The crankcase breather of the five-cylinder 2.5 TFSI leads the oil vapour into the intake, and the stub of the diverter valve sits directly next to it. When the diverter valve opens on lifting off, it carries the oil vapour along, and the vapour condenses in the air filter housing, because the stub is right in front of the housing. The oil therefore collects on the filter element and in the bottom of the housing, the amount grows with use, and under load oil mist comes out of the intake pipe as well. The consequence is twofold: measurable oil consumption, and oil reaching the intake speeds up the carbon build-up on the intake valves, which is already heavy here because of the direct injection. This is not a broken part but where the line runs, so it shows up around 40,000 km already, and earlier on a car used hard. The repair is rerouting the breather or fitting a catch can, 200 to 600 euro.

With direct injection the fuel does not wash the intake valves: the petrol goes into the cylinder, not behind the valve. The oil mist and soot arriving through the EGR and the crankcase ventilation therefore build up on the valve stem and head, and from 80,000 to 100,000 km they restrict the flow. Symptoms are hesitation, loss of power, a rough cold start and misfire. It is not a part failure: it is a consequence of the design, and therefore it comes back. Cleaning (walnut or dry ice blasting) helps for a few tens of thousands of kilometres.

Water gets in through the sunroof drains, the door seals or the window guides, and collects on the floor and in the sill. The water also ruins the wiring and the control units in the floor, which leads to hesitant starting and an alarm going off on its own. With a fault like this, lift the carpet first, because the water is under it.

Pixels drop out on the central display of the instrument cluster, where you read the trip computer: the text fades, the backlight becomes erratic, at first one or two dots are missing, and later whole lines are unreadable. This is where the service interval, the outside temperature and the warnings appear, and if a warning is unreadable you will not notice it. The instrument cluster can be refurbished, and a new one is not always needed.

The G62 sensor tells the engine control unit how hot the coolant is. If it is faulty, the control unit thinks a warm engine is cold, and runs it rich: hard warm or cold starting, a rough idle, markedly increased fuel consumption, and a dash temperature gauge that jumps around or never reaches its usual reading. The part is cheap and can be replaced in half an hour: the trouble is that many people do not recognise it and replace an injector or a lambda sensor instead. If the fault persists, the rich mixture can destroy the catalytic converter too.

On the 8P the rubber bushes in the front lower control arms wear out: the steering goes vague, you hear a knock on uneven roads, and the tyre edges wear unevenly. It often shows up around 60,000 to 80,000 miles, which is roughly 95,000 to 130,000 km. On front wheel drive cars the rear suspension bushes wear too, it then rattles, and the back of the car follows the front uncertainly. One part on its own is not expensive, but when they all need replacing together the suspension repair costs more. You can hear it on the test drive and see it in the tyre wear.

The central locking control unit takes in moisture over the years, and from then on it is unpredictable: the doors do not lock together, the remote sometimes does not respond, and the alarm goes off for no reason. A door that stays open is a problem in a car park, and an alarm that goes off on its own can flatten the battery.