CGT downpipe/cat joint, need flex?

[auditude at cox.net]

Hi Huw,

I wrote within your quoted text below.

Huw Powell <audi at humanspeakers.com> wrote:
>
> > They charge me $30 to put a "fuse" in, their name for a short piece
> > of pipe welded in place.  They end up welding my downpipe to the
> > front of the cat, solid.  They removed the two flanges, metal sealing
> >  donut, and three spring-loaded bolts.  It fixed the leak sound, but
> > I don't think I'm happy with how they did it.
>
> That's called "kludge."  They are treating your car as if it has another
> year to go before the junkyard.

Right.  Actually, I went back last Friday, the next week after they did this.  I spoke to another guy, who seemed to be the boss or something.  I showed him the picture in the Bentley of the stock setup and told him what they did, and his reply was, "MY guys did that?!"

It was cool because he had a completely different attitude than the guy I set up the follow-up appointments with.  That guys said "We don't usually worry about it." regarding flexibility at the downpipe area.

This new guy agreed that, "You can't weld a pipe where there's supposed to be a spring-loaded flange!"  Those were his words!

He showed me a braided flex joint, said it was a $70 part, and told me he was going to give it to me for free because he was upset that his shop did that.

So, they put it in and it can flex there.

But now there's a new problem.  The stupid thing whistles like a supercharger or noisy turbo.  It has a sound that is almost like the pea shooter exhaust of an old Beetle.  It's mostly under load, but it's definitely new, and annoying.

After trying to weld up leaks and the noise persisting, they concluded the flex joint was a bad one.  However, that was their last one in that size, so I'm to go bad yet another Friday (tomorrow) to have a different one put in.  What an ordeal.  It's typical.  But if it is quiet after this, then I'll be happy.

> > I'm concerned that engine movement will now put stress on the exhaust
> >  manifold instead of allowing some flex at that joint.
>
> > Thanks for the reply.  The scariest part about it is I think that
> > transmission bracket is not present on my car.  Furthermore, I know
> > the drive side motor mount is torn, probably the passenger one too.
>
> So replace the motor mounts.  $50 and half an hour each?

I have the mounts actually.  My available wrenching time is focused on other things.  They are on the list for sure.  It's a balance of free time, light, lack of 105+f midday heat, and parts mostly.

> > What a PITA.  If I was going to spend bucks on the downpipe area, I
> > would swap in the 4kq EM and downpipe that I have queued.
>
> That makes the "issue" redundant.  When you install the 4kq parts, they
> will not mate to your stock cat anyway, and will require some thought
> and creativity to set up.  Thye "fuse" that as installed will go to the
> scrap metal recycler along with most of your OEM exhaust at that point.
>
> http://www.humanspeakers.com/audi/exhaust.htm

Yeah, that's some good info there.  Not looking forward to cutting the tranny boss off.

> Don't sweat it, they fixed the leak...

We'll see about that one!

Regards,

Ken