An Audi A8 D4 for the price of an ordinary family car? Sounds like the deal of a lifetime, doesn't it? The same goes for the A8 D3, especially if you've spotted a 4.2 TDI with that lovely V8 engine. You get a huge luxury car, quattro, an automatic gearbox and a level of comfort most other cars can only dream of. But there's something people often forget. The price of a used Audi A8 comes down, but the car itself doesn't become any less complicated. Buying one is easy. Keeping it running properly, though, can bring some nasty surprises if you don't know what you're getting into.
Audi A8 D3 or D4 – which generation am I looking at?
First, let's make sure we're talking about the right cars, because you'll come across both generations in the adverts. Both are proper Audi flagships, built to offer maximum comfort, power and technology. That's wonderful when everything works. But once the repairs start, you realise just how many different systems are packed into one car.
- Audi A8 D3 – produced from 2002 to 2010. This is the older generation, so you need to be particularly careful when checking its condition and service history.
- Audi A8 D4 – produced from 2010 to 2017. This is the newer generation, but it still has plenty of complicated systems and needs proper maintenance.
Both generations came with the 3.0 TDI and 4.2 TDI V8 diesel engines, along with V6, V8 and W12 petrol engines. Add quattro and the Tiptronic automatic gearbox, and you've got a fantastic combination on paper. But every one of those systems needs to be in good condition if you want to enjoy driving the car rather than constantly worrying about the next repair.
What are the most common Audi A8 D3 and D4 problems?
Why does the air suspension sag?
Air suspension comes as standard on the Audi A8, and it's one of the reasons the car rides so beautifully. Instead of ordinary springs, you've got a system that uses air to keep the car at the correct height. When everything works, you barely give it a second thought. But when the system starts losing air, the car can drop on one side or change its ride height. If you notice anything like that, don't just assume it's normal. I've explained the whole thing in my article about why air suspension sags.
Why are timing chains such a difficult repair?
On the V6 and V8 engines, the timing chains sit at the back of the engine, next to the gearbox. It's one of those engineering decisions you don't really think about while the engine is running quietly. But once the chains start rattling, their location makes the repair much more complicated. That's why I always want to hear an engine start from completely cold before anyone tells me how beautifully it runs. If you want to understand why, have a read of my guides to the 3.0 TDI timing chains and the 4.2 V8 FSI timing chains.
Why does the electronics system show so many faults?
The Audi A8 has loads of electronic control modules, miles of wiring and all sorts of systems that need to work together. And here's something that often catches owners out. A weak battery can make the car behave as though half its electronics have failed. Warning lights come on, fault codes appear, and suddenly everyone's guessing what's wrong. That's why I don't like replacing parts blindly. At Das Auto Service, we check the power supply first, then read the fault codes and find out what's actually causing the problem.
How often should I service the Tiptronic gearbox?
Tiptronic is the automatic gearbox you'll find in these cars. I recommend changing its oil every 120,000 km using genuine oil, or every 80,000 km on the S8. After every gearbox oil change, we carry out an adaptation so the gearbox can work properly. If it's already shifting harshly, banging into gear or jerking, don't assume that changing the oil alone will magically fix it. First, we need to find out why it's behaving that way.
What should I check before buying an Audi A8?
With a car like this, a pre-purchase inspection needs to go well beyond admiring the lovely interior and shiny paintwork. I want to see how the car behaves from cold, whether all its systems work and what the diagnostics tell us. Most importantly, don't rush. Here's where I'd start.
- Check the air suspension in the morning, after the car has been parked overnight. Then see how it behaves over bumps and uneven roads.
- Start the engine when it's completely cold and listen carefully for timing chain rattle. Don't just accept someone telling you that "they all sound like that".
- Test every function in the car and run a diagnostic scan of all the electronic control modules. Just because there are no warning lights on the dashboard doesn't mean everything is fine.
- Check the service history. I want to know what maintenance and repairs have actually been carried out, not just what the seller promises you.
How should I maintain my Audi A8 to avoid expensive repairs?
If you want to enjoy your Audi A8 for years to come, regular maintenance is absolutely essential. Don't wait for something to break before visiting the workshop. Skipping services can have particularly nasty consequences for the engine and automatic gearbox. Here are the main service intervals I recommend.
- Engine oil and all filters – oil, fuel, air and cabin – every 10,000 km or once a year, whichever comes first. This applies regardless of which engine oil you use or what the LongLife service intervals say.
- Tiptronic – change the gearbox oil every 120,000 km using genuine oil, or every 80,000 km on the S8. An adaptation is essential after the oil change.
- Brake fluid – every 2 years. Coolant – every third heating season.
- Preventative inspection – every 6 months, so we can catch problems before they turn into serious repairs.
If you've got the diesel version, I've also put together a separate Audi A8 D4 3.0 TDI service schedule. It'll help you plan your maintenance properly instead of waiting for the car to remind you with another fault code.
WARNING! With an Audi A8, a cheap purchase price rarely means cheap maintenance. Before you hand over your money, think carefully about the condition of the air suspension, timing chains and electronics. Don't let a tempting price distract you from the repairs the car might need.
Is an Audi A8 D3 or D4 worth buying?
Yes, absolutely, provided you find one with a clear service history, good mechanical condition and you've set aside a proper maintenance budget. The Audi A8 is a wonderful car that offers genuine comfort and driving pleasure. But if buying it means spending every last penny you've got, my answer is no. Not because it's a bad car, but because it deserves to be looked after properly. And you deserve to enjoy it without worrying about the bill every time you visit the workshop.
Tip from Kris Mladenov: If you've decided to buy an Audi A8, get a full technical inspection before you commit. To me, that's not money wasted. It's how you find out what you're actually buying. I'd much rather we discover the problems before you buy the car than see you paying to fix them afterwards.
I hope you've found this article useful! If you have, I'd really appreciate you sharing it with a friend who drives an Audi A8 or is thinking about buying one. My mission is simple: when I know something useful, I want more people to know it too. Because good information can save you a lot of trouble and repairs that, in the end, come straight out of your own pocket.
The solution in our shop
Genuine Longlife III FE 0W30 oil 5L
Genuine LongLife III oil is an engine servicing product. What matters is using oil that meets the correct specification for your particular engine and never putting off the oil change beyond 10,000 km or once a year.
View in shopRead more
- Pre-purchase inspection
- Diagnostics
- Audi Air Suspension Problems: Why Does It Sag?
- 3.0 TDI Timing Chain Replacement: Why Remove the Engine?
- Audi 4.2 FSI Timing Chain Replacement: What to Know
- Audi A8 D4 3.0 TDI Service Schedule
Frequently asked questions
How much does it cost to maintain an Audi A8?
It depends on the car's condition, engine and service history. The biggest nasty surprises can come from the air suspension, timing chains and electronics. That's why I recommend a full inspection before buying.
Should I choose an Audi A8 D3 or D4?
The D3 is the older generation, while the D4 is the newer one. Personally, I'd choose the car with the better mechanical condition and a proven service history rather than making my decision based on the generation alone.
How long does the 4.2 TDI engine last?
There's no magic mileage that guarantees how long it will last. What matters is how well it's been maintained, its history and its current condition. Pay particular attention to the timing chains and how the engine runs from cold.
How often should I change the Tiptronic gearbox oil?
On the Audi A8, I recommend changing the gearbox oil every 120,000 km using genuine oil, or every 80,000 km on the S8. We always carry out an adaptation after the service.