Engine overheat and boiled over

Hi there I have had this car 9 months it is a c3 desire 2007 model in good condition with 46000 miles on clock as I parked up last week and left the engine running while un the car I heard bubbling and car spat it's coolant out down by the passenger wheel I left it to cool down and topped it up then drive back home where it leaked again I changed the thermostat as I tested it in boiling water and it never opened and refilled the coolant while bleeding it at heating pipes to cab and at the point on the side of the engine until coolant came out but since then I've never seen or heard the fan run on the radiator if this wasn't running would the pressure on the engine blow coolant out the breather tube or is something else wrong thanks

Hi

This is the way to purge the Citroen C3 Cooling system

Arfur Dent wrote: ↑Thu Dec 02, 2021 5:48 pm Hi

This is the way to purge the Citroen C3 Cooling system

Thanks for the link but why does it keep throwing it out its either a leak or will fan not coming on overheat it to this point

Scobo53 wrote: ↑Fri Dec 03, 2021 11:21 am

Arfur Dent wrote: ↑Thu Dec 02, 2021 5:48 pm Hi

This is the way to purge the Citroen C3 Cooling system

Thanks for the link but why does it keep throwing it out its either a leak or will fan not coming on overheat it to this point

Because you didn't purge the air out?

It's not possible to diagnose the fault properly until the system is at a known state of coolant filling that excludes any air you allowed to enter when the thermostat was off.

OK arfur dent I've found my radiator leaking and have changed I'll follow the filling instructions you supplied tomorrow thanks for the help scott

Do you have air conditioning?

If you pull the green connector off the sensor on the thermostat housing (while the engine is running) the radiator cooling fan should run at full speed. And the over temp light should come on the dash.

Under normal circumstances the radiator fan doesn't run much at all. However this does not seem like a normal situation. If your engine is boiling over and the fan is not coming on, that's not normal. Unfortunately the facelift models do not have a temperature gauge just a warning light and that's not very helpful. Did the light come on when the engine boiled over? There should have been three beeps and the over temp light on. Did it "boil over" or just burst the radiator?

Sorry about all the questions but you might have multiple problems.

OK thanks for letting me know I have bled the engine and heater pipes but doesn't feel like there is water in the radiator hoses and now the engine coolant light Is on and 3 beeps and stop engine overheating when I start the car the radiator fan runs all the time and doesn't stop

Scobo53 wrote: ↑Sat Dec 04, 2021 12:10 pm OK thanks for letting me know I have bled the engine and heater pipes but doesn't feel like there is water in the radiator hoses and now the engine coolant light Is on and 3 beeps and stop engine overheating when I start the car the radiator fan runs all the time and doesn't stop

Did you refill the system as described in Arfurs link?

Arfur Dent wrote: ↑Thu Dec 02, 2021 5:48 pm Hi

This is the way to purge the Citroen C3 Cooling system

Yes I followed it but don't know it only took 6litres and was full to top and S soon as I started the engine the fan runs straight away it's now saying its got a coolant sensor and engine overheat could it be the coolant sensor blue one and what is in the part where the thermostat is attached
To on side of the engine as I can't feel water in the hoses can this part stop water or just the spring thermostat thanks

If you get the over temp warning straight away but the engine is cold, there is obviously a fault in the sensor circuit.

Yes, if the 'blue' sensor is open circuit, that will cause the system to fail too. It monitors the actual cylinder head temperature (NOT the coolant temperature) and goes open circuit when the cylinder head temperature reaches 120'C. It is normally an electrical short circuit to the cylinder head.

Have you replaced the 'green' sensor at all? That is the usual suspect in this situation.