The protest began after the 210 staff at the plant were told yesterday it was to shut down immediately.
The workers say they intend to continue the sit-in until their redundancy deal is finalised.
The plant makes engine parts for the Ford Fiesta car and was previously owned by the Ford Motor Company.
Its future had been in doubt given the economic downturn and the worldwide drop in car sales.
Workers are also staging protests at factories in Basildon in Essex and Enfield in north London.
Visteon employs 173 staff at the Basildon plant and 227 in Enfield.
The wider group has a 33,500-strong workforce and operations in 27 countries.
