Okay, the amount of "Im looking into getting an S4..." threads are starting to get rather abundant. This thread is aimed at those looking to get into a B6/B7 S4. I have compiled, with help of other members, general information of the platform, differences between the models, common problems to look out for, and basic maintenance.
If you guys think i missed something please send me a PM or email with additional information where you see fit.
The biggest and perhaps the biggest downfall to the S4 is the fuel consumption. However, what do you expect driving a V8? Here is what to expect.
Tank Size: 16.6 Gal
Average Per Tank: 200-250 Miles*
*This number will not be true for every individual. As we all know the MPG and Miles Per Tank all depend on your driving style. If you are conservative and drive mostly highway, you can expect low to mid 20s. If you are on the opposite side of the spectrum and drive the car hard, expect mid teens.
Naturally Aspirated Motor vs FI
One of the big misconceptions of individuals looking at the B6/B7 deals with the tuning a N/A motor. To get straight to the point, the B6/B7 S4 is not a tuner car compared to the B5 platform. This car is a 4000 pound SEDAN, as much of a luxury car as it is a performance car. If you are looking for a car that you can make run 10 second quarter miles times with a minimum amount of money, then this car is not for you. There are several companies out there, such as JHM, that have made huge advances in the B6/B7 platform. These companies are making it possible to squeeze as much power out of this N/A motor as possible. However, as stated before, do not expect to get significant powder gains unless you are looking to go forced induction.
We now have our own WIKI for the B6/B7 S4/RS4. Additional information about the platform can be found by following the link below.
B6/B7 S4/RS4 Wiki
Early B6 Build Date: It is known that some early build date S4's (8/03) had some engine problems. Those problems should have occurred by now or have been fixed/replaced. Although it is a relatively big concern when purchasing a car, be aware that not all of the early builds had problems. The ones that did should of/have been fixed by now. If you are that concerned with an early build S4 either looker for a newer one or purchase and extended warranty.
Coil Pack Failure: One of the most common issues with the B6/B7 S4 is a coil pack failure. This problem can be identified by a CEL/Flashing CEL accompanied by mis-fires and a hard idle. Coil packs cost around $30 each new. If your coil packs fail under warranty they will be replaced by the dealer.
Common Engine Codes for a Coil Pack Failure:
16684 - Random/Multiple Cylinder Misfire Detected
16686 - Cylinder 2: Misfire Detected
Starter Issues: There are several cases where the started has gone on the S4. You can most likely detect a bad started while turning the key to start the car, NOTHING will happen. Is you do not have a warranty, this can be a rather expensive repair.
Additional Common Problems can be found via the link below. This is courtesy of Jay at JHM.
Common Problems Continued
Differences Between B6/B7 S4
Mechanical/Electrical - Thanks to Jay at JHM
Flywheels: A B6 flywheel only works with a B6 Pressure plate and the same with a B7, they bolt up to either motor though.
Clutch Pressure Plates: A B6 pressure plate only works with a B6 flywheel and the same with a B7
Intake Manifolds: The B6 S4 has a nice gray coating on top and the B7 S4 has a temperature resistant coating underneath where it is closest to the motor.
Core support to motor clearance: The B7 S4 has about 1 to 2 inches more room of core support to motor clearance than the B6.
Center Differential: The B6 S4 and the 05.5 B7 S4 only share the same center differential. The 2006 and up B7 S4 and RS4 share the same center diff.
Appearance and Options
2004-2005 = B6 Body Style
2004 vs 2005 Difference
-GPS Antenna: Notice the 2004 below (left) is larger than the 2005 (right).
-Xenon Headlights: Single Xenon Headlights (2004) vs Bi-Xenon Headlights (2005)
-Engine Covers: 2004 Side Engine Covers Included vs 2005 Side Covers were not included
2005.5- 2008- B7- New Updated Body Style
Below is the Audi recommended service schedule for maintenance.
Please note that some maintenance items should be changed sooner if they are failing/and or they appear they need to be replaced. Such items include: Valve Cover gaskets, Air filter, Pollen filter, Fuel Filter, Spark Plugs, Serpentine Belt Etc...
The wonderful Audi community here has put together a large amount of DIY's to assist owners in performing their own maintenance. These step by step guides help even the least mechanically capable owners in performing their own maintenance. If you still need help while following the DIY's, there are many members here to assist you by answering questions or giving their advice.
B6/B7 S4/RS4 FAQs and DIYs
Cost: Basic maintenance on the B6/B7 S4 is not one of the cheapest vehicles to own. Please be aware of this while considering your purchase. Below is an example of what to expect if you are going to maintenance by yourself.
Oil Changes: 9.5 Quarts Ow40/5w40 + Oil Filter
- Expect to pay anywhere from $80-$120 depending on your choice of Motor Oil and the Oil Filter
Spark Plugs: 8 Plugs
- Expect to pay around $50+ depending on the spark plugs you choose. Plugs for this car range around $6-$7 per plug.
Air Filter: 1 OEM or Aftermarket Filter
- Expect to pay around $20-$25 on an OEM filter
Valve Cover Gaskets: Both Gaskets + Half Moon Seals + Coil Pack Seals
- Expect to pay anywhere from $60+ for a complete set. Price varies by dealer and retailer
There is just a general feel for the price of common maintenance items. Please note that those prices are for those of you that decide to DIY. All procedures have been documented here on Audizine. Prices may be significantly different if you decide to take the vehicle into the dealer/indy shop for maintenance issues.