Broken exhaust manifold studs

[Darrell Boehler]

Hi Eyvind,
    If you have room to use vise grips or weld a nut to the stud then try heat.
Get the stud hot and then let it cool. Your 15-25 mm should work this way.
        If the stud breaks down in the hole and prohibits even the welding of
a nut to the stud then drill the stud out.  The smaller drill you start with  the
better as it is easier to get the drill centered.  Now step up the size of the
drill gradually until you have the stud removed.  I repeat get the drill centered.
I drill out and tap the head for 10 mm stud. You can use 10 mm studs and nuts
on an mc engine not sure about the 20v.  If a 10 mm nut is too big on your
manifold you can get studs that are 10mm on one end and 8 mm on the other.
 I have used the 10 - 8 mm on vw boxer engines where a 10 mm nut is too big.
The 10-8 mm are expensive $5. The 10 mm are about $1. Flaps (friendly local
auto parts store) should have them. Don't forget to increase the size of the hole
on your manifold. The studs / manifold  need room to wonder around a bit.


Bentley suggests 35 nm torque on the exhaust manifold bolts, I tend to
feel this may be excessive.  25 nm feels better to me, any other thought out there?


Darrell

----- Original Message -----
From: "Eyvind Spangen" <eyvind.spangen at c2i.net>
To: <quattro at audifans.com>
Cc: <200q20v at audifans.com>
Sent: Thursday, March 28, 2002 6:44 AM
Subject: Broken exhaust manifold studs


> Three exhaust manifold studs snapped today while removing the (_very_
> cracked) exhaust manifold on my '90 200TQ20v. The parts sitting there
> extends 15 to 25 mm from the head.
>
> How do I remove them? I don't want to attempt this myself before
> asking you all on the list! :-)
>
> BTW, should all the studs be replaced while I'm in there?
>
> --
> E. Spangen
> '90 Audi 200TQ 20v