Hi, I have a 52 Ford Focus 1.8TDDI. Ever since I acquired it last year it has had a coolant loss problem which is baffling me. Sometimes it loses 1 Litre of coolant in about 300 miles sometimes less, sometimes more. The problem is the Ford dealer and an Independant garage don't seem to know where it is going. Looking for tell-tale signs, I have found pink/red staining on the top of the starter (the first starter I had to replace as it was heavily corroded and failed). I can never seem to find any wet patches though. The thermostat housing SEEMS OK, but there is plenty of surface corrosion on one of the pipes on the metallic bypass pipework underneath. Are there any weak spots where it is common to lose coolant in this vicinity? There doesn't seem to be any evidence that it is a head gasket issue.
Just check the basics could be core plugs in the engine