[A8] Things you need to know

[David G]

I just did a huge service on my 97 A8:  timing belt, water pump, struts,
spark plugs, coolant, transmission.

Let me share this:

Timing Belt every 90K

Religious at 90K, not zealous. I did NOT replace any of the idler bearings,
water pump or thermostat, tensioner shock absorber. Although I did take a
needle and squeeze grease into one of the bearings that seemed a bit more
free than others. But I don't pay $100/hour to a garage so if I get any
failures it's just another day of labor. This time it was by the Gods:
replaced idler bearings and tensioner bearing and piston. Kept original
thermostat again.

Transmission every 60K

The first service there were huge amounts of magnetic material clinging to
the magnets. The 2nd time less. The 3rd time less again. I have had no
issues ever, never, from my DPZ transmission. BUT I do control the shifting
so that the engine speed is above 2000rpm when the trans has to do heavy
lifting.

Water Pump at 190K.

Yes, there was a slight coolant track coming from the water pump but not
enough to ever have added coolant. I had the red G-12 in there since factory
install in 9/96. Now it is lavender G-12 and a new Bosch water pump. When I
ordered the Bosch WP, a Beck Arnley showed up. During the exchange I
actually had 3 water pumps for comparison purposes on hand. They have these
differences:
The factory (aka OOOO) water pump has a plastic impeller, others were metal.
Bosch has a larger diameter pulley which calculates to run 20% less than
others. Bosch has 4 (versus 2 for Beck Arnley, 0 for OOOO) holes drilled
into the impeller. I believer these holes provide circulation behind the
impeller, a good thing for the bearing. The shaft attaching the BeckArnley's
impeller was noticeably smaller. I couldn't make any judgements about this
without disassembly. It was returned for credit without autopsy.

Thermostat - still operating

My theory on thermostats is: If it isn't broke, leave it alone. I have the
same attitude for alignments: If tire wear indicates good alignment, don't
let those HS kids near your car with wrenches.

Shock/Struts 

These should have been replaced MUCH earlier than 190K. But the car is so
solid it doesn't give much indication. I had a small vibration at speed. It
went away with new shocks. If I had a chance to re-do this I would try
harder to get the Boge instead of Bilsteins. The Bilsteins had a smaller
body and a very slightly smaller piston rod. I tried to get the B6 versions
but it doesn't look like I did, although they are designated HD. The
Bilstein's piston stroke was a couple inches longer which allows for a
lowered suspension.

Replacing the rear shocks was a piece of cake. Don't bother removing the
springs as written in the manual. Push up on the suspension to remove spring
tension from the shock's lower bolt. Remove. Don't relax.

Replacing the front shocks went pretty much by the book. When the strut is
finally out of the car I used my cheap spring compressors to finish. Of
course, my pinch bolt wasn't rusted in place as I hear from all of you in
the East.

The ride at first was a bit harsh at lower speeds. 200 miles later it has
improved. I get jostled at low speed, just a bit of drumming (inaudible, not
heard but felt as sound pressure in the ear) in the 20-30 speed range.
Everything from 50mph and up is awesome. Bilsteins for handling, Boge for
comfort. I think that's well known.

Spark Plugs

Stock stuff here. Much improved torque and shifting. Yes, shifting. If
you're A8 is shifting slow it might just be that missing bit of torque that
will fix it.

I have pictures on the water pump and strut comparisons. If you're curious I
can send them. If I find how to post them you can all enjoy the research.

Amazing. A new car feel at 190,000 miles.

David G.