Peugeot BlueHDi (badge, not an engine)

BlueHDi is a badge, not an engine. It is PSA's name for a diesel meeting the emissions standard of its day with SCR and AdBlue, and this catalogue's rows show it across 1.5, 1.6, 2.0 and 2.2 litres in Peugeot, Citroën, DS and Opel.

Every family it covers already has a page here — the DV5, DV6, DW10 and DW12 — which is exactly why the badge is worth a page of its own: it is the thing printed on the car, and it resolves to four different engines.

Establish the family code — it is on the engine and in the service record — and go to that page. What follows is what the badge itself genuinely tells you.

⚑ BlueHDi means AdBlue, and AdBlue is a system with its own failures that have nothing to do with the engine. A car in limp mode with a countdown to no-start is very often the NOx sensor or the AdBlue injector, not the diesel in front of them. Neither is an engine fault and neither is diagnosed by looking at the engine.

The AdBlue tank heater and level sensor fail in cold climates and produce the same countdown, and the fluid itself has a shelf life — a car that has stood with old AdBlue in it can crystallise the injector.

The DPF behaviour is ordinary and short journeys ruin it, as everywhere; what is not ordinary is that on these cars a DPF additive (Eolys) is consumed and must be topped up, and its absence is a separate fault from the filter itself.