I just bought a 1992 Subaru Loyale wagon with the 5 speed transmission. I just recently did an oil change with heavier oil and now i have oil in my coolant reservoir. Now do these have a oil cooler that could of went bad or is it head gaskets? I only ask because it doesn't seem like i lost much or if any oil. I also checked under the cap on oil filler and there is nothing there and on the dip stick so its just my oil getting into my coolant. Any advice on what it might be?