sounds like you had air in the cooling system. that would be the cause of the erratic temperature gauge, not a faulty sensor.
for air to be present, it has to be there because of a leak. have the cooling system pressure tested at any garage and tighten/replace any leaking hoses... and hope your head gasket hasn't blown.
good luck.
for air to be present, it has to be there because of a leak. have the cooling system pressure tested at any garage and tighten/replace any leaking hoses... and hope your head gasket hasn't blown.
good luck.