you have a 7 lb rad cap, that's not a thermostat, they're rated for temperature - if the gauge shows 140 when it's well warmed up then you have a bad gauge [stock?] or NO thermostat - you need to open the housing and check for a thermostat and replace it with a 180 degree new one, especially for winter, which will mean when warmed up the engine will hold 180 or above .... and like George says. make sure it's warmed up before driving, 140 is not warm
Bill
