mid pipe knocking

[turtlefeeder]

Okey dokey reviving thread guys. It's been a while since I sent my midpipe to ft86speed factory and they sent it to the manufacturer to check. Manufacturer told them they've inspected the pipe and found nothing defective, so they went on testing it by putting it onto their car. They again stated there was no noise. Hopefully they drove it 15-30min on highway..

anyways just got it back last week and put it on.. nothing as first so glad than a day or two after it came back quietly than the 3rd day after a drive from work to home it got loud again like the first time. Now a week since I installed it again.. anyone got any idea or free time to come inspect? It's driving me crazy here😰

[15limited]

Originally Posted by turtlefeeder

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.

That's somewhat close to where the front pipe meets your mid pipe. There is a donut gasket there however, should also be springs on this connection as well, check for those things. You should also have 5 exhaust hangers, 4 on the axle back and 1 supporting the mid pipe.

[Luftwaffel]

Pictures of all joints. Pictures of either side of piping. We're not clairvoyant.

[bfrank1972]

Who is installing/uninstalling your exhaust?

If you, then what is your procedure?

One area that can be the issue is actually the overpipe - clearance is quite narrow there and if you loosen up everything after it and move it around, it might be touching that crossmember it 's supposed to clear. Get under your car, loosen up your front pipe - move it around a bit, push up on it and secure bolt to hold it. Tighten everything up again and see how it goes.

[turtlefeeder]

Originally Posted by 15limited

That's somewhat close to where the front pipe meets your mid pipe. There is a donut gasket there however, should also be springs on this connection as well, check for those things. You should also have 5 exhaust hangers, 4 on the axle back and 1 supporting the mid pipe.

Hmm Does the donut gasket weld onto the front pipe or is it just attached in between like a regular gasket?

Originally Posted by bfrank1972

Who is installing/uninstalling your exhaust?

If you, then what is your procedure?

One area that can be the issue is actually the overpipe - clearance is quite narrow there and if you loosen up everything after it and move it around, it might be touching that crossmember it 's supposed to clear. Get under your car, loosen up your front pipe - move it around a bit, push up on it and secure bolt to hold it. Tighten everything up again and see how it goes.

I checked the connections and they seem solid also went under several times to check if it is bumping or hitting other parts but nothing that would explain the kind of knocking

[Tcoat]

Originally Posted by turtlefeeder

Hmm Does the donut gasket weld onto the front pipe or is it just attached in between like a regular gasket?





I checked the connections and they seem solid also went under several times to check if it is bumping or hitting other parts but nothing that would explain the kind of knocking

Use a bright light and look for shiny spots where the metal is hitting/rubbing. It doesn't take much of a hit to make a loud noise.

[wparsons]

Originally Posted by turtlefeeder

Hmm Does the donut gasket weld onto the front pipe or is it just attached in between like a regular gasket?

It slips over the stock front pipe, and fits snug against the stock cat back. If you're still running the stock front pipe, it was probably still there when you put the new cat back on.

That said, the noise doesn't sound like a leak at all.

[bfrank1972]

Just watched the video - you mean that sharp periodic snapping sound? That doesn't sound like rubbing to me - sounds like metal expansion or some sort of thing. Rubbing has frequency related to idle - it will sound like a buzzing.

I assume you've taken this to a shop and had them look at it? What did they say?

[turtlefeeder]

Originally Posted by wparsons

It slips over the stock front pipe, and fits snug against the stock cat back. If you're still running the stock front pipe, it was probably still there when you put the new cat back on.

That said, the noise doesn't sound like a leak at all.

Im on a full cat back, everything else is stock from 2nd cat back up to headers, I still have the stock catback with midpipe however I did not find any removable parts like the DONUT gasket maybe it could be that?

Originally Posted by bfrank1972

Just watched the video - you mean that sharp periodic snapping sound? That doesn't sound like rubbing to me - sounds like metal expansion or some sort of thing. Rubbing has frequency related to idle - it will sound like a buzzing.

I assume you've taken this to a shop and had them look at it? What did they say?

Yes it's that period snap/ knocking noise that's getting my attention, agree it wasn't a rubbing type noise, also I check for rubbing it has clearance and wasn't touching other stuff

Also yes I did take the car to a few mechanic to take a look

[15limited]

Only reason I was thinking donut gasket or lack there of would cause a build up of pressure then the joint to expand, letting exhaust gasses out then it making contact as it comes back together, but :confused: :confused:

[turtlefeeder]

Originally Posted by 15limited

Only reason I was thinking donut gasket or lack there of would cause a build up of pressure then the joint to expand, letting exhaust gasses out then it making contact as it comes back together, but :confused: :confused:

Just checked on Monday. Donut gasket still there so that's not the issue neither

[frosty288]

It's probably the overpipe tapping the subframe. It happened to me when I put on a new header, it moved the OP down a little bit - I also have a 2.5" OP. What can help is the bolt that is in the middle of the midpipe can be drilled a bit higher than it is from the factory, this will give the overpipe a little more clearance over the subframe and it shouldn't knock anymore.

Stiffer motors mounts would probably fix it too - but the cheapest and fastest way is to just move the the midpipe up a bit on the hanger.

[turtlefeeder]

Originally Posted by frosty288

It's probably the overpipe tapping the subframe. It happened to me when I put on a new header, it moved the OP down a little bit - I also have a 2.5" OP. What can help is the bolt that is in the middle of the midpipe can be drilled a bit higher than it is from the factory, this will give the overpipe a little more clearance over the subframe and it shouldn't knock anymore.

Stiffer motors mounts would probably fix it too - but the cheapest and fastest way is to just move the the midpipe up a bit on the hanger.

Hmm it knock when I'm idle after a long drive on the high way so I doubt it's hitting the subframe :/ aside from the catback the rest is stock even header.

[GsxrMe]

Delete the spring screws they factory exhaust uses. Use normal solid nut and bolts only, report back.

The factory mounts are crap but held up very well with a NA car. Once you push 300hp the factory mounts for the trans and engine turn into gue....