hi my name is ian, I have had my c3 for nearly 6 years with not too much problems the usual wear and tear but the other day drove half a mile and the red temp light came on i thought i had low levels of coolant but was shocked to find the coolant reservoir full of thick black oil. The engine is clean and both the oil cap and dipsticks are clean no sign of water. The car still runs perfect so iam a little stumped ive had conflicted answers such as oil coolers and head gaskets. my baby is a c3 1.4 hdi 68hp and the year is 2005. has anyone else had the same problem. thanks