Re: cracked 2-piece manifold for MC...

["Steve Marinello" <smarinel@neosoft.com>]

When I pulled my ur-q manifold after hearing the dreaded "ticking" after a Q
Club Second Creek weekend, I found four busted studs; two old, two new...but
the manifold except for the most minor of surface crack/etching, was fine.
The motor mounts were all original.

Steve

----------
>From: "Buchholz, Steven" <Steven.Buchholz@kla-tencor.com>
>To: "'qlist'" <quattro@audifans.com>
>Subject: RE: cracked 2-piece manifold for MC...
>Date: Wed, Sep 8, 1999, 12:45 PM
>

> Well, on my '88 5kCSQA the exhaust system and motor mounts are all in fine
> shape, AFAIK they've never been replaced either.  When I pulled the EM to
> have it resurfaced (which is all that I needed to do when I did the ur-q
> years ago) the shop that was going to do the work showed me a couple very
> small cracks in the EM near where the #4 and #5 runners connect to the main
> collector ... fortunately I had procured an EM without cracks from a qlister
> as insurance ...
>
> While I would agree with a statement that broken studs can be correlated to
> motor mount and/or exhaust system stresses, I'm not so sure I've bought into
> this causing the cracks ...
>
> Steve Buchholz
> San Jose, CA (USA)
>
>> -----Original Message-----
>>
>> << I am slowly becoming _convinced_ that manifold cracking is largely
>>  caused by failing motor mounts, especially the one directly under the
>>  turbo. >>
>>
>>     I definitely agree.  Imagine the force of the entire
>> exhaust system
>> constantly wrenching back and forth on the manifold, must be
>> very hard on it.
>>  I have found that the problem is exaggerated when the
>> mounting point for the
>> down pipe has been removed,  putting all the stresses on the
>> manifold.
>>     I think that the drivers side motor mount is especially
>> critical since
>> the motor is pulling up on that mount.  If that one happens
>> to break, the
>> motor really bounces around.  In my experience, I have never seen the
>> passenger side mount fail, it is always the drivers side
>> since it takes most
>> of the abuse, IME...
>