High temperature but fan turns on (d14)

Discussion in 'Honda D-Series' started by DhoTjai, Friday 27th Jul, 2018.

  1. DhoTjai Club Member ★ ☆ ☆ ☆ ☆

    Netherlands DhoTjai Rotterdam
    My Civic is getting high temperature (max) but the fan does turn on.

    1. Fan turns on
    2. All hoses are warm/hot
    3. I do not see any leaks
    4. It has enough coolant
    5. I saw some dirty stuff on the radiator cap and cleaned it
    6. I opened the radiator cap, topped up some coolant, started the car with heater on max and waited till the fan turns on
    7. Temperature drops when heater is on, but will slowly get to max

    Are the hoses bad?
    Radiator bad?
    Fan bad?
    Need a flush?
    Bad sensor?
    Bad thermostat?

    Does the radiator fan always need to be running when airco is on?

    (I replaced the thermostat two years ago, because the fan did not turn on and lower coolant hose was cold after 30 minutes driving.)
  2. DhoTjai Club Member ★ ☆ ☆ ☆ ☆

    Netherlands DhoTjai Rotterdam
    Problem is fixed, it was clogged up with crap (at the thermostat).
    I cleaned all hoses, cleaned the old thermostat and flushed the coolant system twice. Then I replaced the old thermostat with a new one and refilled with new coolant.
    Hondalad likes this.
  3. Hondalad Senior Member ★ ★ ☆ ☆ ☆

    England Steve Derbyshire
    I'm glad you found the problem, I would have bet on a thermostat too. Even if they're stuck shut they normally have a bypass to allow a small amount of coolant through so it doesn't dead end so it can look like everything is working perfectly like you said with the hoses being hot.
  4. DhoTjai Club Member ★ ☆ ☆ ☆ ☆

    Netherlands DhoTjai Rotterdam
    Yeah, I did not know that. I thought a broken thermostat would lead to a cold hose (lower one), but it can cause more problems =(

    It was a hell driving in this hot weather (34 C) with heater fully on, I do not want to experience that again!