Peugeot EC5

PSA's 1.6-litre naturally aspirated petrol four for markets outside Europe — in the Peugeot 208 and Partner and the Citroën Berlingo and C-Elysée.

It is the engine you meet when a European model was built somewhere else. The same car sold in France on a PureTech three-cylinder is sold in South America and China on this, and the two have nothing in common: a diagnosis written for one is wrong for the other, which is the whole reason to establish the code before anything else.

What that means in practice is good news. It is port-injected, belt-driven and naturally aspirated — so it has none of the PureTech's wet-belt failure, none of the intake carbon that direct injection brings, and no turbocharger. An engine with fewer ways to fail is genuinely simpler to diagnose, and its complaints are the old-fashioned set: vacuum leaks, a tired idle control, coil and plug wear, and a coolant temperature sensor that skews fuelling without setting a code anybody notices.

It shares its architecture with the long-running TU family, which is worth knowing when a search on the code returns nothing: TU5 results often apply. Where they do not is emissions equipment and engine management, which are specific to the market the car was built for.

English-language documentation is thin, and that is the practical constraint. Parts and procedures are easiest to find under the local market's own model name rather than the European one.