I have a 2010 Citroen C3 Picasso 1.4 petrol. A few months ago my car fan became very noisy after a long journey. Since then the car control panel is telling me the engine is overheating even if I have only just started it and the fan is going mad.

I took it to my mechanic who couldn't do anything because the message wouldn't show when I was at the garage. They sent me to an electrical mechanic who looked over the car and said the temperature sensor was showing at 240 degrees. I booked it in with my garage to replace. Unfortunately when I took it to the garage the message had disappeared and they said to leave it until it appears again.

My view is it is an electrical fault. What are your thoughts? Also every other day it struggles to start. It will start after a few pumps of the accelerator. On a long trip over the weekend I did a little test. If I am driving along at a steady pace and then (for example accelerate to over take) the warning light will appear telling me the engine is overheating. I had a look under the bonnet at our rest stop and the engine was as it should be, nothing to suggest overheating.

  • 1
    Welcome to StackExchange! If indeed the vehicle is not overheating, It sounds like it's most likely a coolant temperature sensor which is failing. They should be able to take readings from it and see if they are falling within range for the sensor. You will want to make sure that you can feel heat at both the top and bottom radiator hoses, to ensure coolant is indeed circulating.
    – NitrusInc
    Commented Apr 10, 2018 at 20:04
  • 2
    Make, Model, and year of vehicle?
    – Moab
    Commented Apr 10, 2018 at 20:19

1 Answer 1


There are a few common faults with this vehicle.

The temperature sensor is the most easy and least expensive to change which is on the thermostat housing on the end of the cylinder head above the gearbox.

If fitted with the electrical thermostat this can stick causing the coolant not to reach the radiator but as you said you get the warning as soon as you start the car it probably isn't this.

The ECU is a very common fault which requires sending the ECU away to be tested and repaired. This will cause the exact faults you are experiencing but it is usually a permanent fault.

I would have the mechanic load test the wiring and replace the sensor. If the fault comes back then send the ECU to a specialist for testing.

  • If you found this useful please up vote and vote as best answer Commented Apr 11, 2018 at 19:09
  • BTW, the temperature sensor probably costs between $10 and $20, and only takes a few minutes to replace. In other words, it is a relatively "cheap" fix that you should do first, as Terry said.
    – sam
    Commented Jul 10, 2018 at 22:32

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