white residue day after topping up oil
my Fiesta consumes a lot of oil so I have to top it up every few months. It was below MIN yesterday so I put half a litre in. I checked it again today and it was just on the MIN line so I decided to put the other half litre in. When I opened the oil filler cap I notice a white residue on the inside of the pipe. I know this can be a sign of a worn head gasket but the chances of that happening in a day are very slim. Could this just be impurities in the oil? or moisture from when the filler cap was off? It wasn't raining at the time.