Are you looking to purchase a B6/B7 S4? Here is what you need to know!
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.
What to look for before purchasing?
Here i will give a run down on what is necessary to look for / know about the vehicle before purchase.
Maintenance History: Maintenance Documentation is a big thing to look for when buying any used car. Service Records will give you a snapshot of the life of the car and shed some insight on how it was maintained. Always ask for the service records and review what has been done on the car. Check for routine maintenance such as Oil Changes, Filters and other fluids.
Although records are not absolutely necessary, be aware that purchasing a car without them could be risky. You may be getting into something that has not be well maintained, which could results in issues down the road. I would recommend the lack of records be used as a bargaining chip in price negotiation. Go in with the mindset that you will have to do all scheduled maintenance items as soon as you get the car.
Carfax Report: Another big recommendation is to get a Carfax Report on the car. The biggest reason for this is to see if the car has been in an accident. If indeed the car has been in an accident and you are still interested, look thoroughly over the reported damaged area to make sure it was repaired properly and up to standard. Use an accident on the record to negotiate on the price. Usually, cars with an accident are less appealing than a car with a clean history so keep this in mind.
VAG-COM Scan: It is highly recommended to scan the car with a Vag-Com before purchasing. This will give you a list of all of the stored fault codes in the cars computer modules. It is a very useful tool to get some insight on potential problems the car has. The most important module to view is the Engine Module as it deals with all engine / operating fault codes. If you find fault codes, check back on EA to get a diagnosis on what they mean.
Compression / Leak Down: Although not always feasible to get checked, it is a good idea to have these tests done just to be safe. A known issue with these motors is oil consumption due to scored cylinder walls. Having such tests done will give you a snapshot of the health of a motor. Replacing these motors is not cheap by any means. A used motor will run about 3-5k depending on what is included + labor on top of that. Getting a new motor can easily set you back close to 10k all said and done. Don't make the mistake in buying a car that will need major repairs in the near future.
Pre-Purchase Inspection: It is always a great idea to have a third party check the vehicle before purchase. Usually PPI's are very thorough and detailed and worth the extra money to have some peace of mind. Always have an outside dealership or Indy do the work to avoid any biased results. Use any issues or future attention items to negotiate the price.
Maintenance Items: With or without service records, check the following items:
- Request Cold Start: Ask the dealer or seller not to start the car for a few hours before you look at the vehicle. This will give you the chance to listen on start up for Chain Rattle (See Timing Chain Components) and Fuel Pump Priming. If you hear a thudding when turning the key to accessory (fuel pump prime), this will indicate the pump may be on its way out
- Serpentine Belt: Visually check or cracks, tears, or significant wear
- Valve Cover Gaskets: Run a rag along the bottom side or front side of the valve cover. Oil buildup will mean the gaskets need to be changed.
- Coil Packs: Ask if the Coil Packs have been done under recall
- Leaks: If you are able to remove the belly pan, check the underside of the engine compartment for leaks. Oil / Coolant leaks will be visible pretty easily.
- Tire Life: Check the tire life to see how much more time you can get out of them
Fuel Filter: Go to the passenger side rear wheel and listen for any humming or hissing indicating the filter needs to be changed.
Test Drive- What to look for: Here are some items to look for when taking the car for a test drive
- Steering Alignment: Get on a straight road and put the wheel dead center. Look for any pulling or drifting indicating the car needs an alignment. Also feel for any wobble / shaking that would indicate out of balance wheel / bent wheels.
- Control Arms / Steering Rack: Take some turns and listen for any pops / clanks / abnormal behavior from the steering components
- Transmission: Run through all of the gears in different RPM ranges. Make sure the gears shift smoothly and are not notchy. If any automatic, check for any hesitation / bucking during gear changes.
- Brakes: Get on the brakes and feel for any shaking. If the brakes are bad you should be able to feel it throughout the car / steering wheel under braking. Also do a visual inspection when stopped on the brakes. Check the pad life remaining. Also make sure the lips on the rotors are flush with the rotor itself. If the lip protrudes, the rotors will need to be replaced soon.
Interior / Electrical: Check the following items inside the car before purchase
- All Electrical Components: Make sure everything works. Sit there and test every button in the car to make sure it works. Test items such as headlights, dome / map lights, heated seats, radio, navigation (if applicable), horn, windows, etc. You get the idea
- Air Conditioning / Heat: Make sure the AC blows cold air and the Climate Control blows out hot air.
- Glove Box Hinge: Infamous item that breaks on this car. More than likely the hinge will be damaged / broken. Negotiate accordingly.
- Broken Items: Test everything to make sure it is in working order. Play with items such as the cup holder, change drawer, ash tray, etc to make sure everything is working and not broken.
Common Problems / Attention Items
Early B6 Build Date: It is known that some early build dates before (10/03) had some engine/transmission (syncros) 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 starter 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.
Timing Chain Components: One of the big issues that has surfaced in the recent years is wear of vital components in the Timing Chain System. This information is extremely necessary to read before purchasing a B6/B7 S4 because there is a possibility you will have to service the system during ownership. What makes this such a difficult issues lies with the fact that the Timing Chain in this motor is at the rear of the engine. To service most of the components an engine pull will be required. For more information on this subject matter, please follow the link below.
Timing Chain System Discussion & FAQ
Clutch Replacement: Many owners on the board have experienced their clutch to be in need of replacement around 50k miles. This of course depends on how the car is driven. If your clutch goes you will most likely have to replace the flywheel as well. If you replace your clutch before its toast, it will reduce the chances you will need to do the flywheel. It should also be noted that there is a new flywheel design as a result of many previous ones that have failed.
Headlight Condensation for 2005 B6 (Bi-Xenons): The Bi-Xenon's found in the 2005 model are known to have a condensation issue. Dealerships are very tough to get them replaced under warranty. Some members, however, have had luck in getting them changed. Others have used this DIY to eliminate the problem.
Additional Common Problems can be found via the link below. This is courtesy of Jay at JHMotorsports.
Common Problems Continued
There seems to be some confusion with CPO warranties and their transferability. IF and ONLY IF the car was CPO'd BEFORE 8/30/06, the warranty is transferable. In this case the CPO will follow the car until it expires regardless of the number of owners. All you need to do as a new owner is contact AOA and inform them of the change of title, and they will transfer it for you for a $150 fee. All CPO warranties after 8/30/06 are unfortunately non-transferable.
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 of 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.
Cold Air intakes- The Truth
Despite what aftermarket companies try to tell you, the real truth is that cold air intakes are a waste of money for this vehicle. It has been proven again and again that Audi got it right from the factory with their design of their CAI. Save your money and spend it somewhere else. For more information please follow the link below.
Truth about Aftermarket Intakes
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
Mirror Caps: 2004 B6 had aluminum mirror caps, while the 2005-2008 are a plastic aluminum look-alike
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, Cabin 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 perform 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
Serpentine Belt: 1 OEM belt
Around $20 for the belt. Cheap DIY unless you take it to the dealer or indy shop. For the latter expect to pay $300+
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 EA. Prices may be significantly different if you decide to take the vehicle into the dealer/indy shop for maintenance issues.
Arnold Palmer Club Member #1
Some tips please
Joey this post is very useful, I'll be taking this little guide with me when I look at an S4 this weekend.
It's a manual 2004 S4 manufactured (8/2003), clean carfax, has 81K miles and they're asking $12,495. It's a dealership and they don't have the service records for the car. I'll be using your advice on what to look for, but how can I get a visual of the serpentine belt? I'm going to assume it hasn't been changed but obviously they won't let me take off any panels. I'll send pics of the car if it's helpful.
Link to car pics.
Kingman, AZ 2004 Audi S4 4.2 Used Sedan near Las Vegas, NV Lake Havasu City, AZ. Martin Swanty Chrysler Dodge Jeep Kia
I won't be able to get a compression test unfortunately and won't have a way of knowing if it consumes oil. I'll listen for chain rattle on cold start as far as that goes. I heard the car will run and seem normal even with a broken chain guide though, is that true?
Originally Posted by Joey