Volvo D5252T

The 2.5 turbodiesel in the Volvo 850, S70 and V70.

⚑ It is a VM Motori engine, not a Volvo one, and the catalogue's own rows say so. That matters because the later D5244T five-cylinder — the engine most people mean by a Volvo diesel — is Volvo's own and shares nothing with it. Two five-cylinder diesels, two companies, one marque.

It is an indirect-injection engine with a mechanical pump: no common rail, no particulate filter, nothing to regenerate. Almost every modern diesel complaint is inapplicable.

Its known weakness is the cylinder head, and specifically that VM used individual heads per cylinder — an unusual design that makes a head gasket failure a different and more involved job than on any other engine in this catalogue. Coolant loss with no external leak is the tell, and the repair is not the routine one.

Parts and specialist knowledge are both very thin now, which is usually what decides whether one of these cars is worth keeping.