Coolant Fan Kicks in at different temperatures

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My Name: scoksen

Member
Posts: 3
Joined: Wed Dec 15, 2021 7:57 pm
Model: C3 2006-2009, Facelift model
Year: 2006 (06)
Engine Size: 1.4
Fuel Type: Petrol
Mileage: 96000
Trim Level: Other
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: LHD (Europe)
Engine name: TU3 (75 PS)

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Hi everyone,

I bought a Citroen C3 almost 1.5 year ago and since then I have a coolant fan problem. Even though I browsed all relevant posts and documents I could access, none of them solved my problem.

The issue is my coolant fan does not kicks in at low speed at 97 degrees as it should. Sometimes it kicks in at 99 degrees at high speed, sometimes does not kick in at all until engine water temp reaches 112-113 degrees and at these point sometimes it kicks in at low speed and stops at 109-110 degrees. I could not specify any patterns how and when it kicks in and little bit confused. My car is a Citroen C3 1.4 petrol X Furio and year is 2006.

Until today,
-green temperature sensor is changed,
-fan relay is changed,
-thermostat (it was broke and stayed open all the time) is changed,
-radiator cap is changed
-during the thermostat change all coolant is changed and checked for air in the coolant circut,
-water pump has been checked,
-coolant fan actuator test has been performed a year ago and no problem has been found

Before the fan relay change I went to local Citroen dealer for check-up and they told me fan relay and radiator cap must be changed but even after the replacements issue continues.

I wonder if are there any other possible reasons cause the fan act like this?

Thanks in advance and best wishes,

SC,
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My Name: C3CAR

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Model: C3 2002-2005, Original shape model
Year: 2002 (02)
Engine Size: 1.4 (16v)
Fuel Type: Diesel
Mileage: 140000
Trim Level: Exclusive
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: RHD (UK)
Engine name: DV4 16-valve diesel (90 PS)
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Hi

How did you measure the coolant temperature and at what point in the cooling system did you measure the temperature?

Is there actually a problem with the car, like the way it runs or you just don't like the temperature the fans work at?
My Name: scoksen

Member
Posts: 3
Joined: Wed Dec 15, 2021 7:57 pm
Model: C3 2006-2009, Facelift model
Year: 2006 (06)
Engine Size: 1.4
Fuel Type: Petrol
Mileage: 96000
Trim Level: Other
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: LHD (Europe)
Engine name: TU3 (75 PS)

Post

C3CAR wrote: Wed Dec 15, 2021 8:44 pm Hi

How did you measure the coolant temperature and at what point in the cooling system did you measure the temperature?

Is there actually a problem with the car, like the way it runs or you just don't like the temperature the fans work at?
I use a ODB2 bluettoth device to watch engine coolant temperature.

In general there is no problem with the car but I am not comportable with the fan and do not want to push temperature so much. I should also mention that sometimes fan does not kick in at all (even at 112-113 degrees) and I turn on the AC or heather to cool the engine.
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My Name: Ozvtr

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Posts: 956
Joined: Wed Jul 10, 2019 3:31 am
Model: C3 2002-2005, Original shape model
Year: 2003 (53)
Engine Size: 1.4 (8v)
Fuel Type: Petrol
Mileage: 80000
Trim Level: Other
Gearbox: Automatic PRND
DPF: No
LHD or RHD: RHD
Engine name: TU3 (75 PS)
Location: Brisbane, Australia.
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Hi welcome,

How much of this work have you actually done?

Is it possible to post a picture of the back of the radiator fan motor?

Does it look like this fan motor?

Citroen C3 engine fan
Citroen C3 engine fan


I don't understand how the engine ECU can detect an engine over temp condition (as reported by the OBD2 reader) and not bring on the fan BUT it will run the fan when you turn the air conditioning on? There is only 1 control line from the engine ECU to the "fan motor" and so the engine ECU has control of the fan...or it doesn't.

Are you getting any trouble codes on the OBD2 reader?
My Name: scoksen

Member
Posts: 3
Joined: Wed Dec 15, 2021 7:57 pm
Model: C3 2006-2009, Facelift model
Year: 2006 (06)
Engine Size: 1.4
Fuel Type: Petrol
Mileage: 96000
Trim Level: Other
Gearbox: Manual 5 speed
DPF: No
LHD or RHD: LHD (Europe)
Engine name: TU3 (75 PS)

Post

Ozvtr wrote: Thu Dec 16, 2021 7:39 pm Hi welcome,

How much of this work have you actually done?

Is it possible to post a picture of the back of the radiator fan motor?

Does it look like this fan motor?

I don't understand how the engine ECU can detect an engine over temp condition (as reported by the OBD2 reader) and not bring on the fan BUT it will run the fan when you turn the air conditioning on? There is only 1 control line from the engine ECU to the "fan motor" and so the engine ECU has control of the fan...or it doesn't.

Are you getting any trouble codes on the OBD2 reader?
Hi,

All of the works has been performed at local repair shop.

I do not have the picture now but I will try to get a picture and post tomorrow or at the weekend. It looks like the fan at the topic you mentioned. Mechanic at the shop told me that the fan is original dual speed factory fan.

I guess fan starts when I turn on the AC no matter what engine coolant temperature is.

There are no trouble codes on the OBD. I got the code P0116 "Engine Coolant Temperature Sensor 1 Circuit Range/Performance Problem" once but it is gone after replacing the thermostat.
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My Name: Ozvtr

Moderator
Posts: 956
Joined: Wed Jul 10, 2019 3:31 am
Model: C3 2002-2005, Original shape model
Year: 2003 (53)
Engine Size: 1.4 (8v)
Fuel Type: Petrol
Mileage: 80000
Trim Level: Other
Gearbox: Automatic PRND
DPF: No
LHD or RHD: RHD
Engine name: TU3 (75 PS)
Location: Brisbane, Australia.
Has thanked: 37 times
Been thanked: 256 times

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scoksen wrote: Thu Dec 16, 2021 8:35 pm It looks like the fan at the topic you mentioned. Mechanic at the shop told me that the fan is original dual speed factory fan.

I guess fan starts when I turn on the AC no matter what engine coolant temperature is.
There are a number of different types of radiator fans and I am not familiar with all the different combinations of C3 variants.
That photo shows the electronic variable speed fan unit and they are known to be problematic. However without knowing what fan unit you have I cant tell you what you might try.
As far as I know, any C3 with air conditioning has this type of fan...but I could be wrong.
Yes, the engine ECU runs both the air conditioning compressor and the radiator fan. When a request comes in from the air conditioning ECU, the engine ECU engages the compressor and starts the fan running. The engine ECU monitors the high pressure line of the air conditioning system and varies the fan speed proportional to the pressure in the line.
That engine ECU is a busy little guy!
scoksen wrote: Thu Dec 16, 2021 8:35 pm There are no trouble codes on the OBD. I got the code P0116 "Engine Coolant Temperature Sensor 1 Circuit Range/Performance Problem" once but it is gone after replacing the thermostat.
Do you mean when you changed the green temperature sensor?
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