Overheating Problem – Ford Fiesta HXJB I4 16v 2012

Car Forum Repair & Maintenance Overheating Problem – Ford Fiesta HXJB I4 16v 2012

  • StaceyAEH
    Community Member
    August 20, 2022 at 6:52 pm

    Ford Fiesta CL WT 2012

    Hi all,

    I have had issues with over heating for the last few months. The overheating tends to happen more idling at lights and parked. Driving the temps range from 85-100C (185-2015F).

    I’ve had mechanics say they cant find a problem or that its not over heating when they have it.

    What I know:
    The previous owner put copper stop leak in the system, leaking was from a cracked overflow (Replaced) (I know this is a red flag but I didn’t become aware of this until months later)
    The radiator has been replaced, it had 3/4 blocked flow. (the mechanic who did this did not perform a coolant flush)
    The thermostat has been replaced.
    Temperature sensor has been replaced..
    I have Performed a full flush of the coolant system with Nulon Extreme Cooling System Flush.
    The water pump seems to be working as my heater core works very well.

    My Fan turns on at 90C (195F).
    The thermostat opens at 90-95C (195-205F) but the temperature only drops a few degrees and then continues to rise.
    I have no white smoke coming from the exhaust.
    I have no visible leaking, But I have to fill my Coolant from min to the max line once a month.

    Does anyone have any clues as what the reason for my overheating could be from.?

    Brand: Ford
    Model: Fiesta
    Year: 2012
    Engine: HXJB I4 16v

    Community Member
    August 22, 2022 at 12:43 pm

    Hi StaceyAEH.

    that seems like a bit of an issue. Now, what’s your temperature like when you’re driving at speed (i.e. on the highway)?

    Aslo, when it starts to go up while idling, can you rev it up to say 2000 RPM and see what happens?

    Let me know.

    Community Member
    August 22, 2022 at 12:57 pm

    Highway temps between 90-100C.

    Idling at 2000 the temp just goes up quicker.

    Community Member
    August 29, 2022 at 7:03 am

    Have you vented the cooling system after doing all the repairs? You may have air inside it, which can cause such issues.

    Additionally, your coolant pump might be worn out and unable to shift enough coolant, which results in the engine running hotter than it should.

    Community Member
    September 16, 2022 at 1:23 am

    I’m told these engines are not common for head gasket issues but the plastic thermostat housing which is located behind the Aircon pump commonly fractures and leaks .

    They can also be difficult to bleed of air correctly. and the fans are designed to autodestruct when the brushes wear out (though yours is apparently OK)

    An airlock shouldn’t lead to consistent coolant loss though if its in the process of clearing itself escaping air may cause blow-off from the coolant reservoir. An air lock can thus do a fairly good impersonation of more serious head gasket failure.

    I had these symptoms on the Skywing which everybody and his dog assured me was a head gasket failure; which are apparently quite common on these 3-cylinder engines, especially when turbo-boosted.

    Cleared itself eventually

    These days if I drain the system I clear airlocks by boiling the coolant with the radiator cap off and the fan disabled. I have a large plastic funnel which fits into a smaller plastic funnel which fits in to the radiator fill port, and gives the coolant somewhere to expand.

    Its a bit alarming but I think its better than risking local overheating by using the engine normally with an airlock.