Fiat Turbo

Fixed-geometry turbos on Fiat petrol engines, variable-geometry turbos on Fiat diesel engines: two very different approaches

The Fiat range spans two distinct worlds. On the diesel side, the JTD, Multijet and TD units fitted to the Ducato, Doblo, Bravo, Scudo and Croma almost all run a variable-geometry turbo: the adjustable vanes allow boost pressure to be modulated according to engine speed, but they accumulate soot deposits and seize up — particularly on the 1.9 JTD (codes 182B9000, 223A7.000, 223B1.000) and the 2.3 Multijet (F1AE0481N, F1AE3481D, F1CE0481D). The larger diesels in the Ducato — 2.8 TD/TDI (8140.43) and 3.0 Multijet (F1AGL411) — are subject to severe thermal stress caused by prolonged load cycles in commercial use. At the other end of the spectrum, the petrol turbos on the 1.4 T-Jet (codes 198 A1.000, 199B1.000, 199B6.000, 199B7.000), which power the Punto, Grande Punto, Bravo and 500X, use a fixed-geometry turbo with a wastegate: a simpler design, but one that heats up very rapidly, putting the bearings and seals under strain as soon as the lubrication circuit deteriorates.

The 0.9 TwinAir and the 1.3 Multijet: two tricky identification cases

The 0.9 TwinAir (codes 312 A2.000 to 312 A7.000) is a classic example of the pitfall: six power outputs (60, 65, 78, 80, 86 and 105 hp depending on the variant and market) from the same two-cylinder block, with distinct turbo references according to the engine map. The engine code stamped on the block is therefore essential to avoid any error. The 1.3 Multijet 95 hp (199 B6.000 / 199 B7.000), found on the Panda, Punto and 500L, shares references with PSA units (codes 9HU, DV6UTED4) on the Scudo and Fiorino: the manufacturer's reference on the CHRA cartridge is the only reliable means of identification, as the external dimensions can be identical between references that are not interchangeable.

Symptoms and root causes to address before any replacement

On variable-geometry diesels, the most common symptoms are gradual power loss, whistling under acceleration, and the engine entering limp mode due to detected over- or under-boost. On petrol T-Jet engines, blue smoke on start-up and abnormal oil consumption are generally signs of failed valve stem seals or bearings. In both cases, replacing the turbo without addressing the root cause — EGR or DPF fouling, degraded oil, an air leak on the intake circuit — will lead to premature failure of the new or reconditioned unit. The range covers fifteen Fiat models, from the Uno to the Fullback, with turbos available new or reconditioned on an exchange basis depending on the reference.