Audi S4 Biturbo User manual

The Audi S4 Biturbo
A buyers guide
By Nilesh Ramrattan
1. Homework
2. Model Specifics
3. Choosing a Vehicle
4. Options
5. Finding an S4
6. The phone call
7. Modifications
8. Bodywork
9. Servicing
10. Recalls
11. Test Drive
12. Transmission
13. Brakes
14. Electrical
15. Engine
16. Interior
17. Screening
18. A time to buy…
19. Buyers Checklist
20. Checklist The Audi S4 Biturbo
OK – So now you’ve done your homework – you’ve
decided that you want a fast yet understated saloon or
estate car (sedan or station wagon).
You’ll want a car that will last, a car that is
safe, sure footed, and to a certain degree a
car that you can “grow” with.
You want a six-speed manual or tiptronic transmission,
permanent four-wheel drive, and a six cylinder turbo-
charged engine with the very latest five-valve per
cylinder technology, superb build quality, and lots of
“go”.
You’ve convinced your better half and your bank
manager, you’ve checked with the insurance company
that you can be covered and you’ve satisfied your
conscience that you’ve made the “right” choice.
You’ve made the decision to buy an Audi S4. Here’s
how to make the vision into reality...
Model Specifics
Where do you go from here? Well, firstly you might
want to appreciate that the Audi S4 biturbo was first
released in Europe in 1998, with North America and
Canada being introduced to the model in 2000, so there
are actually two different models available in Europe.
The external differences can be seen quite quickly, with
early vehicles featuring square side-repeaters, thin
body-mouldings, flush mounted door handles, and
Xenon headlamps with separate indicators. It takes
quite an eye to see, but you may also note that the door-
mirrors on earlier cars are not quite as “angular” as
those of its successor.
You’ll also need to know when browsing through local
classifieds and dealer pages that an S4 listed as circa
1994 is not a misprint, and while it is a fabulous car,
you do not want to waste valuable time looking at it!
The early S4’s (or urS4’s as they are sometimes
referred to) are based on the last model Audi 100 cars,
and feature a 20-valve 5-cylinder turbocharged engine
as found in the Audi S2.
Audi S4’s V6 Biturbo Power Plant
Choosing a vehicle
By choosing an Audi S4 biturbo, you’ve actually cut
out some major hassles usually associated with car
buying right from the start.
At the time of writing, the oldest Audi S4 biturbos have
only been in circulation for under 3-years. This means
that in most cases, you can rely on them having
relatively low mileages, having been well looked after,
sporting service history from the main dealer, and still
benefiting from the manufacturers warranty.
Problems such as rust, mechanical wear, and other such
issues do not really come into the equation when
buying an S4, especially since the car is fully
galvanised and because it is exceptionally robust. But,
as with all cars (and there is a but), there are some
issues you do need to be made aware of – most of
which stem from cars that have been modified, cars that
have been poorly repaired after accidents and cars that
have been repaired after vandalism.
Be aware that although the Audi S4 biturbo is limited to
a low annual production figure, there is a good quantity
available on the market to choose from, so if at first you
don’t find quite what you’re looking for, try the next
one!
For worry free motoring it is recommended that you
choose an example with low to average mileage, a

guide figure being 12,000 miles annually, no
modifications, and full details depicting the car’s
history in terms of servicing, manufacturer recalls and
warranty.
This is only a guideline, but as with many things, there
are exceptions to the rule.
It’s usually cars that have not been modified which are
the most desirable and sought after.
The downside of being a desirable vehicle is that the S4
is also prone to “ringing” – that is a vehicle which has
had its identity changed after being stolen or repaired
following serious accident damage – we’ll go into how
to safeguard yourself as much as possible from this later
when we discuss “screening”.
Options
The Audi S4 can be specified with a myriad of options,
almost equating to a third of the cost of the basic car.
This provides for the original purchaser to tailor a car
that is very unique indeed.
It’s also one of the reasons that one S4 can
be difficult to price in comparison with
another.
Our advice is firstly to define your choices in terms of
basics such as Colour, Interior, and then “niceties”, such
as sunroof, CD player, Satellite navigation and the like.
Available S4 Colours
The car is available in nine colours, Laser red, Black,
Cactus green, Hibiscus red, Imola yellow, Santorin
blue, Nogaro blue, Pearl white and Silver. The most
expensive paint finishes are Pearl white, Nogaro blue
and Imola yellow, all of which are available by special
order.
The interior is available in a selection of three material
combinations - Jacquard satin cloth, leather, or a
combination of leather and Alcantara – a man made
suede-like material available in a vivid blue or
platinum.
Blue Alcantara Interior
Door and Dash inserts are available in three variants,
walnut burr, silver aluminium and carbon fibre – note
that not all finishes are available in all markets – for
example, walnut burr is not available in the UK.
So, once you’ve established a basic specification for
your potential used S4, decide on what you would
compromise should push come to shove. You might
belay a sunroof in favour of satellite navigation, or
alcantara for leather – give yourself some flexibility.
Finding an S4
Finding the car you want shouldn’t be too tasking. The
most preferred way to buy a used S4 is to source one
via an Audi main dealer or an approved Audi main
dealer Internet network, but if you want to save money
and are prepared to do some legwork, take a look at the
local classifieds. “Auto Trader”, “Car Finder”,
“Exchange and Mart” are all excellent ways of locating
a car and saving money over dealer prices.
If you have access to the Internet, you may wish to try
using a search engine from the many available, to
locate a suitable vehicle in your vicinity.
Draw up a list of potential vehicles – unless you’re at a
dealership, don’t visit more than four cars in a day.
Exceeding this number usually results in an impulse
buy when you are tired and running out of steam, or
will facilitate you in missing important clues that may
come to haunt you later.
The phone call
Using your list of potential vehicles, give the owner a
call – do speak to the owner. Ask them the type of
questions you feel you need answered.
Arrange where possible to view the car during daylight
hours. In your initial call, you should look to find out
basic information.

Firstly, try to discover why they are selling the car.
Check that their rational is reasonable. Remember, the
car you’ll be looking at will be less than three-years old,
so you need to find out why it’s being sold. Ensure you
are happy with the mileage - ask questions regarding the
condition of bodywork, the wheels and tyres, details of
when the car was last serviced and by whom.
Find out if the car is 6-speed or Tiptronic, what
remaining manufacturers warranty there is, and if the
car has been modified. Check to see if the car has been
garaged when not in use. Ask if the vehicle has been
subject to any accidents or damage of any kind and if
so, enquire who carried out the repairs.
Is the car under a finance agreement? Does the owner
have documentation to substantiate the car is not owned
by someone else?
After ascertaining the address of where the vehicle can
be viewed, ask the owner if this is their home address.
Always be wary of
owners that offer to
meet you at
locations other than
their home. Check
with the owner that
they are happy to
allow you to test
drive the car, and if
they will give their consent to have the car screened by
Carfax or HPi (vehicle verification agencies) before
purchase.
With regards to the test drive, check with the owner that
you will be insured to drive the vehicle – be it under the
owners policy or your own. Never take the risk of
driving without checking this first – the consequences
of this can be dire!
You’ll need to feel comfortable with the responses you
are given. If you are in doubt or your suspicions are
raised, it’s best to make your excuses and phone the
owner of the next car on your list.
At the end of this article is a used car buyer’s checklist
that you should use when you view the vehicle.
Modifications
Now depending on your own personal preferences, you
may wish to purchase an original vehicle or a vehicle
that has been modified.
If you elect to go for the latter, depending on which
country or state you live in, you may be required to pay
additional insurance premiums depending on the
modifications rendered.
These cars usually tend to have issues that the main
dealer may be unable or unwilling to assist you with,
and you’ll want to note that Audi have recently revised
their policies with regard to warrantable work on
modified cars in the USA and the UK with other
countries following suit, meaning that in the event of a
problem, you’ll foot the bill.
The most popular modification to an S4 is
“chip tuning” also known as “chipping” or
“engine remapping”.
Such modifications allow the BHP and torque of the
vehicle to be increased dramatically.
Prolonged use or sustained hard driving of a modified
car can result in expensive component failure. The
most common failures being leaking intercooler pipes
which give way due to the increased pressure carried by
them and failed turbos (usually the oil seals) requiring
the engine to be removed for replacement – a very
costly procedure.
The smooth lines of the S4
Early cars pre “1999.5” as they are called, use an early
version of the K03 turbo charger and were fitted with
less resilient intercooler hoses. Audi did put a recall
out for these vehicles to have the hoses replaced under
warranty, but not all dealerships seem to do this
voluntarily – you will need to ask them to perform the
work if it’s not already been done when you take the
car in for service.
2000 model year cars seem to fare a lot better on the
modification front. The hoses used are stronger and the
K03 turbos are allegedly of a revised design.
Other popular modifications include lowering the ride-
height of the car to gain additional stability during
cornering, short shifters, to lessen the throw of the gear
lever and to give a more “solid” feel during changes,
alloy wheel upgrades and various spoiler and grille
options.

With any sort of lowering, it’s a good idea to have
geometric check done on the car to check camber and
alignment, which can prove invaluable in the long run.
The more radical of these cars can sport up to 470BHP
using parts from the later Audi RS4 and after some
expensive tuning work.
Bodywork
Avoid vehicles with panels that do not line up, cars with
spoilers or body kits that have not been correctly fitted
and look out for any signs of poorly repaired accident
damage or forced entry.
The Audi S4 comes fully galvanised and has
a 10-year anti-corrosion perforation
warranty. This puts the “rust-bug” nicely
to sleep.
If a car has replacement alloy wheels, enquire as to
where the originals are. This way you can replace them
if you don’t like the ones fitted or have yourself an extra
set of winter tires.
Ensure that the wheels are free of scrapes and chips –
any signs of such are an indication of neglect and hard
driving.
Open all the doors, one at a time and close them – check
that doors have not dropped on their hinges and that
they close first time without slamming or bouncing off
the rubber seals in the doorway. Do the same with the
bonnet and boot-lid (hood and trunk).
If the car exhibits rust of any kind on the body or under
the bonnet, you should walk away.
Check for stone chips or other damage
Check in the boot under the spare tyre. All S4s come
with a full size spare and tools including a jack. Look
for signs of damage or repair. Check under the cars
sills for damage by poor jacking. Many garages (and
some owners) fail to pay attention to the jacking points
and damage suspension, plastic trim or floor pans.
Make sure that the key for the locking wheel bolts is
available and safely stored.
If the car has been lowered, check under the wheel
arches and see if any rubbing of tyres and paintwork
has occurred. Turn the steering wheel to the left and
right and again, check for rubbing or wear.
Servicing
Regular servicing and maintenance always pays
dividends. Late model Audi S4s can go 20,000 miles
without servicing due to advancements in oil, filter and
spark plug technology. In the US, servicing is
recommended every 3,000 miles, quite possibly due to
the amount of stop-start driving done in the cities.
Ideally, all servicing should be carried out by the main dealer
The S4 should always be serviced using
synthetic oil, never mineral or semi-
synthetic blends.
Ensure that a service history document is available and
check that the book exhibits all the correct stamps and
endorsements. Don’t forget to check the latter pages to
see if scheduled brake fluid changes have been
performed. From the factory, the S4 is supplied with a
glycol-based brake fluid of DOT 4 specification. Be
wary of cars that have been topped up with silicone
brake fluids, as glycol and silicone fluids are not
compatible.
It’s important to check that the brake fluid is changed at
regular intervals as glycol fluids are hygroscopic,
meaning that it absorbs water over time and looses it’s
efficiency.
Don’t compromise by viewing or selecting a
car that has not been well cared for. To do
so will result in problems and regrets soon
after purchase.
Usually, the issuing main dealer services most cars.
This means that all the stamps in the service booklet
should match. You can always check with Audi
customer services if you are in any doubt about the
authenticity of such entries.

Cars with differing stamps do not indicate any sort of
foul play, as it is conceivable that owners move from
one area to another, or may even have had bad
experiences with some dealerships.
Recalls
We touched briefly on factory recalls when we covered
modifications. At the time of printing, we could only
find recalls pertaining to the following:
1. Intercooler hoses – early models weak
2. Dust caps on tie rod ends – early models weak
3. Vehicle with tiptronic transmission – Brake
control valve
Note that not all of these will apply to later vehicles.
Successfully completed recalls are marked
in the service history booklet and are
stamped by the main dealer, usually with a
code.
Test Drive
By now you’ve looked over the car you’ve found and
are more than comfortable. You just can’t wait much
longer to get in and take it for a spin – but before you
do – you need to check that you are sufficiently covered
by your own or the owners insurance policy.
Choose a route which emulates most driving types
Before driving off, check the condition of the tyres, and
check the fluid levels under the bonnet – oil, water,
brake fluid, power steering and washer bottle. Be aware
of any unusual smells – burning, brake or clutch lining,
fuel and the like, both before and after the test drive.
Adjust your seat, headrest, mirrors and steering column
to a position that suits you.
Locate equipment such as lights, indicators, wipers,
park brake, and emergency hazard light switches before
you pull away.
When switching on the ignition, check for any warning
lights that stay on after the car is started. Pay particular
attention to lights including Airbag, Brakes and
temperature.
The understated lines of the S4 Saloon
When you’re comfortable, take the car for a drive. To
test the car as best as possible, you’ll need at least five
miles of road, including a fast section of motorway.
Ideally you should insist on seeing the car
when the engine is cold – if not on the first
visit, then the next.
Drive the car gently at first until the engine has warmed
up.
Transmission
Check the car in all gears – changes should be smooth
and there should be no sign of crunch or stiffness on a
good manual gearbox, with no signs of the clutch
slipping or snatching.
Turn off the radio and listen. Listen for knocks and
grinds, squeaks and thuds – If you hear any – start
asking questions…
The car should pull smoothly from all gears
and is capable of pulling from 30mph in top
gear without the need to change down a
cog.
A healthy car should cruise quietly and effortlessly.
Push the throttle and you should feel an immense surge,
and no loud sounds of air escaping from the intercooler
or hoses, or whining from the transmission or driveline.
Brakes
Test the brakes – the car shouldn’t dive excessively or
pull to either side, but remain composed through
straights and bends, with a firm pedal feel.

S4 with modified rear braking system
Check for brake squeal, and vibration on the steering
under braking.
Be wary of cars with a spongy pedal feel and
improperly fitted aftermarket brakes.
Electrical
When you are happy that you’ve established a good feel
for the car, switch on the radio, check the CD player
and tape – tune in radio stations, set the air conditioning
to both cold and warm positions, verify the full travel of
all windows, mirrors and all the electrical equipment
that you can lay your hands on.
If the car is fitted with a self-dipping mirror, check its
operation by covering with your finger the forward
facing hole on the right hand side. If it is operational,
you’ll see the mirror darken.
Pay attention to all the switchgear –
especially illumination and cruise control.
With the engine running and the headlights switched on,
close the doors and windows and activate the
windshield washers. From below the bonnet – check
that the “robot” washers push up from the front bumper
and fire at the headlamps.
Get out of the car leaving the windows open – check the
operation of the “closure” system – operating the alarm
and holding down the “arm” button will automatically
close the windows.
The Audi S4 comes highly specced even in
basic form, meaning that it could accrue
potential electrical gremlins.
Remember, anything that doesn’t work and that’s not
covered under warranty will doubtless cost you to
repair.
Engine
The engine is one of Audi’s most modern and advanced
power plants, and as such, you’ll be hard pushed to find
a bad one that smokes and splutters. If you do, walk
away!
From cold, check the oil and water levels. If you find
the oil to be dirty or the anti-freeze to be weak or off
colour (usually a pinky red or greeny blue colour if all
is in order), then insist it is changed prior to purchase.
Start the engine and check for signs of leaks, unusual
noise and fumes.
Ensure that the cosmetics under the bonnet are all
present and undamaged. Look for ring clips that have
been over tightened or have damaged screw heads.
Don’t necessarily be suspicious of a very clean engine
bay, as these cars seem to keep clean of their own
accord.
After the test drive and the engine has warmed up,
check again for leaks, fumes and noises.
Check that there are no severe vibrations in the cabin –
this may suggest signs of worn engine mountings, or
poorly fitted exhausts in the case of modified cars.
Interior
With the exception of the Leather Alcantara
combination, the interior of all S4s is durable.
Alcantara although a strong man-made fabric, is prone
to staining and marking, and requires a great deal of
discipline to keep it clean and looking good.
All cars are fitted with a three-spoke leather steering
wheel and leather gear knob.
Sound system is in the shape of Audi badged
Symphony, Concert or Full Navigation systems
featuring a TFT screen.
Later vehicles were offered with the option
of electrically adjustable front seats and
recaros.
The S4 in base form is well equipped

Be wary of cars with poorly fitted aftermarket mobile
phone cradles, turbo gauges and stereo equipment.
Cars fitted with pearlescent paintwork,
sunroofs, BOSE audio and leather or
leather and alcantara combinations usually
command the highest prices.
Severe marks or holes in plastic trim can be costly to
repair and due to the overall high build quality of the
car, can be time consuming to replace resulting in hefty
bills.
Again, check that everything works – open the sunroof,
check the operation of the heated seats and the
ventilation. Check that the fine “fins” in the air
conditioning vents are not broken or damaged. Sit in
the back of the car and examine the headlining and map
pockets on the back of the front seats.
The car comes with four keys – two housing the remote
device for the alarm, a valet key which doesn’t open the
glove compartment, rear seats (saloon) or boot lid, and
an emergency wafer thin key that fits into a purse or
wallet. Make sure you have them all and ask the owner
if they have any copies that they need to give to you.
Check that the main keys operate all locks, including on
the saloon the locks for the fold down seats in the rear.
Examine the condition of the main keys, looking for
any cracks or tears in the plastic. Walk a distance away
from the car and check that the remote on the main key
will lock and open the car from at least the distance of a
couple of cars away – this will determine the condition
of the battery in the key.
Always be courteous. If you find a vehicle
you don’t like, explain politely to the owner
that it’s not quite what you’re looking for
and walk-away…
Ask the owner to show you the Radio and locking
wheel bolt codes. If they are unable to do so and
suggest that the dealership knows the codes, check with
the dealer before you commit yourself to any purchase.
Screening
In this day and age of uncertainty with high insurance
premiums, theft at an all time high and unscrupulous
individuals “ringing” and “chopping”, “cutting” and
“shutting”, you’ll want to know that the car you are
buying is not stolen, that it’s not an insurance write-off
and that it’s safe and poses no danger to you or your
friends and loved-ones.
In the US, and the UK, it’s possible to approach
agencies like www.Carfax.com and www.HPI.co.uk,
who check the history of vehicles nationwide.
Vehicle History Reports can reveal
important background information and
unearth hidden problems in a vehicle's past
which may affect its safety and resale value.
They can reveal using the seventeen-digit Vehicle
Identification Number the following types of risks:
• Totalled in an accident or salvaged
• Flood damage
• Odometer rollbacks
• Lemon histories
• Emissions inspection results
• Lien/Finance activity
• Vehicle usage (taxi, rental, lease, etc.)
Before you purchase any vehicle, it’s always wise to
use such an agency to verify the authenticity of your
intended purchase.
Ensure you are comfortable before committing to any deal
A time to buy…
After you’ve researched a vehicle to your satisfaction,
you’ll now be in a position to make the transaction.
When you visit the car, check that it’s in the same
condition as when you last saw it. Check that the
owner hasn’t removed anything essential such as tools,
decals or what was originally interpreted as part of the
deal. Check that the tyres haven’t been swapped or
changed and that there has been no new damage
sustained since your last inspection

Buyers Checklist
On the next page, you’ll find a buyers checklist
detailing all the points you’ll need to cover when you
visit a prospective car.
Check with the owner before you visit that they have
time for you and are not in any hurry to dash of to take
the little one to a school play or grandma to the hospital
during your visit.
Take your time – don’t be rushed or
pressured into doing anything you are not
comfortable with. A major part of buying
any car is careful preparation and
homework.
Ensure that they have all the paperwork needed and that
you will be able to start the car from cold when you
arrive.
Agree on a preferred method of payment in advance
Do take some sort of ID with you to reassure the
potential seller that you are genuine. If possible, go
with a friend – never with more than two or three
people in total. If you can – take someone with you
who is knowledgeable about cars.
If you don’t feel happy about carrying out
an inspection, take an expert with you.
Remember, the checklist is a guide to assist you in
deciding whether a car is worth buying. If you find
yourself answering “Yes” to a lot of questions, it may
be best to make your excuses and walk away.
While completing the checklist, bear in mind the
following:
Exterior
• Look for unmatched paint or poor body fit
(may indicate collision damage).
• Check for body filler (use a refrigerator
magnet wrapped in tissue paper on suspicious
spots).
• Look for signs of rust, especially at wheel
wells, under doors, in the boot (trunk).
• Musty smell or dampness in the boot may
indicate collision damage.
• If car appears newly painted, ask why.
Tyres
• Wear should be even on each tyre and among
the set.
• Tires should be the same size, rating and
preferably the same make.
• Wear should be consistent with odometer
mileage.
• Insist on a spare, jack, and wheel brace if
they’re missing. Check for the locking wheel
key.
Suspension
• Push down and release each corner of car. If it
bounces more than once, car may need struts
or shocks.
• Push and pull on each wheel from beside the
car. If wheel moves in or out, bearings or CV
joints may be in bad condition.
• Uneven tire wear may indicate suspension
problems. If car has new tires, be extra careful
in checking suspension.
• Check CV joint boots on either end of front
and rear axles (should be a total of eight). If
torn or missing, you may expect trouble with
replacing expensive joints!
Interior
• Wear of seats, steering wheel, etc. should be
consistent with odometer mileage.
• Pay particular attention to the amount of wear
on pedal rubbers.
• Musty smell or new carpet may indicate flood
damage.
• Make sure windows, safety belts, etc. all work.
• Check glove compartment contents. You
should have an owner's manual. Look for
repair orders that show the car's mileage.
Make sure mileage is consistent with the
current odometer reading.
Engine & Transmission
• Check that all fluid levels are correct.
• Oil should not smell burnt or contain water.
• Coolant should be pinky red or greeny blue,
but not rusty.
• On tiptronic cars, transmission fluid should be
red or pink and not smell burnt.
• Look for leaks around radiator and hoses.
• Spots on the ground under the car may
indicate leaks. To be sure, place a clean
newspaper on ground under the car after
driving it. Check in a few minutes for spots.

Audi S4 Biturbo - Buyers Checklist
Colour Seller’s Name
Interior Seller’s Phone
Transmission Modified?
Mileage Asking Price
VIN Other
Vehicle condition Yes No
1 Is there any sign of rust or damage on the vehicle?
2 Are there any leaks or damaged hoses or belts under the bonnet?
3 Are the tyres and wheels damaged or worn?
4 Are all the seatbelts in good order?
5 Do the doors windows and sunroof show any signs of leakage or damage?
6 Are there any electrical problems? (Dashboard warning, lights, switches)
7 Has the car ever been in an accident?
8 Have any body panels been repaired rather than replaced?
9 Does the car have a good colour match all over?
10 Check the boot (trunk) for spare tyre, tools and damage – anything missing?
11 Has the cars identity been tampered with (VIN numbers)?
12 Is there any damage to the glass on the car – scratches, chips?
Test drive
1 Are the brakes defective?
2 Does the car pull to one side when braking?
3 Do the brakes squeal?
4 Are there any unusual noises or smells?
5 Does the park brake work?
6 Does the steering wheel shake or vibrate?
7 Does the car pull to one side?
8 Is changing gear difficult?
9 Does the gear lever jump on acceleration or braking?
10 Does the clutch slip or snatch?
11 Does the engine sound different when the clutch is pressed on idle?
12 Is there a strong smell of petrol, oil or brake/clutch lining?
Post test drive
1 Doest the engine rattle or make other noise?
2 Are there water or oil leaks?
3 Is there any smoke from the exhaust?
4 Has the car been clocked? Has the instrument cluster been tampered with?
5 Is there any heavy wear and tear signs that are inconsistent with mileage?
6 Does the mileage on service documentation contradict the odometer reading?
7 Are any of the four keys missing?
8 Does the sound system exhibit any faults – CD & Tape?
9 Does the interior require any repairs?
10 Are there any poorly fitted modifications?
Use reverse of sheet for additional notes and observations