Ford S-Max Turbo

Ford S-Max Turbo: from the 1.8 TDCi to the EcoBoost – the failures that lead to replacement

On the S-Max, turbo failure almost always follows the same pattern: insufficient lubrication or oil left in service too long clogs the bearings, and the turbine shaft begins to develop play. The symptoms are characteristic — a sharp whistling noise on acceleration, blue-grey smoke from the exhaust, and a noticeable loss of power, sometimes accompanied by the vehicle entering limp mode on variable-geometry versions. On the 1.8 TDCi in particular, progressive fouling of the variable-geometry actuator is a well-documented weak point: the rod or vanes seize up, and the turbo can no longer regulate boost pressure correctly. Fitting a new unit without having addressed the root cause — oil circuit condition, EGR fouling, blocked DPF — will inevitably lead to another failure.

Five engine variants, very different turbos

The S-Max covers a wide range: two families of 1.8 TDCi (engine codes QYBA, QYWA for the first, FFWA, QYWA for the second), a 2.0 TDCi 163 hp (engine code TXWA), the 2.5 ST petrol (engine codes B 5254 T3, B 5254 T7, HUWA, HYDA) and the 2.0 EcoBoost 240 hp (engine codes R9CD, R9CI). The engine code stamped on the block is the only reliable way to identify the exact reference: the same 1.8 TDCi can belong to one of two turbo families with distinct references depending on its engine code. The 2.0 TDCi 163 hp and the 2.0 EcoBoost 240 hp share no common parts despite having the same engine capacity. On the 2.5 ST, four engine codes coexist, each corresponding to a different reference. All turbos listed on this page are new parts, sold with no old unit to return, and conforming to original manufacturer references.

What to check before fitting

Whatever the engine variant, a new turbo will solve nothing if the root cause has not been eliminated. On the S-Max diesels, this means checking the condition of the oil supply circuit (oil strainer, turbo oil feed pipe), ensuring there are no foreign bodies in the intake circuit, and confirming the DPF is not overloaded. On the 2.5 ST and 2.0 EcoBoost, failures are more commonly linked to degraded oil or an oil change interval that has been left too long. In every case, priming the lubrication at start-up after replacement is critical to the longevity of the new unit.