Engine

COMMON PROBLEMS: Turbo Oil Consumption, Carbon Buildup, VTC Actuator Rattle, Oil Leaks, Spark Plug and Coil Wear

The turbocharged four in the newer RDX pulls hard, but it can drink oil, so checking the level between changes is worth the habit. Direct injection cakes carbon onto the intake valves over the miles, and that shows up as a stumble or rough running. The older V6 models are known for a VTC actuator rattle, a quick grind on a cold start that owners hear and worry about. Both seep oil from the usual gaskets as they age. Worn plugs and coils bring on misfires and a check engine light.

Cooling System

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

The RDX cooling system holds up well, but heat wears it down over time. The water pump seeps at the gasket as it ages, and hoses and the radiator can start leaking at the seams. A stuck thermostat pushes the temperature the wrong way, sometimes too hot, sometimes never warming right. Half the time you catch the sweet smell before you ever see a drip. Let a slow leak run and it turns into an overheat, and overheating this engine is a much bigger bill than a hose or a pump.

Fuel System

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

The turbo RDX runs direct injection, which helps with power and mileage but leans hard on the high-pressure pump and the injectors. When one starts to fade, you feel it. A long crank before it catches. A rough idle sitting at a light. A misfire that trips the check engine light and leaves the car stumbling. It feels a lot like a coil or plug problem, which is exactly why guessing gets expensive. Testing sorts a fuel problem from an ignition one before you spend.

Electrical System

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

There's a lot of electronics packed into an RDX, and every module is one more place for something to act up. A battery flat in the morning from a drain you can't see. The infotainment freezing or rebooting on its own, which owners report on these. A sensor throwing a fault and dropping the car into limp mode for no reason you can spot. Sometimes it's simple, a tired battery or a bad ground. Sometimes it's a module that needs a real diagnosis instead of a parts swap.

Suspension

COMMON PROBLEMS: Control Arm Bushing Wear, Clunking Noise, Uneven Tire Wear, Steering Vibration, Rough Ride

The RDX rides tight and planted when the front end is fresh, so you notice when it changes. The control arm bushings wear and start talking, a clunk over a pothole or a knock turning into a driveway. Worn parts pull the alignment off too, so the tires scrub unevenly and the wheel picks up a shimmy at speed. Struts fade slowly and let the body float over dips instead of settling. Give it enough time and an SUV that felt sharp starts feeling loose and busy on rough roads.