Citroen relay 2016, overheating. . . .

[Citroenrelay2016]

Hey all,

I have a 2916 Citroen relay bluehdi 2.0 and it overheats on inclines recently.

Overheating on inclines.
New waterpump and belt and thermostat housing Inc thermostat 8months
New radiator 1month
New radiator fans 14months
No leaking seen.
No loss of fluids when driving only when it's overheated.

I hope this is helpful as I'm scratching my head, either a pipe is collapsing or the pump has failed again, were abroad with the van so it's a trick getting some one. Any advice on what you think it is?


Many thanks

[PaulC5]

Possibly the thermostat is not opening fully. A quick check would be to see if the radiator top hose gets hot. When it is getting hot put the cabin heater on max to help cool the engine.

[Citroenrelay2016]

Possibly the thermostat is not opening fully. A quick check would be to see if the radiator top hose gets hot. When it is getting hot put the cabin heater on max to help cool the engine.

Ah forgot to mention the stat was replaced when the pump was, the pipes are also getting hot. Putting the heater set to warm 0 slows the overheating and once it starts, blasting warm on full for a few seconds were engine temp back to normal.

[Citroenrelay2016]

So, it keeps happening up hills, the van isn't overloaded, sometimes flicking the heater on full doesn't produce hot air, maybe it's pointing to the thermostat. Hm

[PaulC5]

I would have thought a cold heater would not suggest a thermostat not opening fault but rather it being open all the time. A cold heater could be a sign of its heater flap not opening or an air lock or a blockage in the heater matrix and a check of its supply/return hoses being hot could help check these.

Have you used a code reader with live data to see what the engine coolant temperature is reaching and when the thermostat starts to open shown by the radiator top hose warming up ? The fan should not really be needed this time of year but is it coming on as the temperature rises ?

[Citroenrelay2016]

I would have thought a cold heater would not suggest a thermostat not opening fault but rather it being open all the time. A cold heater could be a sign of its heater flap not opening or an air lock or a blockage in the heater matrix and a check of its supply/return hoses being hot could help check these.

Have you used a code reader with live data to see what the engine coolant temperature is reaching and when the thermostat starts to open shown by the radiator top hose warming up ? The fan should not really be needed this time of year but is it coming on as the temperature rises ?

The day temps here go up to 25c, the rad fans kick on, Citroen in North Macedonia plugged it in but scratched their head as they reported no codes relating.

Be visiting Citroen in Greece for a second look but in the meantime I'll bleed the system, check for airlock.