After the major facelift of 1987, and the introduction of the DOHC engines in 1989, further changes to the Sierra were superficial.
Some detail styling changes were made in 1990, when the dashboard styling was freshened up, the front was given clear-lensed indicators, the rear given smoked rear lamp lenses, the steering wheel redesigned and a new front grille was added, together with fuel injection as standard, 15-inch wheels and rear disc brakes.
 UK production of the Sierra ceased in 1990 with right hand drive production moving to Belgium.

For the 1991 model year,  the 1.6 litre Pinto engine was finally dropped and replaced by a CVH unit of similar capacity, marking the end of the venerable Pinto unit after it had been introduced in the Cortina/Taunus some 21 years earlier.
 The 1992 model year cars saw the final revisions  - most notably the dashboard which gained a more rounded instrument binnacle similar in style to the 1990 Escort and Orion, along with specification, colour and trim upgrades across the whole range.

By 1989, Ford had confirmed that the successor to the Sierra (due by 1993) would feature front-wheel drive, and a number of concept cars were shown in the motoring press, hinting at what the new car might look like.
By the early 1990s it had become clear that the Sierra had fallen out of step technologically against modern Japanese rivals which offered multi-valve engines and multi-link rear suspension.
All of these features appeared on the Sierra's replacement, the front-wheel-drive Mondeo, which was unveiled in November 1992 and went on sale the following March.
After the major facelift of 1987, and the introduction of the DOHC engines in 1989, further changes to the Sierra were superficial. Some detail styling changes were made in 1990, when the dashboard styling was freshened up, the front was given clear-lensed indicators, the rear given smoked rear lamp lenses, the steering wheel redesigned and a new front grille was added, together with fuel injection as standard, 15-inch wheels and rear disc brakes.  UK production of the Sierra ceased in 1990 with right hand drive production moving to Belgium.
For the 1991 model year,  the 1.6 litre Pinto engine was finally dropped and replaced by a CVH unit of similar capacity, marking the end of the venerable Pinto unit after it had been introduced in the Cortina/Taunus some 21 years earlier.  The 1992 model year cars saw the final revisions  - most notably the dashboard which gained a more rounded instrument binnacle similar in style to the 1990 Escort and Orion, along with specification, colour and trim upgrades across the whole range. 
By 1989, Ford had confirmed that the successor to the Sierra (due by 1993) would feature front-wheel drive, and a number of concept cars were shown in the motoring press, hinting at what the new car might look like. By the early 1990s it had become clear that the Sierra had fallen out of step technologically against modern Japanese rivals which offered multi-valve engines and multi-link rear suspension. All of these features appeared on the Sierra's replacement, the front-wheel-drive Mondeo, which was unveiled in November 1992 and went on sale the following March.
Ford Sierra