Fiat 500 1.3 Multijet Mk1

The 1.3 Multijet needs regular motorway running (20+ km at 70+ km/h) to regenerate the DPF. A city-used 500 rarely meets these conditions, so soot accumulates until the DPF triggers forced regenerations more and more frequently. Early warning signs are the DPF light appearing, increased fuel consumption, and fast-rising engine oil level on the dipstick. A forced regeneration at a Fiat dealer or specialist costs €100-250, cleaning/burn-off (off-car) runs €300-500, and a new OEM DPF is €1,000-1,500 fitted. Aftermarket DPFs exist from €400-700 but quality varies. Removing or disabling the DPF is illegal in EU/EEA markets and will fail emissions testing.

This is the single most serious risk on any short-trip Fiat 500 1.3 Multijet. During a DPF regeneration, extra diesel is injected post-combustion to burn off soot. If the regeneration is cut short — typically by stopping the engine before it completes — the unburned fuel drains past the piston rings into the sump, raising the oil level. If the dipstick level rises more than about 10-15 mm above MAX, the engine can draw oil vapour through the turbo/intake and run on its own sump oil, over-revving uncontrollably and destroying itself in seconds. Multiple owner reports describe exactly this outcome. Check the oil level and smell it for diesel on every inspection. If oil is above MAX, change it immediately and investigate the DPF system. A catastrophic runaway event is effectively an engine-out repair: €3,000-5,000 for a used engine fitted, more for a rebuild. Less severe oil dilution is solved with early oil changes (€80-150).

The Multijet II EGR valve circulates exhaust gas into the intake, where it mixes with oil vapour and forms thick carbon deposits in the manifold and ports. Typical symptoms are the engine warning light, loss of power and limp mode, and rough idle. A full clean of EGR valve and manifold at a specialist is €150-250; replacement of the EGR valve (commonly around €200-300 for the part) plus labour totals around €350-500. If the intake manifold itself is replaced rather than cleaned, costs rise to €700-900. Owners who drive mostly motorway miles and use correct low-SAPS engine oil see this problem much less. Chemical intake cleaning every 40,000-60,000 km helps.

The small KKK/IHI VGT turbo on the 1.3 Multijet is reasonably durable but sensitive to oil quality, short-trip use, and DPF-related oil dilution. Symptoms are whistling or whining on boost, blue smoke on acceleration, loss of power, and oil misting in the intercooler pipework. On high-mileage or badly-serviced cars the vanes can stick from carbon build-up, triggering a limp-mode warning. A reconditioned turbo is €400-700 plus roughly €300-500 labour; OEM new units are €900-1,200 fitted. Check for turbo issues by listening for unusual whistle on acceleration and inspecting the intercooler hose for oil residue.

Like most modern small diesels, the 1.3 Multijet uses a dual-mass flywheel to damp out engine vibration. The DMF wears faster than on petrol cars because of higher torque and the low-rev driving style typical of urban diesel use. Symptoms are a rattle at idle, gear-change judder, and a shudder when pulling away. Replacing the DMF alone is uneconomical — it is always done together with clutch and release bearing. A complete DMF/clutch job at an independent specialist runs €900-1,300; at a Fiat dealer expect €1,400-1,600. Typical failure mileage is 120,000-180,000 km but can be earlier on driving-school or ex-rental cars.

The 1.3 Multijet uses Bosch or (later) Delphi injectors that can develop internal leaks after 120,000-180,000 km, especially on cars run on cheap fuel without additives. Symptoms are difficult cold starting, rough running at idle, white smoke, and a rising idle smell of diesel. A basic leak-off test costs €30-60 and identifies the faulty injector. Remanufactured injectors are €120-180 each; a full set of four plus coding runs €700-1,200. If only one injector has failed, replacement is €250-400. Use branded diesel and add a cleaning additive every 10,000 km to prolong injector life.

This is the same column failure that affects every Fiat 500 Mk1 regardless of engine. A torque sensor inside the EPS column wears out and triggers fault code C1002, causing intermittent or total loss of assistance. A new Fiat column is over €800 plus coding; specialist rebuild services across Europe offer repairs for €300-500 with a lifetime warranty and no coding needed. Most common after 80,000-120,000 km.

Shared with all Fiat 500 Mk1 models. The cast-iron oil sump has poor factory corrosion protection and can rust through within 4-6 years in salt-belt regions (aftermarket replacement €40-80 plus one hour labour). The rear torsion beam spring pans collect moisture and can crack or snap, which is an MOT/TÜV failure; welded repairs are €100-200, complete rear axle replacement €600-800. A diesel 500 is often bought for higher annual mileage, meaning more exposure to winter salt than a city-used 1.2.