mid pipe knocking
 

hey guys I got an issue and need your help/experience!!

so I recently upgrade to a mxp sp exhaust from ft86speedfactory and it was good for the first day didn't really go on freeway or long drive, a few days last week it started making a knocking noise after a drive on the freeway/highway from work, I came to an exit and notice a loud knocking noise decending from loud (can hear with music on) to soft (like popping from hot manifold/header) than it dissappear and all this was under like 20second. now I notice it anytime. I've contacted ft86speedfactory and they said it may be a leak and ask me to check my bolts if they're tighten and connect correctly. so I jacked the car and went under.. didn't see issue or couldn't find one. so I took it to my uncles shop, he put it on in a lift and visually inspect, told me it's correctly installed ,even tried to tighten the bolts more but it didnt budge, he also said it's new and need some time to settle (if it's true it needs time let me know) but have you guy got this problem or can think of something else I might of missed?

thanks in advance

Not uncommon to exhaust slap the bottom of the car/heat shields and knock around. Have seen this a lot with eBay exhaust. I know some people have had problems with the ft86speedfactory headers hitting the underpan and knocking but haven't read anything about mid pipes knocking yet. Take it off and inspect it to see if you can see where it would be hitting something or evidence on the mid pipe itself of rubbing. Very well could be something else and not the mid pipe could be coincidence... Happy hunting

Totaled, so whens the part out??











Are you sure that is what is making the sound? Install the stock exhaust and see if the sound goes away. Exhaust doesn't make a knocking sound as far as I know

Both are BS answers.

Do you hear a knocking noise or do you feel it? There's nothing special about exhaust systems. If you only changed the catback and nothing else, you have two sources of noise:

1) exhaust leak from either gasket, or premature failure of welds (I've seen it plenty of times before on brand new exhausts)
2) exhaust is making contact with the car somewhere, either from poor positioning of exhaust, bad hanger placement (bad jig or weld), or broken hanger causing excessive movement

@turtlefeeder ........I'll buy into this theory.

I suggest you put the car back up on the rack, figure out which direction the torqued engine pushes the exhaust pieces, find the potential contact point(s) with something else under the car ......... and here comes the humfrz redneck fix ....... use a crow bar and force the exhaust piece away from the contact point(s) and "wire it over".

:)


humfrz

yes the exhaust it knocking around mid pipe area I open the door and check when it easy knocking loudly and it seem to come from right under the center console in the middle of the car. there are no gaskets it is tightened by clamp with nuts. on inspection there are no contact with other parts. it Seem to be inside the pipe. it goes silent quickly than only notice it after long highway drive

deal with it for a week and then get the car up and look for where its making contact. adjust it to correct

The third, and most remote possibility, is that the exhaust has already broken inside the resonator and you have a defective exhaust, hence the knocking noise.

-alex

Hangers are solid they hardly move even if I try to wiggle the exhausts, any advice on how to check for leaks? Because just looking at it I see none

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Look - for soot at a joint or connection

Listen - for a pspptttt sound

Feel - with a wet rag (listen for a sound)

Still, I'll betcha it's a pipe banging on something .....;)


humfrz

Thanks I'll look into that on my days off

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Check all around your driveshaft to be sure you have enough clearance and that nothing is shifting. Is the knocking rhythmic or random?

The knock it starts loud slowly, as it gets more quiet the knocking becomes faster than silent

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Alright bringing back thread.

Contact ft86speedfactory again with a video of the knock they could not figure out the issue so they ask me to bring it to another shop/mechanic to diagnose again, which I will do as soon as I can, but here's a video if any knows .. LET ME KNOW LOL driving me nuts and I feel like my car is rubbish and Cheap 😅
[ame]https://m.youtube.com/watch?v=HvxhMLOaoDM[/ame]

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