Opel X20DTH / Y20DTH

Opel's 2.0 DTI — the X20DTH and Y20DTH — in the Vectra, Astra, Omega and Zafira.

It is a direct-injection diesel with a rotary pump and no common rail, which places it between the eras: there is engine management to read, and it is thin. It is not the later 2.0 CDTi, which is a common-rail engine with its own page here — the badge changed with the technology, and DTI is the tell.

Its known items are the injection pump's electronics and the EGR. The pump-mounted controller fails with heat and gives an intermittent cut that clears when cool, and the EGR carbons shut and produces smoke and a lack of power without necessarily setting a code.

The timing belt drives the injection pump as well as the camshaft, so a belt service is not the job it is on a petrol engine and getting the pump timing back is the part that takes the skill.

Its origins are in an Isuzu design, which is worth knowing when Opel material runs out.