10 Used Audi Models With Potential Reliability Issues

Audi has a reputation for reliability that's recognized the world over, so how did these problem models slip through?

Just because a brand like Audi has a great reputation for building solid and dependable cars, it doesn't mean all models are totally bulletproof – and the 10 cars believe prove this case quite clearly.

They're not hideously unreliable (well, some are actually) but they do have the potential to give you some stresses over reliability, be it through lack of maintenance, which is always a risk when shopping for used cars, or simply because they have some frustrating common issues.

Let's take a look at some of the more troublesome models from not only the German brand's past catalog but also some current offerings too.

Expensive maintenance is given with high-end cars like the Audi R8, but that doesn't mean you should also expect unreliability – however, that's exactly what you get when purchasing a used first-generation Audi R8.

One big bill is the air-compressor pump, which is cramped deep down underneath the mid-mounted V8 or V10 lump, and as such gets no airflow, making it all too easy for the pump to overheat. Replacement units are highly expensive, but that's not the issue here – the rear end of the car and engine both need to be removed to replace the unit, so labor costs are understandably extortionate.

Related: 8 Reasons Why The Audi R8 Spyder Is The Perfect Supercar For Gearheads

Let's wind the clock back even further and consider one of the first RS models from the brand and one that paved the way for some super-successful models since – we are of course talking about the venerable Audi RS6!

These models are now modern classics, and after two decades of hard driving, most of them have some surprising bills to spring upon new owners, such as failing torque converters that cost $5,000 to replace, or tired brakes that will set you back $1,500 each time (thanks to the huge power, the early RS6 will demolish consumables like these in no time!).

While they are an attractive proposition, especially at current prices, you'd better have some savings behind you if you're contemplating one of these beasts for the daily duties.

While the aforementioned R8 and early RS6 both have their issues, they are still super-cool cars that any driving enthusiast should be excited about owning - unfortunately, we can't say the same about the old Audi Allroad.

It's tough to know where to start – from failing electronics, faulty gearboxes, and constantly troublesome air suspension, the Audi Allroad is a money pit in waiting for anyone brave (read stupid) enough to consider owning one. The air suspension is a constant nightmare for owners, and it's not even easy for them to diagnose, because failures can crop up in the struts, lines, or the compressor itself!

This is one model best left in the history books, sorry Audi.

We're tempted to say this same about this next model too, but it does have some redeeming qualities; if we're being specific, it actually has twelve redeeming features, and funnily enough, they're all cylinders!

The bonkers V12 Q7 is a stupendous feat of engineering that serves absolutely no purpose over the standard model - we should also point out that the almost-as-quick 4.2 FSI model was almost half the cost of this V12 version when new, so no wonder only a tiny number were ever produced.

We won't go into specifics, as it's clear to anyone that a V12 SUV at over 10 years old now is going to cost an absolute fortune every time anything fails, and that's aside from the simply ludicrous maintenance costs these beasts have. Thanks to the crude weight and obscene 493 hp they develop, tires get destroyed almost as quickly as bushes and bearings. Make sure you avoid these unicorn SUVs at all costs.

Related: 10 European Luxury Vehicles That Will Bankrupt You Through Repairs And Maintenance

Coming back down to Earth then, and focussing in on a much more mundane SUV/crossover from Audi – the humble and rather bland Audi Q5.

You'd be forgiven for thinking that this simple Q5 would be simple to run, but the truth is far from that unfortunately – with average annual running costs almost reaching four figures, with RepairPal quoting $928 to keep them on the road on a yearly basis.

Potential issues include EGR and turbo problems, along with fueling and injector trouble, all of which will cost plenty to both diagnose and then resolve, it's best to simply keep clear.

Here's one model that we certainly won't tell you to keep clear of, and that's because it's one of the best driving performance cars of the 2000s! The 4.2-liter V8 is mounted far enough back in the B7 RS4 to keep the weight off the nose, ensuring excellent handling (which we can also thank the sublime Quattro all-wheel drive system for too).

The RS4 does have the potential to cost you with reliability concerns though, especially if you or the previous owner haven't been careful with it. Excessive engine wear is easy to obtain if you don't wait for the engine temp to rise fully, and carbon buildup is an issue on these too, which will lead to rough running and power loss.

The bottom line is, treat them with care and take a preventative approach to maintenance – this way, you're sure to stay in love with your RS4 for much, much longer.

Audi produces a lot of fairly standard commuter cars each year, but they do make some pretty special models too to keep their status as a prestigious manufacturer – the luxurious Audi A8 is one such model.

The flagship sedan has been in production for decades now, and despite the huge costs and impressive specifications, the more recent iterations can leave owners upset with some fairly serious reliability concerns. The third-generation A8 has timing chain rattles, failing electronic handbrakes, and power steering headaches all waiting for excited owners, and as you could expect, this is on top of what is already a fairly expensive car to own and maintain.

Here's a sure-fire modern classic, the very handsome MK1 Audi TT, and specifically the 3.2-liter V6 model which is absolutely the one to go for. Despite being fairly affordable, the V6 model does have its common issues that can be quite expensive, so make sure you inspect it carefully before you buy.

The DSG gearbox needs frequent servicing, so make sure you double-check the history portfolio to see regular services have been carried out because when they fail, they cost thousands to either rebuild or replace.

More common and fortunately cheaper is coil pack concerns, they fail so often that it's entirely normal for owners to carry around spare coil packs in the glove compartment for a swift change when they do go. The last thing you want is your V6 sports car running on 4 cylinders!

Related: 10 Reliable Sports Cars That Are Known For Their Low Running Costs

The Audi A1 caused a huge stir in the automotive world when it was first launched. Finally, there was a cool and premium alternative to the cheaply built and badly specified Corsas, Fiestas, and Clios.

Typically, these smaller cars are owned by young drivers or those who just like to nip around locally, which can be a major concern in the 1.6 or 2.0-liter TDI models. The reason is, the TDI Audi A1s all have DPFs fitted (diesel particulate filters) which easily get clogged up with carbon deposits if no long runs are carried out regularly – this is because the DPF can't get hot enough to burn the deposits off.

This leads to limp mode, engine management lights, and unfortunately huge bills, so make sure you go for a proper run each week if you own one, or you could find a big bill heading your way.

The Audi E-Tron Quattro is only a couple of years old, but surprisingly, customers are already experiencing troublesome reliability concerns – not what you'd expect when spending upwards of $70,000.

There are some annoying issues like reverse cameras going black, or electric handbrakes failing, but these could be the least of your worries. More concerning is the battery issues some people have complained about, as their E-Trons are struggling to charge up to full capacity and are taking the incorrect amount of amps from charging stations - hardly a promising start to the EV campaign!

For now, it's best to stick to conventional petrol or diesel models and give Audi some time to iron out these early reliability concerns in the electric range.

Dan Clougher is a UK based classic car dealer who joined the HotCars team in 2023; as a keen writer, he is excited to contribute and add his touch to the HotCars team. Whilst Dan has a genuine love for anything with four wheels, his true passion is for mid-century, european and modern classics. Having never left the showroom floor since finishing school, Dan always has a keen eye on the used car market, and is never too far from an auction floor.