i always thought temp gauges had h and c or numbers.
is it a mexican vehicle with
ada and (m)ucho caliente?
1. air pockets could cause that but generally work their way out of the system. you could have it vacuum filled if you determined that to be the cause.
2. in changing parts, you couldve dislodged some foreign particles which circulated through your cooling system and settled in to restrict coolant flow.
3. its an electrical sending unit. is it possible the wiring developed a short or is touching something which could effect the reading?
is it a mexican vehicle with

1. air pockets could cause that but generally work their way out of the system. you could have it vacuum filled if you determined that to be the cause.
2. in changing parts, you couldve dislodged some foreign particles which circulated through your cooling system and settled in to restrict coolant flow.
3. its an electrical sending unit. is it possible the wiring developed a short or is touching something which could effect the reading?