oil in my radiator Reservoir

[Rawze]

(01-31-2017 )Navarrotruckinginc Wrote:  hey guys couple weeks ago I noticed a film of oil on the top of my radiator Reservoir so I flush it out cleaned no oil for about 2 weeks then film appeared again.so wondering if its oil cooler seal or its the oil cooler itself.help?

The oil cooler is usually the most likely culprit on them. When the engine is running, the oil pressure is higher than coolant pressure. This means if there is a leak in the cooler, oil ends up in the coolant. After the engine shuts down though, there is usually pressure in the coolant system but no longer in the oil system. This means that coolant gets back into the oil too.