The C4 Audi S4 / S6 (UrS4/S6) Buyer’s Guide, 2010 Edition

Along with our new web site, the time has come for another revision of our long standing buyer’s guide for the first generation S4 and S6 model cars.

A lot has changed since I first wrote a buyer’s guide for these cars many years ago. Many (many) more miles have accumulated o­n the cars and age has taken a toll o­n them as well. Does this mean that the cars are no longer looking for o­n the used car market?  Not really! Quite the contrary in actuality.

Many of these cars are bargains these days as far as I am concerned. While our guide applies primarily to 1992-1997 North American model S4/S6 cars, it can also be useful for owners of European specification models.

UrS4If you are contemplating the purchase of a first generation (C4 chassis) Audi S4 or S6 then you’re obviously someone who has an appreciation for understated sport sedans. Part of the attraction of these cars aside from the rarity factor is that they are extremely comfortable and capable sport sedans that don’t typically scream “Hey look at me!”  They are also, for the most part, simple enough to work on for the average enthusiast.  While some aspects of the cars are best left to the professionals, a number of things can be done yourself making them more economical to own that the newer uber sedans.

Before beginning we should explain the ‘Ur’ prefix we often use when referring to these cars. Simply put, “Ur” is a German prefix meaning original. You’ll hear these cars referred to as UrS4/UrS6 or the original S4/S6. We’ve now seen four generations of the S4 platform yet there is still a core group of enthusiasts that swear by their UrS4/S6 cars. These cars are unique. Special. Limited production. Oh yeah, and they can be quite fast as well!

With that out of the way let’s take a closer look…

So where did the S-Cars come from anyway?

Germany of course! Historically speaking, the first generation S4/S6 models owe their existence to the hugely successful Audi Sport Quattro rally cars. After all, the 20 valve turbocharged five cylinder AAN engine found under the hood (bonnet for those of you across the pond) was developed and proven via the Audi rally program. Naturally, the engines found in the original Sport Quattro rally cars are not identical to those found in the average S4/S6 street car but the lineage is there. In fact, the Audi 200 20 valve with the 3B code engine was the first Audi sedan to be graced with the rally inspired engine. The combination of a capable 20 valve turbocharged engine, (which in the case of the 200 20V produced 217 HP) and a well equipped sport-luxury sedan was quite a hit. The cars received praise from the motoring press but the then sluggish U.S. economy combined with Audi’s then dismal sales figures meant that few of the cars were sold during 1991.

The S4 is born….

In 1992 Audi came back with a revised package for the venerable 20V turbo five. New for ’92 the AAN engine featured individual coils for each cylinder rather than the distributor and plug wires found o­n the 1991 Audi 200 3B engined cars. This enhancement helped boost horsepower from 217 to 227 horses. Performance was excellent for a moderately sized sport sedan. 0-60 MPH sprints required roughly 6.3 seconds which at the time was quite impressive (even today it is quick by sedan standards.)

Exterior visual enhancements included flared front fenders, 16×8” five-spoke forged Fuchs alloy wheels shod with 225/50-ZR16 rubber (later replaced by cast alloy 16×7.5” AVUS wheels o­n some S6 models) , ellipsoidal halogen headlights, and a slightly more aggressive stance than the standard issue 100/A6. Pearlescent white paint was the o­nly exterior option aside from the uber-rare sunroof delete option.

Inside the car potential buyers were treated to Recaro sport seats up front, heated seats front and rear (U.S. models), Audi/Bose sound systems, and pretty much every other creature comfort you might need including a hands-free cellular phone mounted in the center armrest. A 10 disc (6 disc o­n later cars) was the o­nly interior option. (Technically, a sunroof-delete option was also available for drivers seeking more headroom but to date I know of o­nly o­ne such car here in North America which is in the hands of a Canadian enthusiast.)

Once again the motoring press praised the Audi uber sedan… not o­nly for the performance but also for the price in comparison with competitors BMW M5 and Mercedes E400. The S4 did still cost nearly $50,000 U.S. dollars (1992) and the economy still wasn’t exactly booming. Audi dealers sold roughly 250 examples the first year and a little more than 500 in 1993 and following years. o­nce the word was out o­n these cars they became very difficult to find o­n dealer lots. I recall my father’s efforts to purchase a ’93 S4 during the summer of ’95… just as soon as the dealer would take o­ne in o­n trade it would be sold. It took nearly six months to find o­ne! Luckily, they are available o­n the used vehicle market these days and at bargain prices.

Buying a 1992-1997 Audi S4 or S6…

UrS4The time has come to buy your own 1992-1994 S4 or 1995-1997 S6? As these cars have gotten older, there are some additional areas that should be closely inspected when looking to acquire such a vehicle. Generally speaking, these cars were among the most reliable ever built by Audi and they remain great cars for daily service. Proper maintenance is the key to finding the right car.

All things get older and the S-Cars are no exception. The question is, do the original S4 and S6 models age gracefully or do they turn into nightmarish wrecks needing constant attention? Simply put, the vast majority of S-Cars remain solid and reliable despite the years and many many miles. The current market values for these cars make them a nearly unbeatable bargain in the four season family sized sport sedan category. The combination of size, luxury, and performance wrapped up in somewhat of an understated performance sedan package makes them enticing even against more modern Audi offerings.

A good S4/S6 candidate car would be o­ne with a full compliment of service records and an owner who appreciated the car. For this reason, buying a car from an enthusiast owner, such as an S-CARS.ORG member, would be a good place to start. Just remember that few cars are 100% perfect, so don’t expect perfection no matter how nice a car looks or sounds. It is normal to have a few things that need to be taken care of. Don’t let it scare you away from a car if everything else checks out. If the car you’re looking at has more than a few minor problems, make sure the price reflects it. Be very cautious if the car has any major problems (i.e.: transmission trouble, bad A/C system, power steering rack failure, or significant accident damage) Minor fender benders are probably OK as long as repair work was carried out by top notch professionals and there are no signs of rust or paint bubbling.

Now we’ll examine the cars more closely…

Body Structure:

All C4 chassis cars were double galvanized by Audi therefore body panel rust is generally not a major concern unless the car has been in an accident and improperly repaired. Areas more prone to rust include the wheel arches (specifically the bottom trailing edge of the front wheel arches) and the rear trunk lid above the license plate and under the taillights. Generally rust in these areas is limited to surface rust that can be managed. It should also be noted that the hoods (or bonnets) o­n many S6 models were prone to rust along the outer edges of the hood. This was an issue that manifested itself fairly early, so many were replaced by dealers under warranty. Check this area closely if you are considering an S6 model (and don’t overlook it o­n an S4).

Another area to check is the area where the steering rack is attached to the body of the car. In some cases, owners have reported cracks in the structure where the rack mounts. A creaking sound in the steering can be a hint that all is not well here. This issue was most likely found in the S4 and some early S6 model cars. Later S6 models had reinforced body structure at this area so perhaps Audi caught o­n to the potential for cracks developing here. This problem CAN be fixed in most cases. There is an F.A.Q. o­n the site that details the steps taken by o­ne owner.

The paint o­n these cars was high quality although the Tornado Red and Black cars would tend to oxidize a bit if not religiously maintained. I have seen some clear coat cracking o­n cars as well. If properly cared for, the original finishes o­n these cars can still look very good after the years. You will likely have some rock chips along the front edge of the hood and front fender flares. Watch for acid rain damage o­n cars from the Northeast and more severe rock chips o­n the cars from the Rocky Mountain region such as the Denver metro area. It is not uncommon to see NE and Rocky Mountain region cars with repainted front bumpers, hoods, front fenders, or mirrors due to this road rash. Make sure that any paint work was for cosmetic reasons rather than accident damage. Obviously you will want to make sure the repaint looks to be of good quality as well.

Cars from the Northeast and Midwest and other “winter salted” areas of the country will likely have considerable rust o­n the fittings underneath the car. In most cases this just makes them less convenient to work o­n but it can be a cause for more serious concern in terms of brake calipers or fuel lines. We’ll detail these issues in another section.

What to look for…

– Check all door and fender gaps closely for signs of panel replacement or repair. The gaps should all be uniform with no signs of overspray.
– Carefully examine the steering rack mounting points under the hood and in the front wheel areas. Some owners have experienced cracking in this area. It can be fixed but is best avoided.
– Check the seams along the edge of the hood for signs of rust. This problem was more common o­n S6 models and was often repaired/replaced under warranty by Audi.
– Wheels arches are prone to rock chips. The trailing edge of the front fender seems to be especially prone to damage and can start rusting if not properly cared for.
– Inspect the fuel lines under the car, especially at the points where they pass through the rubber mounting block with stainless clips. Water and road debris tend to collect at this points and may cause the fuel lines to corrode and eventually leak. This problem is most prevalent in the northeast and other “salted” areas of the country. Replacement lines can be obtained from an Audi dealer but they are by no means inexpensive.
– Bumper covers should be in good shape. Beware of covers with cracks or holes in them. Replacement bumper covers can be a bit difficult to locate and typically cost upwards of $600. Bumper covers that “sag” o­n the trailing edge likely have broken side mounting clips. Sometimes you can get lucky and pop them back in place. The majority seem to need new side mounts. Replacement side bumper mounts are not very expensive although often times it is the mounting point o­n the bumper cover itself that has cracked. You’ll have to do your own MacGyver (creative) repair o­n these unless you want to spent a lot of money and buy a new bumper cover.

Engine / Driveline:

The 2.2 liter 20 valve inline five is a time tested work horse that appears to have no set “expiration date”. There are many cars still o­n the road with more than 200,000 miles. Even more surprising is hearing how many of these high mileage cars still have the original K24 turbo working nicely!

Transmissions: All cars sold in North America were equipped with a 5 speed manual gearbox. Unfortunately, the early model cars had problems with pinion bearing failures which often resulted in a high pitched whine that would increase/decrease with speed regardless of whether the clutch was in or out.

Turbochargers: The original K24 turbochargers have performed very well in the long term. Even in Stage 1 or 2 chip tuned cars, these turbos were capable of racking up many miles of service. o­ne of the common upgrade turbos for these cars was the Porsche/Audi RS2 turbocharger. These turbos are even more robust than the K24 units and assuming proper care and engine software they should not be problematic.

What to look out for…
– Transmission noise: If the car you are looking at makes a whining sound that increases or decreases with vehicle speed (regardless of whether the clutch is engaged or not) it likely has a problem.
– Smoke from the exhaust o­n start up: o­n higher mileage cars, this is likely a sign that the valve guide seals have some wear. A small puff of smoke o­nce in a while o­n start up isn’t cause for major alarm but if you get substantial smoke each time the car is started or while driving there are more serious issues.
– Turbochargers: o­n a stock K24 car (engine cold) remove the intake hose o­n the front side of the turbo. You should be able to stick your thumb and index finger in to grasp the center shaft of the turbo wheel. Gently check the turbo shaft for excessive movement fore/aft or up/down. If it feels loose the turbo is likely getting close to needing a rebuild or replacement. “Tired” turbochargers often make more noise while driving under boost conditions as well. Really tired turbos may blow smoke out the rear of the car while driving.

Suspension / Wheels / Brakes:

The stock suspensions o­n the North American S4 and S6 were far too soft for many enthusiast owners. As a result, it will not be uncommon to see cars with Eibach or H&R lowering springs and sport shocks. This is not necessarily a bad thing unless you live in an area where roads are unnervingly harsh. The H&R springs are typically firmer riding than the Eibachs, so keep that in mind as well. Suspension bushings and bits don’t last forever, so by now most should have been replaced or upgraded. Be aware that o­nce these cars are lowered with either the Eibach or H&R sport spring kits, they will no longer be alignable to factory specs. You will need to purchase some adjustable camber plates from ECS Tuning in Ohio or 2Bennett in California to alieviate this problem. Another alternative would be to modify your existing plates via the Igor Kessel camber plate mod which can be found elsewhere o­n our web site.

The stock wheels for the UrS4 were 16×8” forged Fuchs (pronounced: “fooks”) five spoke alloys shod with 225/50-16” tires. The Fuchs wheels were generally strong and fairly light weight compared to aftermarket wheels. The clear coat o­n the lip of the wheel was prone to cracking and discoloring… especially o­nce the wheels had come into contact with a curb or other abrasive surface.

An optional six spoke 15×7.5” wheel made by Speedline was also offered by dealers in the snowy parts of the country as part of the all-season option. These wheels were often shod with 205 or 215 series snow tires for winter use.

Finally, the later model UrS6 and all UrS6 Avants were fitted with the AVUS style 16×7.5” cast alloy wheels. The AVUS styling of these wheels is something that has been carried over in some shape/form to the latest model offerings from Audi.

’17″Larger wheels and tires are not uncommon sights o­n UrS4/S6 models. Most owners opt for 17” wheels with tire sizes ranging from 225/45-17 to 255/40-17 depending upon wheel width. Keep in mind that larger wheels typically mean more weight and rotational mass which can affect your acceleration and braking. Lightweight plus size wheels such as the OZ Superleggera, SSR Competition, and other forged or light weight wheels are icing o­n the cake. Many big brake upgrades REQUIRE that 17” wheels be used in order to safely clear the brake calipers.

Got brakes?
Perhaps o­ne of the biggest areas of disappointment for owners is in the stock brake system. The North American model cars were fitted with Audi’s long used Girling G60 brake calipers. These brakes are certainly sufficient for stock street use however they are not well suited to track use where repeated high speed braking is the norm. As a result, you may encounter cars with upgraded front brake calipers and rotors. The most common upgrade path uses the Porsche/Brembo 4 piston calipers from cars ranging from the Porsche Boxster o­n up to the Porsche 993 and 996 twin turbos and every model in between. The Porsche 993tt/996tt “Big Reds” as they are often called are generally the most desired models with front wheel brake upgrade kits costing roughly $2500. It is obviously a nice “bonus” if the car you are looking at has been fitted with these uber brakes.

Interior Systems:

While the UrS4 and UrS6 had all the bells and whistles of the era, they are relatively simple in comparison to the more modern models.

What to look out for…
– Instrument cluster and switch bulbs: More of a nuisance than anything. These bulbs can be replaced with relative ease in the instrument cluster and climate control head for the do-it-yourself types although the switch illumination bulbs may require some soldering in tight spaces to replace. The good news is that the bulbs are relatively inexpensive and many owners opt to replace them with slightly higher wattage units (there is an FAQ o­n how to do this elsewhere o­n this web site.)
– Climate Control Units: It isn’t uncommon to see burnt out bulbs behind some of the buttons or LCD panels. This can be easily fixed with some new bulbs. Watch out for bad LCD panels however. If the car you are looking at has a scrambled display or missing segments make sure you can either live with it or afford to replace it (~$400). It should also be noted that the original amber color display units found in the earlier UrS4 model cars is no longer available from the dealer. Audi o­nly sells the later style units with more of a reddish color display. The later display type will work but be aware it won’t be a perfect match with the rest of your interior lighting.
– Heater flap motors: Check to see that the climate control functions for changing from the dash to floor vents and defrost work OK. It should be obvious if the flap is not working.
– Bose audio systems: Generally pretty reliable in the UrS4 and UrS6 but there can be problems with the volume knobs and buttons. It is not easy to simply add an aftermarket head unit to these cars due to the Bose amplified speakers.
– Accelerator pedals: Yeah, they can and do break from time to time. (That will teach you to stomp o­n the gas so hard next time huh!?) A replacement can be had for about $80 USD.
– Power seat motors: Not generally a problem area o­n these cars but I’d bet they aren’t cheap to replace. More often than not, a problem might be in the power seat switches themselves.
– Heated seats: The majority of North American cars have front and rear seats with the exception of a few cars with o­nly heated front seats (generally Canadian models.) The heating elements within the seats can fail leaving you cold in the winter. A tell tale sign of a seat that is about to fail is a “hot spot” usually near the driver side bolster. Failed seat heating elements can often be repaired by removing the seat covering and finding the broken part of the element then soldering back together. This may prove to be o­nly a temporary fix however, so you may as well order a new seat heating element (~$100) and replace it entirely. It might be best to leave this work to an auto upholstery shop if you’re not comfortable tearing apart your seat.

Performance Enhancements:

To some, buying a car with performance upgrades is a good thing while to others it is something best avoided. Let’s put it this way, if you intend to purchase a stock vehicle and then perform a bunch of modifications yourself then I would suggest looking for a car that already has some of the upgrades you seek. Why, you might ask? Simple economics! Given the current exchange rates (USD to EUR) many of the common performance upgrades have become more expensive than ever before. Parts such as the RS2 exhaust manifold which could o­nce be had for around $700 now demand upwards of $950 from most sources. (Granted, this is not all exchange rate influenced… part scarcity also comes in to play since there were not an infinite number of these manifolds produced.)

Just be sure that the car you are buying has been properly upgraded and maintained. If you have questions regarding the upgrades o­n a car you’re considering purchasing, feel free to drop us a line.

What changed o­n these cars from year to year?

Taking their cues from Porsche perhaps, Audi had a tendency to make subtle changes from year to year o­n these cars. Generally speaking, the changes were not typically significant save for a few notable exceptions. A list of year to year changes can be found here.

OK, so what breaks / fails o­n these cars and how much does it cost?

While these cars are generally quite reliable (assuming they have been well cared for!) there are some things to be prepared for as with any automobile.

ENGINE
• Camshaft position sensor ($200 + ~ 4 hrs. labor)
• Ignition coils ($140 each, 40 mins. DIY)
• Power Output Stage (~ $200)
• Oxygen sensor ($40 for splice-in / $120 original, 20 mins. DIY)
• Rear brake calipers ($220/side + 1.5 hrs. labor)
• E-brake cables
• Lower door trim ($45 per piece, installs in minutes DIY!)
• Washer reservoir ($60 + 1 hr. labor DIY)
• Coolant reservoir ($70 + 1 hr. labor)

So how much should I pay?

Generally speaking, the majority of the nice cars I’ve seen for sale sell for between $3,800 and $18,500 USD. Early models and higher mileage examples can often be had for as little as $3,500, but don’t expect a car that “needs nothing” at that price. Generally, a very solid daily driver car in good condition with good service history can be had for around $9,000. The values of these cars are all over the map so the Blue Book or NADA values often go out the window. It is getting harder and harder to find really nice cars, so don’t be afraid to pay a little more for that perfect car if you should come across o­ne in your search.

Note: Last revised: September 22, 2010

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