Thread: Thermostat orientation, V8

Does anyone know the reason for the 'Top' marking on the thermostat, and the direction in the manual to refit this way? What will happen if it's refitted some other way?

I ask (obviously!) because it was only after I finished the job that I noticed this requirement. No idea which way the new one went in. Must I drain the system and refit?

"Top" generally refers to a small bleed hole in the thermostat plate to let air bleed past a closed thermostat. In a D1 so long as the 8mm bypass hose via the throttle heater circuit is flowing well I'd not worry about it.