The AUDI S4 TDI (2019-Present) is an exciting blend of performance, luxury, and efficiency. With its powerful 3.0-liter V6 diesel engine, the S4 TDI offers impressive performance and torque, alongside the refinement and comfort AUDI is known for. However, like any performance-oriented car, it’s not without its potential issues. This article explores the common problems that owners of the 2019-present S4 TDI might encounter, what to check when purchasing a used model, the cost of ownership, and alternatives that might be worth considering if you're after a similarly high-performance vehicle.
Common Problems of the AUDI S4 TDI (2019-Present)
1. Diesel Particulate Filter (DPF) Issues
One of the most common issues in modern diesel engines, including the 3.0 TDI in the AUDI S4, is the Diesel Particulate Filter (DPF) becoming clogged or failing. The DPF is responsible for capturing and storing exhaust soot to reduce emissions. Over time, the filter can become clogged, especially if the car is mostly used for short trips or city driving, where the engine doesn't reach the necessary temperature to burn off the soot.
Symptoms of DPF Issues:
- Warning lights: The DPF warning light may appear on the dashboard, indicating that the filter needs to be regenerated or replaced.
- Loss of power: A clogged DPF can cause a noticeable drop in engine performance, particularly during acceleration.
- Increased fuel consumption: As the engine struggles to compensate for a blocked DPF, fuel efficiency can decrease.
What to Look For:
- Check the DPF status: Ask the seller about the car’s DPF status and whether it has been properly maintained. The car’s diagnostics can show if the DPF has undergone successful regeneration.
- Drive on the highway: If possible, take the car for a longer drive, as this can help to clear the DPF of soot. If the engine feels sluggish or power loss occurs after a short drive, it may suggest DPF problems.
- Inspect for warning lights: Ensure that there are no persistent warning lights related to the DPF.
2. Turbocharger Problems
As a performance diesel, the AUDI S4 TDI relies heavily on its turbocharged engine for power delivery. Although the turbocharged 3.0 TDI engine is generally reliable, issues with the turbocharger can occur, particularly in high-mileage models or if maintenance has been neglected.
Symptoms of Turbocharger Issues:
- Loss of power: A failing turbo can result in noticeable power loss, especially during acceleration or when trying to maintain speed.
- Whining noise: A failing turbo might emit a high-pitched whining or whining noise due to damaged bearings or a compromised impeller.
- Excessive smoke: Blue or gray smoke coming from the exhaust could indicate oil leaks within the turbo system.
What to Look For:
- Test acceleration: During a test drive, accelerate hard to check if the car delivers consistent power. A sluggish response or power loss at higher speeds can be a sign of turbocharger problems.
- Listen for unusual noises: Pay attention to any unusual whistling or whirring sounds, which could indicate turbocharger wear.
- Look for exhaust smoke: If the car emits excessive smoke, it could point to issues with the turbocharger or its seals.
3. Suspension Wear and Noise
The AUDI S4 TDI’s sportier suspension setup provides sharp handling, but it can also be subject to wear and tear, especially if the car has been driven aggressively or frequently on rough roads. Issues with suspension components like shock absorbers, control arms, and bushings can lead to uncomfortable driving experiences and reduced handling precision.
Symptoms of Suspension Problems:
- Knocking or rattling noises: Worn-out bushings or suspension components can cause noises when going over bumps or turning.
- Poor ride quality: A rough, bouncy ride or noticeable instability during high-speed driving can indicate suspension issues.
- Uneven tire wear: Misaligned suspension components can cause uneven tire wear, affecting handling and requiring more frequent tire replacements.
What to Look For:
- Inspect for noises: Listen carefully during the test drive for any knocking, rattling, or clunking sounds coming from the suspension.
- Check the ride quality: Test the car on different types of roads to assess whether the ride quality feels harsh or unbalanced. A smooth, controlled ride is expected from the S4 TDI.
- Tire condition: Inspect the tires for any signs of uneven wear, as this can signal suspension or alignment issues.
4. AdBlue System Issues
The AUDI S4 TDI, like most modern diesel vehicles, is equipped with an AdBlue system to reduce harmful nitrogen oxide (NOx) emissions. The system uses a urea-based solution injected into the exhaust gases to neutralize emissions. Over time, issues with the AdBlue system can arise, particularly if the system runs low on AdBlue or experiences sensor malfunctions.
Symptoms of AdBlue Problems:
- Warning lights: A malfunctioning AdBlue system will trigger warning lights, often with messages related to low AdBlue levels or a fault in the system.
- Performance restrictions: In some cases, the car may limit its engine performance or even enter a limp mode to prevent further emissions violations.
- Poor fuel efficiency: If the AdBlue system is not functioning correctly, fuel consumption can increase.
What to Look For:
- Check the AdBlue level: Make sure that the AdBlue tank is filled and that there are no warnings related to it. Low AdBlue levels can be topped up easily, but sensor failures or system malfunctions can be more costly.
- Look for warning lights: Ensure that there are no persistent AdBlue-related warning lights or messages during the test drive.
5. Electronics and Infotainment System Glitches
AUDI is known for its high-tech interiors, and the S4 TDI is no exception, offering a sophisticated infotainment system with a virtual cockpit. However, some owners have reported glitches and issues with the MMI (Multi Media Interface) system, including slow response times, freezing screens, and connectivity problems with smartphones or other devices.
Symptoms of Infotainment Issues:
- Slow touchscreen response: The MMI system may occasionally lag or be unresponsive, especially when navigating menus or switching between functions.
- Connectivity issues: Problems with Bluetooth, Apple CarPlay, or Android Auto can arise, preventing the car from pairing properly with smartphones or other devices.
- Screen freezes or reboots: In some cases, the system may freeze, or the screen may reboot during use.
What to Look For:
- Test the MMI system: During the test drive, thoroughly test the infotainment system, checking for responsiveness, screen clarity, and ease of navigation. Make sure that all functions, such as Bluetooth and navigation, work smoothly.
- Check for software updates: Ask if the car has the latest software updates, as some issues may be resolved through a software patch.
6. Steering Rack and Power Steering Issues
A handful of owners have reported issues with the steering rack and power steering system in the S4 TDI, particularly in early models. These issues often manifest as stiffness or a delayed steering response, which can be a safety concern.
Symptoms of Steering Issues:
- Unresponsive or stiff steering: The steering might feel heavy or unresponsive, especially at lower speeds or while parking.
- Power steering fluid leaks: Leaks in the power steering system can lead to a loss of fluid, causing steering difficulties.
What to Look For:
- Test steering responsiveness: During the test drive, ensure that the steering is responsive and feels smooth and light, particularly when maneuvering at low speeds.
- Look for leaks: Inspect the power steering fluid reservoir and surrounding components for any signs of leakage, which could indicate a more serious issue.
What to Look for When Buying a Used AUDI S4 TDI (2019-Present)
When purchasing a used AUDI S4 TDI, particularly one that’s still relatively new, it’s essential to ensure that it has been properly maintained and cared for. Here’s what to look for:
- Service History: Ask for a full service history, paying particular attention to any recalls or required maintenance like DPF regeneration, turbocharger inspections, and AdBlue system checks. Routine maintenance should include regular oil changes and timely service intervals.
- Test the Electronic Systems: Given the complexity of AUDI’s MMI system and electronic interfaces, ensure that everything from the infotainment system to the virtual cockpit works properly during the test drive.
- Check for Recalls: Make sure that any recall-related work, especially concerning the engine, emissions system, or safety features, has been completed by the previous owner.
- Inspect for Wear and Tear: Although the S4 TDI is a luxury vehicle, inspect for any signs of damage, excessive wear, or rust, particularly around the suspension components and undercarriage.
How Expensive is It to Own a AUDI S4 TDI?
Owning a performance-oriented car like the AUDI S4 TDI can come with higher running costs than more mainstream vehicles, but it is still relatively reasonable compared to many high-performance petrol engines. Here’s a breakdown:
- Fuel Costs: With its 3.0-liter V6 diesel engine, the S4 TDI offers a healthy balance of power and fuel economy, returning between 35-40 mpg on average, depending on driving style and conditions.
- Insurance: As a premium vehicle, insurance premiums for the S4 TDI can be higher than more common cars, but it’s generally less expensive than high-performance petrol sports cars in the same class.
- Maintenance and Repairs: Routine maintenance on the S4 TDI, including oil changes, brake pads, and suspension work, is relatively affordable. However, more complex repairs like turbocharger or DPF issues can become costly. Always budget for unexpected repairs, especially once the vehicle moves beyond warranty coverage.
- Depreciation: Like all luxury vehicles, the S4 TDI will experience some depreciation, but it typically holds its value better than some competitors due to AUDI's strong reputation for quality and performance.
Better Alternatives to the AUDI S4 TDI (2019-Present)
If the AUDI S4 TDI isn’t quite the right fit for you, here are some alternative models to consider:
- BMW 340d: A competitor that offers a similar level of performance and luxury with a refined diesel engine and excellent handling dynamics.
- Mercedes-Benz C300d: Another high-performance luxury diesel offering, the C300d boasts a similar blend of comfort, performance, and fuel efficiency, with superior interior quality.
- Jaguar XF 3.0d: For those looking for something with a more distinctive look, the XF offers great performance and luxury, though it’s typically less sporty than the S4 TDI.
- Alfa Romeo Giulia Quadrifoglio (Petrol): If you're willing to go for a petrol engine, the Giulia Quadrifoglio offers exhilarating performance and distinctive Italian styling, though it won’t match the efficiency of the S4 TDI.
Conclusion
The AUDI S4 TDI (2019-Present) is an incredibly capable and luxurious car, offering a potent mix of performance, practicality, and efficiency. However, like all high-performance vehicles, it comes with its own set of potential issues, including DPF problems, turbocharger wear, and suspension issues. Buyers should ensure the car has been properly maintained and be aware of the common faults.
If you're looking for a car that combines performance with luxury but are concerned about the S4 TDI’s reliability, alternatives like the BMW 340d or Mercedes-Benz C300d provide similar benefits with potentially fewer issues in the long run.