Oil like substance in coolant reservior

laddyboy · Post by **laddyboy** » 17 May 2010, 08:22

I recently replaced the retaining clips for the trans. mission lines, the bottom line had a small leak. In order to do this I disconnected the coolant hose below the trans. cooling line, the coolant was a milky green. I was told that transmission fluid might be mixing with the coolant. Upon futher inspection I found that there is a dark oily substance in the coolant reservior, not red like trans. fluid, almost like engine/motor oil. After replacing the clips, I flushed the radiator of all remaining fluid and put in fresh coolant. After a day the oily substance returned in the reservior but the coolant is still a clear green. Any ideas as to what this may be.

cmblackburn · Post by **cmblackburn** » 17 May 2010, 08:32

If it looks like oil it might be oil...Do s80's have oil coolers built into the radiator? I know s70's do...

Post by **JDS60R** » 17 May 2010, 08:34

Most likely oil.

You should have a square oil cooler on the back of your engine. It needs to be tested and eplaced if it cant hold pressure.

If not then you have to suspect a head gasket etc.

Take a look at the oil and transmission fluid to see which one is getting cloudy or if you see steam coming off of it once it heats up.

laddyboy · Post by **laddyboy** » 17 May 2010, 16:00

Thanks for the quick and helpful responses guys. One more question, where can I find a diagram of the setup of my engine ( 99 s80 t6). thanks again