Ford Figo coolant diagnosis

[Jacques93]

30-03-2020

Hey all.

I'm new to the forums, I've joined out of desperation.

I'm driving a Ford Figo 2010 1.4 petrol ambiente(Duratec)

I've been having problems with this car's heat since 2017.
I'll spare you the long story.

On 24-03-2020, my car started but had a rough idle, revved it up a little and it was back to normal, drove 2km, switched it off and went to the ATM and back, started again with a rough idle, same story. About 2km later i noticed white smoke, not long after the fan came on high speed and the temp light came on, I stopped immediately, popped open the hood and heard a hissing noise. Water bottle cracked. pushed the car home, replaced the water bottle and tried it again, still rough idle and a heavy white smoke from the exhaust. Mayo under the oil cap.

Went and got dirty over the weekend replaced the following :
Head gasket, valve stem seals, water pump, water bottle, thermostat, intake manifold gasket, exhaust manifold gasket, oil filter, air filter, fuel filter, oil and engine coolant.
I re-seated the valves and checked for leaks - none.
Flushed the radiator and checked for good flow.

My problem is: The white smoke is gone, but the temp light and high speed fan persists.

Test mode shows 28C in the morning before start. Temp gradually increases to 106C low speed fan comes on and temp goes down to 99C -repeat.
While driving in test mode, temp increases to 111C and Hish speed fan with temp light comes on.

Upon diagnosis:
Expansion bottle is hot, Hose from cylinder head to radiator is hot, hose from radiator to Cylinder block(thermostat is luke warm. Radiator is warm.
General engine area & hood feels cold.
Revving the engine up when stationary significantly cools it down, but it steadily rises while driving(No traffic due to lockdown)

Test mode DTC codes : C100, C121, C151.
I dont know how to read the codes.

My father in law says it could be the ECT sensor that is no longer functioning as it should and is giving lower values than it should.

I need help!🙏