and spring loaded bolts with the 2J downpipe isn't a good exhaust design due to the ribbed section (still going to absorb more torque than designed). It could be argued that a better design would be to maintain the original OEM mounting bolts and bypassing the flexy section... Sure, but compatibility would shrink to 5% since everyone is doing more than JUST a downpipe and having a fully rigid exhaust system all the way back is a HORRIBLE idea and will absolutely without question catastrophically fail 100% of the time.

2J made a good product. My only fault for them is it really should be made more clear that it requires special attention to other components for reliable performance.
 

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This is why i tell people to use the oem donut squished into the second catpipe and use longer bolts with springs in them. Avoids the issue completely.


Sent from my iPhone using Tapatalk
 

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I still stand by my claim that every juke design is the same and therefore heat shield location is the same so its the heat shield cracking the pipe, not vibration. It can’t just “happen to be by coincidence” that the rib that cracked is the same EXACT location 1/4” away from a knife sharp heat shield edge. If someone else can confirm my findings of the proximity of their heatshield to dp ribs then that is THE issue.
 

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Could be the heat from the gap in the manifold. Stress from engine movement. Or a very cheap thin flex bellows and where it is placed near a bend. For 400 bucks I'd expect better. I'll take my GTM...downpipe and add a flex to it but ultimately they eventually fail.
 

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Pardon my ignorance. Is there anything special about what a downpipe endures versus the rest of the exhaust organs, that creates an environment to 'inevitably fail'?
 

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Juklear, the downpipe is pretty much the physical link between the exhaust manifold and turbo outlet to the rest of the exhaust piping. The engine is vibrating one way, the hanging exhaust is swaying another way, it sees a dramatic thermal cycle similar to the turbo and manifold, and in a place with tight clearances anything rubbing against it could act like a saw or grinder. If the whole exhaust is bolted together with straight bolts, something still has to flex when things move. Given the location and direction of the downpipe, it's the second easiest thing to bend and crack besides maybe a bolt or stud off the turbo. This is why FastReligion suggests using spring bolts or the donut gasket to provide added flex.
 

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Awesome explanation- thanks Squirt!

Juklear, the downpipe is pretty much the physical link between the exhaust manifold and turbo outlet to the rest of the exhaust piping. The engine is vibrating one way, the hanging exhaust is swaying another way, it sees a dramatic thermal cycle similar to the turbo and manifold, and in a place with tight clearances anything rubbing against it could act like a saw or grinder. If the whole exhaust is bolted together with straight bolts, something still has to flex when things move. Given the location and direction of the downpipe, it's the second easiest thing to bend and crack besides maybe a bolt or stud off the turbo. This is why FastReligion suggests using spring bolts or the donut gasket to provide added flex.
 

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Delete this post so this thread goes back into the graveyard.
 

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Discussion Starter #17
My problem was never resolved I simply Frankenstein a 8 inch flex pipe and a modded awd gtm downpipe from another user! Why bury the truth
 

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Plus they redesigned it. So Joe knew there was a problem.
 

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::facedesk::

C'mon. Soooo noob followed my instructions (although he won't admit it) and now he doesn't have problems, meanwhile Mac wants to insist that a redesigned downpipe implies fault... the fault is not the product, the fault is the consumer not understanding that poor modifications cause poor results. And also the product. And also me for repeating myself. Oh, and global warming. But mostly NOT HAVING A FLEX PIPE.
 

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Discussion Starter #20
And no mask!
 
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