Oil in my coolant header tank
I purchased a 147 1.6 t spark on a 02 plate.
All was going well, until I noticed I needed coolant.
I put in the recommended coolant and again all was going well.
1 week later, I checked the coolant in the header tank and it appears to be oil now.
It was still running fine and no overheating and the oil side seems well, no gunk etc.
I read on this forum it could be a oil heater exchange unit problem and not the head gasket.
As any one got any advice or guidance on this before I order this part?