Engine temp too high ... in winter [PLS HELP!]

Hi there... had a long trip .. 300km .. was doing 130-140km/h for about 3 hours. Then had a break for a 3 hours. Then hit the road back again .. 300km on the way back again. However, half way on the way back the computer said 'engine temp too high' .. and a red light with a thermometer-like thing appeared on my dashboard behind steering wheel. Keep in mind that it is winter here. Outside temp was about 1 degree celsuis. A few times before I received this 'engine temp too high' message, the computer gave me the message 'risk of ice' ... so u see that it was quite cold. So what i did to remedy the situation was to turn off the engine. Once that was done the fan at the radiator kept on going for about 5-6 minutes .. i guess it was just trying to cool things down further. It was on despite the fact engine was off, but that's not abnormal at all. Have seen it on other cars as well and have experienced it on my c3 in summer. So after 10 min break i hit the road again for the remaining 150 km. At the very end of the trip the same message 'engine temp too high' appeared again, accompanied by the red thermometer light on the dashboard.

What to do? what's causing this? Checked the oil in the engine with the dip stick ... seemed ok. Checked if there's antifreeze liquid ... was plenty of it. What's the reason then? Is it a false positive on the part of the computer or could it be that my engine oil and antifreeze need changing?

Hi soewhaty

soewhaty wrote:Keep in mind that it is winter here. Outside temp was about 1 degree celsuis. A few times before I received this 'engine temp too high' message, the computer gave me the message 'risk of ice' ..

The outside air temperature doesn't have a great bearing on the engine internal temperature, so ignore the fact its 1c outside.

soewhaty wrote:So what i did to remedy the situation was to turn off the engine. Once that was done the fan at the radiator kept on going for about 5-6 minutes .. i guess it was just trying to cool things down further.

Yes, its trying to cool down the engine. Putting the heater on full HOT can also draw heat from the engine to assist cooling. It can also help you diagnose the problem. No hot air means a lack of coolant or lack of coolant circulation.

soewhaty wrote: At the very end of the trip the same message 'engine temp too high' appeared again, accompanied by the red thermometer light on the dashboard.

Red light means don't drive. This is to protect the engine from any further possible damage if the cooling system is as fault (which the car computer thinks it is).

soewhaty wrote:What to do? what's causing this?

Its a cooling system fault. Possibly a stuck closed thermostat, possibly a false sensor reading.

The test would be to check the actual temperature of the cooling system to see if its actually too high or if the sensor is over sensitive. You could just change the sensor, change the thermostat, use something to measure the cooling system temperature.

soewhaty wrote: Outside temp was about 1 degree celsuis.

Coming back to this, considering you have these temperatures, you should also test the antifreeze level of protection by using one of these Refractometer tools. But it may be cheaper to change all the coolant anyway if its for only one use.

Use only the correct coolant for the C3, find out about it here

soewhaty wrote:Is it a false positive on the part of the computer or could it be that my engine oil

Its not the engine oil and you can be sure of this if you have the correct regular oil changes for the mileage.

Could be a false positive, use some of these temperature strips attached to the cooling system pipes in various places to record the highest temperature.

The thermostat will start to open at 89c so the temperature should not rise too much above that on an easy run.

The fan starts at 97c

You get the dash warning at 118c

Thanks a lot man!

As to outside temp .. yeah, I thought so too. It doesn't affect the internal temp of engine, but just thought i should mention it. Well ... if it is +50 Celsius then it might affect it actually, but the cold weather doesn't affect it as I know too.

Putting the heater on full HOT can also draw heat from the engine to assist cooling.

never thought about that but sounds cool and logical. However, I thought having the heating on full HOT would actually warm up the engine. It seems was mistaken. Where does the heating come from anyway? Partly form the engine's heat and partly from the radiator or what? If that's the case, they yes... what you're saying makes sense that heat will just be drawn and dissipated from the engine if I use the heating when engine is overheated. And is there any freon involved in the whole heating concept?

Use only the correct coolant for the C3, find out about it here

btw it looks like some images are missing from C3CAR's initial post here citroen-c3-tips/citroen-c3-coolant-t40.html

soewhaty wrote:However, I thought having the heating on full HOT would actually warm up the engine. It seems was mistaken. Where does the heating come from anyway?

For the petrol it only comes from the cooling system, and the cooling system takes heat from the engine. No harm can be done to the cooling system or the engine by using the heater.

soewhaty wrote:what you're saying makes sense that heat will just be drawn and dissipated from the engine if I use the heating when engine is overheated.

Yes, its just an emergency trick, not something to rely on as a bad cooling system can damage the engine.

soewhaty wrote:And is there any freon involved in the whole heating concept?

Freon - the gas used in air conditioning systems? If you have A/C or climate control the gas used is 1,1,1,2-tetrafluoroethane, R-134a, Forane 134a, Genetron 134a, Florasol 134a, Suva 134a or HFC-134a, also known as norflurane (many names for the same stuff which I call R134a) and this is only found in the air condition loop and not the cooling system of the engine.

soewhaty wrote:Thanks a lot man!

No problem

ok, then i gotta ask this next question. As far as I know using the cooling during hot summers does increase fuel consumption [it is at that point that I thought the cooling system works with freon ... similar to fridges or sth, but as you explained, it seems i'm mistaken]. Point is that I think fuel consumptions goes up during summers when you're in your car introducing cold air from the cooling/air conditioning system. Am I right in this guess about fuel consumption?

And how about winters? Does fuel consumption increase in winters when i'm using the heating system? If I understand what you're saying then it gotta be a NO, since heat comes only from the excess/waste heat produced by the engine. Right?

soewhaty wrote:As far as I know using the cooling during hot summers does increase fuel consumption [it is at that point that I thought the cooling system works with freon ... similar to fridges or sth, but as you explained, it seems i'm mistaken].

Do you mean you are using the Air conditioning? If you are, then yes, running the A/C uses more fuel than not using it. But that has to be offset over opening the windows and messing with the drag coefficient or getting too hot while driving and being uncomfortable.

The A/C cooling system doesn't have anything to do with the engine cooling system, really and its not directly related to your fault.

soewhaty wrote:Point is that I think fuel consumptions goes up during summers when you're in your car introducing cold air from the cooling/air conditioning system. Am I right in this guess about fuel consumption?

As I said above, yes the compressor uses more fuel, but that really does have to be offset against the things I mentioned above. I don't see it as part of your fault as the systems are not directly connected.

soewhaty wrote:And how about winters? Does fuel consumption increase in winters when i'm using the heating system?

No as the A/C is off and its compressor is not running.

soewhaty wrote:since heat comes only from the excess/waste heat produced by the engine. Right?

Right for a petrol, not so right for the diesels from cold. For a petrol the excess engine heat is passed through the engine cooling radiator, if you use the heater on hot, some of the heated water is diverted to the heater matrix in addition to the engine cooling radiator to get it taken away from the engine.

The heater system in a petrol uses a waste product from the combustion process to heat the cabin

But these things don't get to the bottom of your 'over heating' fault as all of the heating and cooling features are will within design limits and if you get an error; its due to a fault (with the system or the sensor).


Arfur Dent has a topic on A/C use citroen-c3-tips/should-i-use-my-air-con ... -t299.html

Yes, my last post has nothing to do with my engine problem. That was due to old coolant I think. But the questions I was asking in my last post were just general ones, not related to an over-heated engine.

Do you mean you are using the Air conditioning? If you are, then yes, running the A/C uses more fuel than not using it

well ... not sure what to call it now ... air conditioning or just cooling ... see my attached image. Even if I don't press the A/C button I can still set the temperature to low or (LO as the car indicates it) and this way I get cold air in during summers. I can get that with and without pressing the A/C button. Have never figured out what difference does it make to have the A/C button pressed or not. That's why I was calling it cooling, not air conditioning, but .. guess it makes no difference.

And yes ... the question was without taking into consideration the drag coefficient, open windows and such.... just purely if there is any difference to fuel consumption when using heating/cooling ... that's all. If I get you correct, on a petrol one fuel cons. goes up when cold air is introduced, and fuel cons. does NOT go up when warm air is introduces, since it comes from the engine anyway.

soewhaty wrote:well ... not sure what to call it now ... air conditioning or just cooling ... see my attached image

Your image is of Climate Control or Automatic air conditioning. When you press the button and set the temperature to LOW, you will get a very cold air blast through the vents selected. If you don't, then your A/C (Air conditioning) is broken, probably low on gas.

soewhaty wrote:I can get that with and without pressing the A/C button. Have never figured out what difference does it make to have the A/C button pressed or not. That's why I was calling it cooling, not air conditioning, but .. guess it makes no difference.

You have some sort of fault as in the summer without A/C you get outside temperature air being blown into the cabin. When you press the A/C button, you can select a temperature for the cabin that is well below the outside air temperature.

Warming the cabin is free, cooling the cabin costs.

C3driver52 wrote:well ... not sure what to call it now ... air conditioning or just cooling ... see my attached image

Automatic A/C is what Citroen call it sometimes, but its the same as Climate Control.