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The Audi S4 is a luxury sport compact sedan that features a simple but luxurious interior, a powerful engine, and Audi’s Quattro four-wheel drive technology. 

Even though luxury vehicles tend to depreciate more than their non-luxury counterparts, the Audi S4 fares well against depreciation. According to, the S4 will lose 49% of its value in 5 years, which is pretty modest. 

While the S4 may have many features up its sleeve, buying any car comes with its fair share of risks when it comes to reliability. No owner has perfect knowledge about their vehicle’s condition. That’s why in this article, we’ll talk about the experiences of previous owners of the Audi S4 across its 30-year history and identify which models have common problems. 

audi s4 sideshot
The Audi S4 is a luxury sport compact sedan that features a simple but luxurious interior, a powerful engine, and Audi’s Quattro four-wheel drive technology.

Is the Audi S4 Reliable? 

Unfortunately, the Audi S4 doesn’t have a good reputation when it comes to reliability. RepairPal gave it an underwhelming score of only 2.0 out of 5.0. This is below average, according to the website. 

The Audi S4’s annual repair cost is approximately $1,200. In comparison, the average annual repair cost of a sedan is half that. The S4 will also require repairs more often and the chance of those repairs being severe is also higher than the average vehicle. But interestingly, owners expect high annual maintenance costs for the Audi S4 and aren’t bothered by it. This is because most of them purchase the vehicle because of its performance, not its reliability. The S4’s desirability due to its performance could also be the reason why it doesn’t depreciate as much as other luxury vehicles. 

Audi S4 Common Problems 

The S4 is known to have a lot of issues. In this article, we’ll cover the most common problems. Luckily, most of them are minor and can be solved by a simple part replacement. 

Failed Thermostat 

Owners have reported that the 2004 to 2011 Audi S4 can overheat because of a faulty thermostat. The thermostat is responsible for easing or restricting the flow of coolant into the engine, depending on whether the engine is running hot or cold. Instead of opening or closing depending on the temperature, the faulty thermostat would be stuck in either the open or closed position. 

The thermostat plays a crucial role in a vehicle’s cooling system. If ignored, faulty thermostats can cause severe overheats that can result in engine damage. This happened to one owner, who has reported that his thermostat was unfortunately stuck in the closed position, which stopped coolant from entering his engine. The engine damage from the overheat was expensive to repair.

It’s a good thing that the overheating issue is only caused by the thermostat. Replacing the thermostat will fix this problem. You can get replacement Audi S4 thermostats for around $20 to $100. 

automotive thermostat
Some Audi S4 owners have reported overheating due to faulty thermostats.

Turbo Failure 

The turbochargers on some 1997 to 2001 Audi S4 are known to fail. Turbo failures are characterized by a loss in power, a whining noise from the engine, smoke coming out from the exhaust, and maybe a check engine light. 

To avoid this, owners should let the oil heat up and circulate into the components before accelerating hard. This prevents excess wear on the engine and turbocharger. Like engines, turbochargers in modern vehicles are typically expected to last as long as the vehicle. However, their poor design could be the reason why they tend to fail after a few years. A replacement Audi S4 turbocharger costs around $500 to $1,000. 

Engine Oil Leaks 

The 2000 to 2002 Audi S4 tends to leak oil on various engine seals. The most common components that develop a leak are the valve cover gaskets and the camshaft chain tensioner gasket.

An owner has reported that oil leaks from the S4 are quite common. Even though it only has 17 reports on RepairPal, owners should regularly check their S4s for oil leaks. While small oil leaks may be negligible, if your S4’s engine starts dripping serious amounts of oil, then it could be damaged. Replacing the faulty gaskets should stop the oil leak. Replacement valve cover gaskets typically cost around $70 to $120. 

Premature Brake Wear

The 2012 Audi S4’s brake pads have been known to wear out earlier than usual. Even though CarComplaints only has one recorded report, MotorBiscuit reports that around three owners needed to have their rotors and pads replaced prematurely. When one owner needed to have their brakes replaced at 16,000 miles at the dealership, the dealership refused to repair them and merely told them to lay easier on the brakes. Six months later, the owner returned with warped rotors and brake pads worn down to a mere 4mm. 

Replacement brake disc and pad kit can cost as low as $70, but brake disc and pad sets that are made from carbon ceramics can cost up to $500. 

There are many more problems reported by S4 owners on RepairPal. These problems can range from needing to replace oxygen sensors, ignition coils, and spark plugs to strange noises coming from the sedan’s chassis. Luckily, there doesn’t seem to be a recurring problem that’s expensive to repair. Given the number of parts that have been known to show issues, you should inspect your Audi S4s regularly to make sure that there are no faulty components that could lead to bigger repairs. 

Overall, the Audi S4 is a car that constantly needs care and regular check-ups. Unlike most sedans, the Audi S4 isn’t a car that can be neglected. 

If you’re unsure whether an Audi S4 is right for you, we hope knowing about the model’s common problems can help you make an informed decision. While maintaining an unreliable sedan can be costly, sometimes facing a few common issues is worth it if owning a high-performance car can give you a lot of joy.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

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