The turbocharged engine behind the 500 Abarth and 500X — genuinely entertaining to drive, but built around a complex hydraulic valve-timing system that's the clear focus of any used buyer's attention.
MultiAir is a genuinely clever system — it uses hydraulic actuation to control intake valve timing and lift electronically rather than through a conventional camshaft profile, improving both efficiency and responsiveness. That cleverness comes at a cost: the solenoid and hydraulic components are more failure-prone than a conventional valvetrain, and a failing MultiAir solenoid can cause rough running, reduced power, or a check engine light. The timing belt (not chain) also needs its own scheduled attention.
Not a guarantee, but a pattern seen consistently across owner forums and independent-garage reporting.
First reports of MultiAir solenoid-related rough running or reduced power on affected examples.
Timing belt and water pump service — non-negotiable, regardless of how the engine sounds or runs.
Examples without early MultiAir symptoms and with documented belt service commonly continue reliably.
This is the defining check on this engine: ask whether any MultiAir-related warning lights or rough running have ever occurred, and have a specialist run a diagnostic scan before buying if there's any doubt.
Get documented proof of the timing belt replacement interval — this is an interference design, same caution as the simpler FIRE engine.
A rough idle or hesitation on throttle application, particularly when cold, is a meaningful warning sign worth having assessed by someone familiar with this specific system.
Model-specific pages, with notes on how it behaves in that particular car.