My 1.4 HDI (8 valve) cooling system appears to have problems. The dash board guage the series of amber/ red lights do not come on for a very long time after strtaing up, then leap to 3 or 4 bars, only to fall back to one or two bars. The engine seems very hot, even when one or two bars are lit on the dash but the cooling fan does not cut in. I have checked all fuses and connectors and I can turn the fan so it is not seized. The car also has aircon, but the fan does not operate when this is turned on, although I can hear the relays actuate. any ideas ?