1.4 HDI Coolant temperature gauge red light flashing

Hi all. I just bought a 2004 C3 1.4 HDI. Last night and this morning when started, the top red light on the coolant temperature on the dash started to flash with a beeping sound. it went after 30 seconds and did it again after like 1 minute. Then, it was gone. The temperature went us as normal(3 bars) after that. I checked the coolant level, which is ok. Does anyone know what is that about? Any help much appreciated. Thanks all.

Obedjugoo wrote:Hi all. I just bought a 2004 C3 1.4 HDI. Last night and this morning when started, the top red light on the coolant temperature on the dash started to flash with a beeping sound. it went after 30 seconds and did it again after like 1 minute. Then, it was gone. The temperature went us as normal(3 bars) after that. I checked the coolant level, which is ok. Does anyone know what is that about? Any help much appreciated. Thanks all.

Its the coolant level sensor. You checked the level and its between mini and maxi? Then the sensor could be faulty.
There is a post where the sensor was coated with oil and this stopped it working. The coolant had oil in it

Thanks. I have to rectify. It's ths coolant LEVEL sensor not temperature sensor as I wrote before.
The coolant level was just above the min mark so I topped it up but the warning still came up. So I removed the sensor and gave it a good clean. It had a lot of limescale on it. So far no warning yet. Will see in a few days.

Obedjugoo wrote: I removed the sensor and gave it a good clean. It had a lot of limescale on it. So far no warning yet. Will see in a few days.

Good. Scale does indicate that incorrect coolant was used and if there is scale on the level sensor, expect scale on the water pump and in the radiator amongst other places

I see... I guess I will have to do a flush. Thanks for the info

Obedjugoo wrote:I see... I guess I will have to do a flush. Thanks for the info

This would be a good idea

Looking at the coolant drained out can also give you an indication of the state of servicing and 'health' of the cooling system.

A flush should include something other than clean water that will dissolve any internal scale/mineral build-up, like this WinPlus BAF100 (on Amazon)

Tips on refilling the C3 cooling system topic may also be useful to you

Thanks for the tips. Regarding the sensor, after cleaning and refitting it, I still have the red light flashing but it doesn't do it everytime I start the car. So I am guessing I need to replace the sensor.