Hyundai S6DA (3.0 V6 CRDi)

Hyundai's 3.0 V6 common-rail diesel — the S-engine — in the Veracruz and the Kia Mohave.

It is Hyundai's only V6 diesel and it is rare, which is the practical constraint: specialist experience is thin even inside the dealer network, and almost nothing written about the four-cylinder R-family CRDi engines applies.

Its known items are the ones a V6 diesel usually has, made worse by access. The turbochargers and the EGR sit in the V, so a job that sounds routine means removing the intake system — worth saying before a quote is given.

The emissions equipment is where most complaints originate, and the duty cycle that breaks it is a heavy vehicle on short journeys. A rising oil level is fuel dilution from failed regenerations, not a servicing error.