Classic Mustangs List Archive

This read-only message was archived from a public mail list.
Mail From: Rob Enns (email redacted)

Hi,

First, let me say thanks for all the good advice I've gotten as
a list lurker for the last few months... now on to the question
(please forgive me if this is a dumb question):

I have a '66 coupe with a 289 and dual exhaust. For the last
couple of months the engine has been louder than normal and I
also hear 'pinging/metallic' sounds under acceleration (as
far as I can tell the timing is okay).

I replaced the donut gaskets between the exhaust manifolds and
the pipes (they were very 'rotted' out), and this quieted the
sound a bit. However I'm wondering if there is also a leak between
the heads and the manifolds. Is there any way to detect an
exhaust leak?

Thanks,
Rob.

This read-only message was archived from a public mail list.
Mail From: TRAVIS E KASNER (email redacted)

Is there any way to detect an
> exhaust leak?
>
> Thanks,
> Rob.
>
>
One thing that I do to determnine where a sound is coming from is
to take a section of old heater hose, put one end to your ear, and move
the other end around the engine. This way you can limit the area that you
are listening to. I have done this before to determine whether a sound was
a manifold leak, or doughnut gasket etc., and it has always worked for me.
Good luck.



Travis Kasner
1966 Fastback G.T.

This read-only message was archived from a public mail list.
Mail From: Max Watson (email redacted)

Rob Enns wrote...
>I have a '66 coupe with a 289 and dual exhaust. For the last
>couple of months the engine has been louder than normal and I
>also hear 'pinging/metallic' sounds under acceleration (as
>far as I can tell the timing is okay).

Uhhh... Pinging generally means the timing _isn't_ okay! Pinging is caused
by pre-detonation. Carbon deposits can cause pinging with an acceptible
timing setting. Set your timing with a vacuum gauge. It works 100x better
than a timing light. The goal is to acheive maximum vacuum without a
fluctuating needle. Do this at normal operating temperature.

>I replaced the donut gaskets between the exhaust manifolds and
>the pipes (they were very 'rotted' out), and this quieted the
>sound a bit. However I'm wondering if there is also a leak between
>the heads and the manifolds. Is there any way to detect an
>exhaust leak?

You can 'hear' an exhaust leak coming from the manifolds. You've just got
to know what it sounds like. Enlist the help of a gear-head friend.

However, I've found that a great deal of engine noise is generated by the
belts! Pick up some "belt dressing" at your local autostore and watch with
amazement as the engine magically runs quieter.

--
D. Maxwell Watson Santa Rosa, CA
<(email redacted)> TractorFactor.base.org

This read-only message was archived from a public mail list.
Mail From: wrk (email redacted)

When I had my muffler replaced a couple of months ago,
the muffler shop told me I had a crack in my exhaust manifold.
When I replaced the engine a couple of weeks ago, I found that
the passenger side manifold was completely broken in two.
Apparantly, the muffler shop and the inspection site missed this
because it was under the heat stove. I had a spare manifold, but
before I put it on, I noticed that it had a small (2 in.) hair line crack
in the same place that the other broke. This was right in the middle
of the manifold between cyls. 2 & 3. You might try using a piece of
heater hose to your ear to listen for a leak. Just make sure you
don't get it caught in the fan or something ;-).

Russell Kumpe
(email redacted).



*********** REPLY PARTITION ***********

On 09/18/97, at 06:00 PM, Rob Enns wrote:

>Hi,
>
>First, let me say thanks for all the good advice I've gotten as
>a list lurker for the last few months... now on to the question
>(please forgive me if this is a dumb question):
>
>I have a '66 coupe with a 289 and dual exhaust. For the last
>couple of months the engine has been louder than normal and I
>also hear 'pinging/metallic' sounds under acceleration (as
>far as I can tell the timing is okay).
>
>I replaced the donut gaskets between the exhaust manifolds and
>the pipes (they were very 'rotted' out), and this quieted the
>sound a bit. However I'm wondering if there is also a leak between
>the heads and the manifolds. Is there any way to detect an
>exhaust leak?
>
>Thanks,
>Rob.
>
>