Opel 20NE / X20XEV / C20LET

Opel's 2.0 to 2.4 four — Family II — in the Vectra, Astra, Omega and Calibra, and across Vauxhall and Holden.

⚑ Read the code as a sentence and it stops being random. The first letter is the emissions generation — C, X, Y, Z, then A and B — the digits are the displacement, and the last letters say what it has. X20XEV is a Euro-2 2.0 with a catalyst and sixteen valves; C20LET is a Euro-1 2.0 turbo. Once that is clear the whole Opel range becomes legible.

It is belt-driven and it is an interference design, which on cars of this age with unknown history is the decision that matters.

Its recurring items are the era's: a distributor or DIS module that fails with heat, an idle control valve that carbons up and gives a hunting idle, and a crankshaft sensor whose failure presents as an intermittent no-start.

The C20LET and C20XE are the performance members and are heavily modified; a stamped code on a rebuilt one may no longer describe what is inside it. The Ecotec L850 that replaced the family is a different engine with its own page here.