Cadillac High Technology engine

The Cadillac High Technology engine was a V8 built by the Cadillac division of General Motors from 1982 to 1995. It arrived as the replacement for the troubled V8-6-4 cylinder deactivation engine and was rushed into production for 1982 as the HT4100, a 4.1 litre aluminium block engine with cast iron heads, throttle body injection and an on-board computer that could display engine parameters on the climate control panel. It proved failure prone, with intake manifold gasket, oil pump and block thread problems, and Cadillac enlarged it into the 4.5 litre and 4.9 litre versions that followed in 1988 and 1991. A reinforced multiport version powered the Allante. For about 25 years it was the last engine family used only by Cadillac, until the Northstar replaced it.