S3 diesel - problem where exhaust manifold meets downpipe?

Hi all,

According to a friend, it's a typical problem for [series 3 2.25l diesel]
landies like mine - the connection between the exhaust manifold and the
downpipe is knackered. Much of the exhaust never gets as far as the
tailpipe, and the thing makes the most dreadful racket, especially early in
the morning when the neighbours were asleep. Feels like I've losing power
too, something to do with backpressure (?)

I've replaced the rest of the exhaust (woohoo! my first exhaust change) but
understand that the downpipe is particularly tricky as it will probably mean
changing the manifold too, and there's lots of stuff in the way.

Does anyone have any suggestions for how I can best bandage this joint? I've
packed it with exhaust repair gunk and put a jubilee clip around it to hold
it all in but it never seems to hold for more than a few days before it's
blown a gap out the side again.

Any advice appreciated.

Thanks,

h

On Thu, 19 May 2005 22:47:06 GMT, "h" <h@@at@@howiem.com> wrote:

>Hi all,
>
>According to a friend, it's a typical problem for [series 3 2.25l diesel]
>landies like mine - the connection between the exhaust manifold and the
>downpipe is knackered. Much of the exhaust never gets as far as the
>tailpipe, and the thing makes the most dreadful racket, especially early in
>the morning when the neighbours were asleep. Feels like I've losing power
>too, something to do with backpressure (?)
>
>I've replaced the rest of the exhaust (woohoo! my first exhaust change) but
>understand that the downpipe is particularly tricky as it will probably mean
>changing the manifold too, and there's lots of stuff in the way.
>
>Does anyone have any suggestions for how I can best bandage this joint? I've
>packed it with exhaust repair gunk and put a jubilee clip around it to hold
>it all in but it never seems to hold for more than a few days before it's
>blown a gap out the side again.
>
>Any advice appreciated.

Is it knackered because the studs are stripped/rusted away and you
cant tighten things up properly? Thats what mine was like.

If so then you can replace the studs, or depending on the manifold
design (mine is a 2.5D which might be different) just drill right
through the manifold and use a nut and long bolt rather than a stud!
(i chose this option)

Do this, and then replace the gasket and use a bit of exhaust sealant
and it should be a goodun!.

My old exhaust fell off about a metre after the manifold (just under
the bulkhead outrigger). I lost loads of power and it was very very
noisy! - so with a bad leak right at the manifold you are likely
loosing some power.

On Fri, 20 May 2005 08:47:09 +0100, MVP <mr.nice@*nospam*softhome.net>
wrote:

>a few weeks ago (when I still had it) my exhaust spereated just after
>the first silencer box, about half way along it's length, I
>experienced free-er revving and a higher top-speed which was lost
>again when I fitted a new exhaust.

I think it all depends where the leak/end of the exhaust is!

I started with a standard exhaust on my 2A (one backbox at the rear).
It was a crappy design and would regularily break under the passenger
seat.
I could tell when it had gone as it would be slower. I kept putting
flexy sections in which would last a month or 2 before snapping again.

Then i took off my backbox and put on an old cherry bomb (which was
straight through with no filling!). That obviously gave it the right
amount of flow as the landy had loads more go in the lower gears and
pulled off well. Made no change once you were going or to top speed.
It was damn noisy though (kinda in a good way though! ).
I could still tell when the flexy section snapped.

I eventually got sick of it snapping and welded up a short exhaust
pipe that ended in the cherry bomb that exited the landy just behind
the passenger seat. This made it very very loud and throaty, but was
obviously a bit too short as it felt like it had lost me a bit of the
extra go (but it was still better than standard)

Eventually the front of the cherry bomb rotted away and it completeley
broke, leaving me with a ~1m long exhaust that finished under the
passenger floor. The moment it broke i could tell as the landy
suddenly became very slow and sounded like a tractor!

I'm back on a standard exhaust now but of a better design that is
routed differently and doesnt keep snapping!. I miss the improved
pulling off speed of the cherry bomb but this is a bit quieter which
is nice.

If it is the typical silly joint that I had on my SerIIIR6 then you are in
for a hard time. It is just a bad design. One thing I would look for
however, is that the exhaust is mounted to the gearbox . Ie the whole front
part should move with the engine, allowing the jumping around to be handled
from the rear hangers. If the gerabox mount is not present, guess where any
movment every time you rev of pull away is going to occur?

Regards
Stephen


"Tom Woods" <[email protected]> wrote in message
news:[email protected]...
> On Thu, 19 May 2005 22:47:06 GMT, "h" <h@@at@@howiem.com> wrote:
>
>>Hi all,
>>
>>According to a friend, it's a typical problem for [series 3 2.25l diesel]
>>landies like mine - the connection between the exhaust manifold and the
>>downpipe is knackered. Much of the exhaust never gets as far as the
>>tailpipe, and the thing makes the most dreadful racket, especially early
>>in
>>the morning when the neighbours were asleep. Feels like I've losing power
>>too, something to do with backpressure (?)
>>
>>I've replaced the rest of the exhaust (woohoo! my first exhaust change)
>>but
>>understand that the downpipe is particularly tricky as it will probably
>>mean
>>changing the manifold too, and there's lots of stuff in the way.
>>
>>Does anyone have any suggestions for how I can best bandage this joint?
>>I've
>>packed it with exhaust repair gunk and put a jubilee clip around it to
>>hold
>>it all in but it never seems to hold for more than a few days before it's
>>blown a gap out the side again.
>>
>>Any advice appreciated.
>
> Is it knackered because the studs are stripped/rusted away and you
> cant tighten things up properly? Thats what mine was like.
>
> If so then you can replace the studs, or depending on the manifold
> design (mine is a 2.5D which might be different) just drill right
> through the manifold and use a nut and long bolt rather than a stud!
> (i chose this option)
>
> Do this, and then replace the gasket and use a bit of exhaust sealant
> and it should be a goodun!.
>
> My old exhaust fell off about a metre after the manifold (just under
> the bulkhead outrigger). I lost loads of power and it was very very
> noisy! - so with a bad leak right at the manifold you are likely
> loosing some power.
>

"fanie" <[email protected]> wrote in message
news:[email protected]...
> If it is the typical silly joint that I had on my SerIIIR6 then you are in
> for a hard time. It is just a bad design. One thing I would look for
> however, is that the exhaust is mounted to the gearbox . Ie the whole
> front part should move with the engine, allowing the jumping around to be
> handled from the rear hangers. If the gerabox mount is not present, guess
> where any movment every time you rev of pull away is going to occur?
>
> Regards
> Stephen

Didn't realise there was supposed to be a mount to the gearbox, no wonder my
exhaust keeps detaching itself at every opportunity... I'll look into it,
thanks.

h

"Tom Woods" <[email protected]> wrote in message
news:[email protected]...
> On Thu, 19 May 2005 22:47:06 GMT, "h" <h@@at@@howiem.com> wrote:
<snip>
>>According to a friend, it's a typical problem for [series 3 2.25l diesel]
>>landies like mine - the connection between the exhaust manifold and the
>>downpipe is knackered. Much of the exhaust never gets as far as the
<snip>
> Is it knackered because the studs are stripped/rusted away and you
> cant tighten things up properly? Thats what mine was like.

Yup - it doesn't even feel like there is a stud left in two of the three
holes, d'oh

> If so then you can replace the studs, or depending on the manifold
> design (mine is a 2.5D which might be different) just drill right
> through the manifold and use a nut and long bolt rather than a stud!
> (i chose this option)

Hmm... the main problem seems to be getting at the thing; AIUI a new
manifold with shiny fresh studs wouldn't cost that much. Never tried
drilling through such chunky bits of metal before, doubt I've got a drill
bit that would survive

h

h wrote:
>
> Hmm... the main problem seems to be getting at the thing; AIUI a new
> manifold with shiny fresh studs wouldn't cost that much. Never tried
> drilling through such chunky bits of metal before, doubt I've got a drill
> bit that would survive

It's only cast iron so it's pretty easy drilling. Do not use any
lubricant - or if you feel you must just use a couple of drops of kerosene.


--
EMB