Engine

COMMON PROBLEMS: Oil Consumption, Timing Chain Tensioner, Carbon Buildup, Oil Leaks, Rough Cold Start

Two things dominate the engine complaints on a Q5. The first is oil consumption, worst on the earlier 2.0T motors, where the level drops no matter how recently you filled it. The second is the timing chain tensioner, and that one deserves respect. A weak tensioner lets the chain go slack, and the tell is a rattle in the first second or two of a cold start. Left alone, it can skip, which is the kind of failure you really don't want. Add carbon on the intake valves and oil seeping from tired gaskets, and you've got the short list we check first.

Cooling System

COMMON PROBLEMS: Water Pump Leaks, Coolant Loss, Thermostat Failure, Overheating, Coolant Smell

Audi's love of plastic is what gets the cooling system in trouble. The water pump housing, the fittings, the thermostat housing, all plastic, and all of it turns brittle after enough heat cycles. Then it cracks and coolant escapes, sometimes as a drip you can see, sometimes as a smell you catch before anything shows on the ground. A stuck thermostat is its own problem, sending the temperature too high or never letting it climb where it should. The reason we push people to catch this early is simple. An overheated Q5 engine is a repair you don't want to pay for.

Fuel System

COMMON PROBLEMS: High-Pressure Fuel Pump Wear, Fuel Injector Issues, Hard Starting, Misfires, Rough Idle

The direct-injection setup is why the Q5 gets the power and mileage it does, and also why the high-pressure pump and injectors work as hard as they do. As they wear, the symptoms tend to arrive together: a longer crank before it fires, an idle that won't smooth out, a misfire that lights the dash and leaves the engine stumbling. Here's the catch. All of that looks a lot like bad coils or plugs from the driver's seat. Chase the ignition side, and you can spend real money and still have the problem, which is why we test the fuel side before condemning anything.

Electrical System

COMMON PROBLEMS: Battery Drain, MMI Glitches, Sensor Faults, Warning Lights, Starting Problems

More electronics means more that can quietly go sideways, and the Q5 has plenty. A battery that's dead by morning usually means something is staying awake and pulling on it after you park. The MMI screen has its own moods, freezing or rebooting when it feels like it. A faulty sensor can drop the whole car into limp mode with no obvious reason. Some of this is easy: a worn battery or a bad ground. Some of it is a module that takes patience to run down. The only way to know is to measure, not assume.

Fresh, the Q5's multi-link suspension is a big part of why the SUV feels as planted as it does. That good feeling fades as the control arm bushings wear, and the first thing you'll notice is usually noise, a clunk over a bump or a knock as you turn into a driveway. The wear does more than talk, though. It lets the alignment drift, which scrubs the tires unevenly and can put a shimmy in the wheel at speed. Ignore it long enough and a composed, quiet SUV starts feeling loose and busy over every rough patch.