I am trying to figure out why the flex joint on my exhaust has gone bad twice. My Mini started making a loud resonating vibration. It was diagnosed as a loose flex joint. I replaced the header with a low miles used one. The shop told me that the new joint was good and the old joint was loose when they examined both when they were off the car.

Now the new joint is loose after one week and the noise is greater than before. I am wondering if there is something contributing to the joint getting loose. I am going to take the Mini back in to have it looked at again. I had it in yesterday and they told me that it was the flex joint again, but they didn't know why. I am wondering if the engine is rocking, due to loose mounts or something and that is causing it.

Has anyone had a problem with the flex joint on the exhaust? Did you find out what the cause was?

 

are you using the woven style ones from China?

here is what we use and they don't break..... they are used extensively on race cars .... 304 stainless with a 304stainless inner liner too

 

Hmm, maybe that is what I need. I have a stock header. It is woven. Not sure where they make it. Maybe Mini buys them from Walmart.

 

Flex joints going bad could be a sign of excessive powertrain movement. Perhaps one of your mounts is bad? Could also mean that one of your exhaust hangers is damaged. Sounds like one side of your exhaust (Catback or engine side) is moving too much and causing excessive stress on the flex joint.

 

I have yet to see a flex joint go bad ...
WOW ... you must have something REALLY moving about.

 

I am going to ad this..

To a SC pully we lift the engine ...to do a clutch we drop it.

Now the flex jouint is made to flex with normal engine movement..
Did you do either of these ?

The SC install doesnt take much but the cultch is (can be ) to much for the joint.

As a note when doing either of these mods it isn't that hard to remove the 2 bolts at the CAT ..

 

The SC and the Crank pulley were replaced before the first time the problem happened, but the problem reappeared right after replacing the header. No clutch work was done. I am planning to install engine mount bushing inserts to take up the engine movement slack.

 

I asked my really friendly / helpful exhaust guy today about this >>>

The OEM is single wire weave on the outside.

He uses a connector with double size "heat tube" with weave on the inside and outside ....
That connector costs HIM $80 to $100 !!!

He did mention that he has done a lot of MINIs

$180 a POP !