[s-cars] Engine Cutout

[Bob Rossato]

This is now the 3rd car, including mine, that I've heard about with this
problem.  If you're having the same problem as me, your tach is reading low
by ~17% and you have actually reached the 7200 rpm redline.  Check your RPMs
vs. speed.
Here are some calculated RPMs vs. speed for 3rd, 4th, & 5th.

                     MPH
RPM     3rd        4th       5th
2000     29.3      38.7     49.3
2500     36.6      48.4     61.6
3000     43.9      58.0     74.0
3500     51.2      67.7     86.3
4000     58.5      77.4     98.6
4500     65.8      87.1     110.9

You can also rev the engine in neutral to rule out whether it is a
detonation problem but you'll find it hits the same 6000 rpm wall.  I also
swapped ECUs with a local lister with no change.  In the end I found out
that the problem is with the circuit board in the Instrument Cluster.  I had
obtained a spare IC for the purposes of swapping the tachometer, however, my
IC with the other tach had the same problem and the other IC with my tach
would rev all the way to 7200rpm.  Unfortunately, the other IC is metric so
I'm still running my IC and living with the problem for now.

Check your IC and I think you'll find evidence that the circuit board has
been replaced.  On mine there was a part number label that was applied
across the interfaces of the back cover and front housing so it was torn in
order to separate the back cover.  I'm thinking that our cars must have had
warranty work done on them for some problem on the IC and they used a V6
circuit board in the replacement.  Don't know why that would make a
difference since the signal is coming from the crankshaft RPM sensor, not a
spark plug, but coincidently 5 is 17% lower than 6.

Bob

> -----Original Message-----
> From: s-car-list-admin at audifans.com
> [mailto:s-car-list-admin at audifans.com]On Behalf Of Andrew Pennell
> Sent: Monday, October 21, 2002 9:25 PM
> To: s-car-list at audifans.com
> Subject: [s-cars] Engine Cutout
>
>
> I have a 95 S6 Avant. At approx 6000RPM the engine will act as if it
> hit the redline. No ECU faults and the engine is otherwise running
> well. Any ideas? It seemed odd that it would cut out at that speed. I
> was only aware of the redline and "limp home" condition that would
> cause engine or fuel cutout.
>
> -AP