Re: V8 surge problems

[Eliot Lim <eliot@u.washington.edu>]

> Today I took my 90 V8 to the dealer for a repair, it is also due for 
> its 90K service so I asked about the Ox sensor because I have 
> noticed the same exact symptoms that you have described.  They 
> explained that a bad Ox sensor would cause surging only at idle.  
> Therefore, this could not be the cause of the problem.  I tend to 
> believe them, because have you ever heard of a dealer *not* wanting 
> to perform a service!

the reason for this is because there are no official audi factory
bulletins advising them of the problem.  if they went ahead and
changed the OXS and did not fix the problem then they would be
up s*** creek wouldn't they?

>  They explained that this problem is inherent 
> to the V8 and something that they have narrowed down to a 
> transmission software problem.  Since my car has the original 
> transmission software, possibly that could help?  Eliot might shed 
> some light on that.

that is crazy.  how could the software cause the surge?  the torque
convertor is a fully mechanical device.. the electronics do nothing
more than make shifting decisions.  this problem has nothing to do
with shifting decisions.

my car had the problem before and after a complete transmission
and transmission control unit swap.  the problem disappeared when
the OXS was replaced.. it is pretty conclusive as far as i'm
concerned.

if you looked at the exhaust layout of the V8 it is pretty nutty.
the pipes coming in from each of the bank meet in a "H".  the OXS
sits right on the horizontal bar of the "H".  most of the exhaust
gases just go straight through the "vertical bars".  that's why
the OXS is doing such a poor job.


eliot