ASR question S8

hi there
i have bought another 2001 S8 for a winter hack. I did the same last year, what a great car. This one is generally in very good shape although has a couple of issues-
Slight misfire on tick-over noticeable when stationary in D with a pulsing/shuddering. engine pulls ok so i suspect a coil pack so will swap the offending item. when putting i new plugs i noted one of them was wet with petrol so will replace the CP for that plug.
slightly more concerning is that when i press the ESP button the dash light doesn't come on warning the system is turned off. In fact, the traction control system doesn't seem to be working at all....where can i find the control module??
i had cause to drive on a muddy field on bonfire night and the power didn't shut off when all the wheels were spinning....Does any one have any experience of a similar issue and how to resolve it?
finally and not really an issue is the electrically retractable rear headrests, i can hear the motor whirring but nothing happens, its not obvious how to get to have a look at the mechanism....any pointers??

thanks in anticipation.
richard

[r8dream]

welcome,
the coil packs on the '99 to '02 s8's never go, it's other audi/vw engines that have that problem.

have i posted this in the wrong section?
38 read and 1 response.
thanks

[Conan_the_Librarian]

Richard,

The vast majority of readers on here don't contribute. Those that do don't look in every day. Those that do contribute and may know the answer may not have looked in yet.

I can't help much on the ESP issue. The ABS Control Unit is under the engine ECU if I remember correctly and if moisture has got in (a regular occurrence if the lid has not been put back properly) then a dry out with a hair drier may help.

You can check your coil pack problem by swapping the CPs over and see if the misfire issue moves. If it doesn't it ain't the CP. Do you have VCDS? A print out from that may help. If it ain't the CP then the plugs may be the culprit. Swap them about and see if the misfire moves.

On the headrest issue. If the headrest has been removed it may not have been pushed back in far enough to engage; or it may have been replaced with excessive force. They are only plastic cogs.

Welcome to the forum BTW.

[Just_Ben]

If you're ESP system was/is dead it should constantly warning you with an ESP warning in orange and a large red flashing ABS warning on the DIS. This is what happens if you disconnet the module completely.
That needs diagnosisng properly, sounds funny, like possibly someone has coded ESP out of dash pod all together due to an expensive fault and the desire to get the lights off the dash.

The miss at adle could be a few things but as R8DREAM says, a coil pack is pretty unlikely. Possible but unlikely.
I would check for air leaks on inlet manifold, especially at the variators and their actuators. Also check at the Secondary Air inlet valves (back of each head) as if they become stuck open they can let air in. Failing that it could be more in deoth, such as failed injectot (or just clogged giving poor spray pattern) or loss of compression. Also, make sure of when timing belt was done last and if they did it right! Incorrect valve timing can cause funny issues!

thanks guys

the air intake box housing the MAF and filter isn't seated correctly, the two bolt heads are sheared on the bottom edge. i have ordered a new air box housing and am confident this will be the fix. swapping the CP's around didn't seem to make any difference.


i am going to try a replacement dash micro switch for the ESP problem, if that fails then its off to votex in congleton for a check up.

the car is generally really good so i don't mind the odd issue.

i am also missing a sat nav disc so if anyone has a steer on how to obtain one i would be most grateful.
thanks again for your help to date.

[The_Laird]

You can buy the discs for the sat nav on fleabay or...

...I'm awaiting delivery of a more recent one and will have a 2002 disc for sale very soon if you're interested