Water & Antifreeze
& Radiator & Fan

Removing the Radiator

Angie Robinson has done this on a 1.4 petrol: All you need to do is remove the front panel which is straightforward.  Then remove the fan; undo the 2 screws at top of it, disconnect the wires and the fan lifts out.  This leaves plenty of room to remove the radiator which pushes forward and just lifts out.  Just over an hour to replace the radiator and reconnect the hoses, there are only 3; gently slide the fan back in and connect up.  Finally refit the top cover.

Others suggest that there isn't room to remove the radiator from behind so it may be necessary to  drop the bumper  before continuing as above

Changing the Antifreeze

Take a little time replacing the antifreeze and water in the engine.  Also re-check after a short run.  Don't forget to replace the antifreeze if you have replaced the water pump.

Take off the air filter assembly for access to the two bleed valves.

Refill the water reservoir - I used this device made up from an empty drinks bottle and old reservoir cap as you will need a head of water above the reservoir to fill the heater matrix.

There are two small black plastic bleed caps - on one of the heater pipes near the bulkhead and on the thermostat itself.  Adjust the heater to supply maximum heat to ensure the heater valve is open, but keep the fan very low or the engine will never warm up!

Fill the reservoir, start the engine and remove the bleed caps one at a time.  Close the caps when there are no more air bubbles coming out.  Keep filling the filler until the reservoir is up to the full mark and allow the engine to run up to temperature; recheck the reservoir level and that there are no leaks.  It can take a while to bleed so be patient and check after the first (very short) run.

Anti-Freeze

I lost some of the water/antifreeze when I replaced the thermostat and replaced it by soft water from the tap.  When I checked the (original) antifreeze was green in colour; the top-up I got from the Peugeot dealer was red so I didn't use it.  When I checked I still had about 40% green antifreeze so should be OK for where I live in the UK.

However I found this statement on  this website 

Toyota uses a red antifreeze in many of its products and should not be confused with the orange type long life antifreezes.  It is essentially the green type of antifreeze that contains red dye to give it the red colour.

The Peugeot Stores operative confirmed this was correct and to top up with the red as supplied.

Engine Cooling Fan

Unless the air conditioning is on, whether driving or stationary, the engine cooling fan only turns on when the cooling system is hot enough to demand it.  The fan is always on when the air conditioning is running.

Basic check:

This is the schematic for the engine cooling fan.

Most failures appear to be the fan itself.

This is the external relay for the engine cooling fan.  Mounted on top of the radiator and shown back to front to make reading the number easier

Overheating problems

See the radiator fan circuit (above).  From the circuit you can see that the radiator fan fuse is MF1 which is hidden at the back of the  engine bay fusebox. 

Overheating symbol on the instrument panel

Overheating could be due to a failed fan (or circuit) or a thermostat failing to open.

The fan circuit can be tested using PP2000 (which is how I know my fans and circuits are OK). The temperature sensor controlling the ECU gives a reading on a code reader at the OBD port so it can be checked as OK.

The  temperature sensor  mounted on the thermostat housing has failed twice on my 1.6 petrol.  But that shouldn't cause overheating - just a confused ECU.

From other comments either the fan itself or the control relay on top are the more common faults.

Overheating symbol on the instrument panel

Milan Vojinović would like to share with the community a problem that has been bothering him for several months. It all started with a coolant temp to high message on the computer which is something I've encountered before. The error has been displayed,and after the fan starts working ecu immediately clears it. Sometimes the error was permanent. Of course, I first suspected the thermostat and temperature sensor, but that didn't fix the problem. Diagnostics found the error p0485 - cooling fuction incorporated in the ecu permanent.

The operation of the computer and the fan were checked, and the electrical lines from the computer to the fan and the temperature sensor were checked. Since everything was ok, it was suggested to replace the ECU. Done. But the error remained.

Next was the fan - fan electronics were checked and a fault was found on the board (inside fan housing) which confused the computer. I was told that it is a common fan malfunction in c2 c3 and peugeot 1007. So if someone has the same problem, the order of repair should be: thermostat, sensor (there is only one in the thermostat housing 1.4 8V petrol), fan (fan electronics).  The Ecu is the last one that should be changed because it is known that they break down very rarely.