1600 and 1800 cc. engines do not have the same type of radiator as the 12,13 ones.
Much more easier to clean and no clogging issues.
Unfortunately The use of the silica/sand based compounds, used only in UK, roads during winder time , even after so many letters adressed to the UK ministry of transportation had no results.
Similar issues are faced with some vehicles from Stelandis and VW group.