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FAQ so far...

> Below is the first crude draft of an Audi FAQ, which I started an 
> embarrassingly long time ago

> Anyway, here it is. Anyone who wants to improve upon or add to it is
> very welcome. If anyone wants to fill in some of the blanks, please
> email me your text and I'll stick it in. 

OK, here goes.....

>  1.2 Are they reliable? Are they good value?
>    Generally speaking, yes. The powertrain and other basic parts of the
>    car are very reliable, and rust is rarely a problem.

Powertrain is also extremely durable, with several mailing list members
reporting cars driven daily with mileage in excess of 300,000.

The older models were average in their susceptibility to rust.  Starting in
the mid-80s, though, Audi bodies were galvanized (zink dipped) and rust
became rare.  (at least the 5000s are - don't know about the 4000/80/90)

>However, the
>    luxury add-ons are less reliable, and things like electric windows,
>    powered sunroofs, and the like can often develop small nagging
>    defects.

The hydraulic system for power assist to brakes and steering was
particularly troublesome on the Audi 5000/100 from 84-??  The cars from the
earlier part of this range are worse than the newer cars.

>  1.4 What was the 'unintended acceleration' business all about?

> The actual cause of the problem was that 
>    the pedals on the Audi were closer together than on many American cars, 
>    thus causing some people to hit the wrong pedal (and to press it harder
>    faster the car accelerated.)
The cars were cleared by an official investigation of the U.S. National
Highway Transportation Safety Board, a U.S. Gov't. agency responsible for
determining design defects in motor vehicles.

>  2.1 Where can I find Audis advertised?
>    In the US: Subscribe to the 'quattro' mailing list.
>               [There must be others?]
>    In the UK: "VW Audi Car" magazine has a classified section each month.

>Newspapers in larger cities often advertise Audis for sale.

>  2.3 What points should I look for on a used Audi?

>    Check all electrical items - windows, sun roofs, etc.

The power window switches on many models were susceptible to corrosion on
the internal contacts.  This is the most common cause if one window doesn't
work (and makes no sound).  The mechanism for raising and lowering the glass
sometimes brakes too (you will hear the motor but the window won't move
properly).  The parts for fixing this malady cost about $150US aftermarket
and the repair requires a couple of hours.

The sunroof mechanism is lightweight.  Without proper lubrication, the parts
often wear or break.  Parts are relatively expensive, although "recycled"
ones are often available.  This repair takes at least several hours,
possibly most of a day.

The door handles also require proper lubrication.  Without it, part of the
mechanism fatigues and breaks.  Repair is straighforward, but takes a few
hours.  The handle costs about $60US aftermarket.

By far the most important area to examine closely are the hydraulics.  The
introduction of conventional power steering fluid into a 5000/100 designed
for special hydraulic fluid (generally, those manufactured from '84 to
.....?) trashes the seals in the system, leading to a need for extensive
repairs.  The first area to check is the steering rack.  Look for signs of
oil in or leaking from the boot on the rack (visible from above at the back
of the engine compartment).  The rack takes about 6 hours to change and
costs for a rebuilt one range from $250 to $600US.  Examine the hydraulic
hoses, as these are not cheap either.  Finally, check the pressure
accumulator in the braking system by pressing the pedal with the engine off.
You should get at least 15 applications before there is no boost, with 25-30
applications if equipped with a new accumulator.

The radiator and heater core are metal with plastic side tanks.  These often
leak on older cars, particularly if cheaper aftermarket coolants have been
used extensively.  The heater core typically leaks onto the front passenger
floor (driver's floor in the UK?), if the leak is active, you may notice
fogging windows, the syrupy smell of the coolant, or coolant under  the
floor mat.  Replacement takes about 6 hours but the part is affordable at
around $80US aftermarket.

The only catastrophic problems to look for are:
        1. overheating (and warping the aluminum cylinder head) (compression
        2. bad radiator fan bearings have been known to seize, causing the
already considerable current draw of the radiator fan to jump, frying the
wiring harness (rare)
        3. a broken timing belt on 20 valve or turbo equipped cars can
result in damaged valves and heads (the 10 valve normally aspirated engine
has non-interfering valves).

>      6.5.2 My temperature guage isn't working.

On the 5000, this is most often the result of a failure in the sender.  Air
Conditioning equipped cars have two coolant senders.  A two electrode sensor
switches on the overheat lamp when the temperature exceeds about 250F.  The
other sensor has 3 or four pins (depending on whether it was updated or not)
and controls both the temperature guage and shuts down the air con
compressor when the engine gets hot.  Replacement of this sensor is pretty
simple - you just screw it out and replace.  Its located near the connection
of the lower radiator hose and the engine.  Before you do this, though, its
worth cleaning the ground strap that attaches to the back of the valve cover
and measuring the output of the instrument panel voltage stabilizer.  You
can do thri from the sensor electrical plug - you should measure between
9.75 and 10.25 volts between the correct two wires.
>Section 6 - Maintenance and Repairs
>    [Insert disclaimer about this information not being guaranteed.
>    Advise readers not to attempt anything they don't feel competent
>    to do. Some basic safety advice.]
>    [Note that I was intending this as a supplement to the manuals,
>    and to point out pitfalls and shortcuts. E.g. the manual says
>    "unscrew this" and the screw won't budge...]
>  7.1 What manuals do I need?

The best manuals are the "Official Factory Service Manuals" published by
Robert Bentley in Bostan Mass, USA.  These cover only American and Canadian
models and are rather expensive.  For example, the 84-88 5000 manual is now
around $130US.  They are sometimes rather cryptic and refer to specialized
dealer tools, but they are the most accurate and extensive.

Haynes publishes the a reasonable manual at a reasonable price, around $17US.  

Chilton's manuals are widely disliked.

A good general background book for the beginner is the (now out of print)
guide to rabbit (Golf) repair published by John Muir publications. Although
the rabbit was a far simpler car, much of the design and philosophy is similar.

>  7.2 What tools do I need?

Most of nuts and bolts on VWs and Audis are odd metric sizes (e.g., 13 mm).  

>  7.3 Where can I get spare parts?
>  7.4 Regular maintenance items
>    7.4.1 What Oil & Oil filters should I use?

> Oil filters made by Mahle, Knecht and
>    Mann are excellent and are OEM suppliers to VW, Audi, BMW and
>    Mercedes. (Avoid FRAM filters - they don't have the valves, and their
>    internal construction is poor.)
Bosch is now marketing filters that can often be found at automotive
discount stores.  Boshc enjoys and excellent reputation from their ignition
and injection systems, so these filters are probably pretty good.

While under the car, make sure to examine the CV joint boots and brake lines
for signs of deterioration.

>7.5 ???? (Numbering duplicated)

7.5.x Timing Belt replacement:

Audi does not publish a recommended interval for replacement of the timing
belt.  Like most preventive maintenance operations, the proper interval
depends on who you talk too.  Some folks say 60,000 miles, some say 100,000,
some say to let it go until it breaks (on 10 v normally aspirated engines).
In any event, it is possible to peak at the belt (use a metric hex key to
loosen the top cover on the front of the engine), and caution would dictate
replacement of a belt contaminated with oil (and fix that leaky valve cover
gasket while you are at it!).

Replacing the belt should be relatively straightforward on the 4 cylinder
engine.  The five cylinder, however, is somewhat more tricky.
Unfortunately, removal of the pulley attached to the crankshaft is
necessary.  It is at the bottom front of the engine.

Dealers use two special tools for replacing the 5 cyl.  timing belt.  The
first is a sturdy breaker bar and socket.  The tightening torque is rather
high (over 200 ft-lbs on the lower powered versions), so good quality is a
must.  The second tool is a device to lock the crankshaft pulley to the
block to prevent it from turning.  Some folks report sucess jamming a pry
bar into the flywheel, but this technique could result in missing flywheel
teeth.  It is probably better to use the right tool or to have it done

The easiest way the get access to the pulley is to remove the front bumper,
which can be done by removing two bolts.  It is also necessary to remove all
of the accessory drive belts, so this is a good time to replace them.  Note
that more than one alternator pulley was used on various years, so it is
possible that your car will require a different size belt than the one
listed in the owner's manual.  This is also a great time to replace the
water pump, as the pump can only be replaced by removing  all the belts.
Further, the pump is used to tension the timing belt.  Moving an older pump
to loosen the old timing belt and then to tighten the new one is often more
than an old gasket can handle.  The cost of a new pump is around $60US

7.5.x+1 Valve Cover Gasket

This gasket is often neglected, resulting in leaks onto the intake manifold.
These gaskets just plain wear out. Replacement takes about an hour and the
part is cheap.  Just be careful not to overtighten the nuts - about 7-10
ft-lbs is enough.

>  7.6 Brakes

The brake fluid should be completely replaced every two years to avoid
moisture buildup.  Excessive moisture can cause premature brake fading (it
lowers the boiling point of the fluid) and corrosion in the braking system.
With proper maintenance, anecdotal evidence on r.a.vw suggests the the
hydraulic brake and clutch parts should last nearly forever.  Without.......

Several methods are suitable for bleeding.  The most practical are pressure
bleeding (which requires additional equipment), use of a hand held vacuum
pump (no pleasurable because of leaks between the bleed screw and the body
of the brake cylinders), and a friend to press the brake pedal.  Which ever
method is used, depress the pedal 30 times with the engine off the dissipate
pressure in the accumulator, use fresh, top quality DOT 3 or 4 fluid, and
bleed in the following sequence: RR, LR, RF, LF, clutch slave cylinder (if
manual equipped).  

The bleed screws require a 7 mm wrench.  If stuck, try a drop or two pf
brake fluid on the threads.  Be careful, as break fluid is a very effective
paint remover.

Bleeding the hydraulic clutch circuit is often omitted by many shops in a
hurry perhaps  because it it not safety related.  In any event, this often
leads to eventual failure of the master and slave cylinders.  Although the
manual states that these can only be bled using a pressure bleeder, at least
one net member reports good results with the following technique. 
 1. Keep the reservoir topped up. 
2. Attach a clear hose (cheap stuff) to the bleed port on the slave cylinder
and put the other end in a jar that is higher than the reservoir.  You can
rest it on the cowl.  You need about an inch of fluid in the jar.
3. Open the bleed port and pump the pedal very slowly (~10 sec per stroke
and return).  After a little while, the hose should fill with fluid.
Continue until no more bubbles float up the hose.

Total time should be 5-20 minutes.

If you get desperate or want to get crazy, try to fill the clear hose before
bleeding.  You might even want to fill the fat hose from the reservoir to
the master cylinder (using a clean funnel?).

>  7.7 Electricals
>    7.8 Climate control